Why you shouldn't modify cables on welding machines

[Commander_Keen]

We had a similar thread HERE (http://metalworkforums.com/f309/t202810-15-amp-plug) http://metalworkforums.com/f309/t202810-15-amp-plug, which sparked some interesting, yet poorly thought out discussion on changing 15A to 10A plugs on some machinery. I do a bit of this day-to-day, and can add some further value here to help educate as to the reasons why not to mess with your electrical equipment.

Below is some details of, and further reading on why you should NOT modify electrical cables for plant and equipment- in this instance, I've modelled this reply off a welding machine example- which many of us may be able to relate to.


Your welder has a data plate on it, and a few key bits of info- iMAX is the 'max current' the machine can draw when you give it the beans- a180A welder might top out at say, 25A current draw for a short peroid of time following arc initiation.
Another important value on the machine's data plat is the iEFF or 'effective current' the machine draws. Consider this the average current at max machine output that it will draw, after the current 'spike' has settled. This is calculated by electrical engineers using a formula as long as your arm.

In layman's terms, the machine draws current from the wall, the power point doesn't give it. A welder is just a gearbox for power - feed it 240V at 15A, and it will convert it into 'welding power' say, 12V, 170A for Stick welding, or 19V and 160A for MIG welding... or thereabouts- Ohm's law applies, but that's a whole different topic.
This above information dictates which power plug and subsequent circuit the machine needs to be used on. Small welders may use a 10A plug and circuit, but are usually only food to 130A. Larger machines, up to about 180A can run a 15A plug. Bigger machines again, a 32A plug, then we move into 3 pahse power etc.


So... On top of this all fits a whole raft of 'external' factors to the welder.
1) There is an Australian Standard that electricians use to dictate wiring practices in home, workshops and other places. Things like calculated draw on a 10A circuit, what circuit protection is used (circuit breakers in the meter box), cable cross sectional area (conductor CSA) etc etc. This includes the 'single 15A GPO on a 15A circuit' rule. Circuit protection can and does fail under higher loads than they are designed for. Ask any sparky for some pics of burnt our CB's and be prepared to be shocked.
2) Machine manufacturers need to abide by rules for the design of their machines- as designers they can be legally liable for faults in design which cause injury or death- this is the work health and safety piece, Graeme can probably give more info in this... As a result, point 3 applies:
3) Machine certification by manufacturers needs to account for a proper input cable size (ie the conductor CSA) and a 'suitable plug' fitted to the machine to meet it's iEFF current draw under maximum output (read 'worst case scenario') conditions. This is a stipulation of certification for the machine as a compliant to AS 60974, and for the Regulatory compliance mark (RCM) certification you should be looking for in a machine when purchasing.
As a result of this information, you'll start to see a number of machines in the 200+ amp range now be fitted with the big orange single phase (3-pin) 32A plugs...
4) Workplaces using machines like this will also go thru a testing and tagging program, which amongst other things, checks that the plug and circuit is up to the task of the appliance. not doing so is bad news for a PCBU (person undertaking a business or undertaking) if there is an injury or death, and the law and precedence of cases will certainly see you dragged thru a court or worse.

The whole idea of this is that the machine is engineered SAFE, meets standard, and the fitted plug is capable of safely working on the circuit which it is plugged into.

...with all this in mind, you could be a goose and run a non standard plug to make it work... but you'd also be tempting fate with multiple levels of engineering controlls being bypassed which are all there for your safety. Doing anything other than fitting it to a correct circuit is meddling with your safety and should not be done.




So, standards and other boring stuff aside, the extreme, but not-too-improbable scenario could go something like this:

An aspiring welder, Mr Richard Cranium, buys a nice new MIG welder, but blows all his coin on the machine, and is too cheap to get a proper power circuit installed for his 250A machine.
Being a bit creative, Richard removes the 32A plug fitted to the machine, thus voiding his warranty with the manufacturer, and fits a 10A plug so he can use in the the garage alongside his beer fridge. The fridge is an old kelvinator from the 50's and has given the circuit a bloody hard time over the past 35 years of use, keeping the beer cold at 1 degree inside the shed that routinely reaches 45 degrees plus ambient during a hot summer (all the while Richard makes use of said fridge every half hour thru most of the weekend). As a result the wiring is old, and the insulation is heat damaged within the walls. The circuit board, installed with the house in the 1940's, uses ceramic circuit breakers and fuse wire, and unbeknownst to Richard, the previous owner of the building purchased and installed the wrong fuse wire for the shed circuit, a fuse which was well higher than what the wiring can handle.
Keen to test out his new welder, Richard plugs his 250A welder into his 10A circuit, but not before moving it into his welding area with a 15m extension cord. 'Perfect' thinks Richard, as he reaches for some 12mm plate steel and unpacks his new spool of 1.2mm wire for his first test weld. 'I'll give her the beans!' he says as he turns the dial to 11 and proceeds his first weld... as his fridge compressor is busily working hard on the same circuit.
With this, the conductors (wires) in the wall melt, and ignite- the circuit protection has not done its job, as it was a 50A wire installed by mistake. Richard now has an electrical fire on his hands, in the walls of his shed, and unable to be extinguished.
The insurance assessors review the ashes of his house, and deny his claim. The manufacturer, who has all the certification for the machine in order, denies any liability or responsibility for the damages as a result of using the machine, as it was improperly modified.
Richard then continues to live the rest of his days on skid row, needing to pimp himself out for small change to stay alive, with no house, job or immediate prospects. "If only I didn't burn the house down" he mumbles to himself.


Be smart with your power, and stay safe. Don't be like Richard.

[lamestllama]

Sounds like you are giving legal advice to who Richard could or could not pursue in this matter. I would avoid giving legal advice unless permitted by The Legal Practitioners Act.

[KBs PensNmore]

I don't see it as giving advise, just a laying down of what COULD happen if you changed a plug on a machine.
Kryn

[BobL]

Still trying to come to grips with what the old fridge has to do with anything?

[simonl]

I see your point. The same situation could happen even if he had a dedicated circuit if the incorrect fuse wire was used or any number of dodgy stuff was done.

In the other thread I mentioned to change the plug from a 15A to a 10A. This is obviously dodgy but it's no better or worse than making up a 15A to 10A adapter extension lead. OK so it's better in the sense you can change it back and cover your dodgyness but in terms of the actual act, it's still using a 15A machine on a 10A circuit which is certainly not good.

Last week we attended a fuse box fire at a well known automotive store. A hot day with many things running in the store. Turns out the board had been "upgraded" from 3 x 50A circuits to 4 x 100A circuits with no change to the wiring or other necessary "stuff" It didn't end well! :oo:

Simon

[RustyArc]

I don't quite understand the example in the last paragraph either - if the wiring is in a poor state due to age, and the protective fuse for the circuit has oversized wire fitted, then *any* overload condition could cause a fire, there's nothing particularly special about a welder in that respect. Plugging 2 fan heaters into GPOs on the same circuit could achieve the same result.

As for the insurance boogey man that seems so popular in these parts, I've heard from actual insurance assesors that unless there's a death involved, there typically isn't a forensic investigation to drill down the the precise cause and who may be to blame. House burns down, they just pay the claim.

[BobL]

The legalities around fires are rarely cut and dried.

We had a small fire (~ 1 BBQ burner size) in a uni lab at work. Lost of black smoke from burning plastic when a $20k chiller caught fire at 5am in the morning and a student working overnight saw the fire through a window but couldn't get into the lab as it was locked so he called security. The security guard arrived and looked around for a fire extinguisher but he missed the sign on the door to the lab that said "in case of fire use only [water mist] extinguisher inside lab near the door" and instead grabbed a dry powder extinguished from the corridor and put out the fire. In doing so the ammonium phosphate did $1.5m worth of damage to the analytical equipment inside the lab. The fire could have been extinguished with a fire blanket - also hanging by the door.

The Lab was out of action for 18 months while a huge legal wrangle over who was to blame took place. In the end costs for equipment and operating losses were split between the manufacturer of the chiller (fires being reported in these chiller units around the world), the supplier of the chiller (who knew the chillers had probs), the employer of the security firm, and the Uni's insurer. I heard the insurer and suppler then sued the manufacturer - I have no idea if they got their money or not.

The silly thing was we never wanted to have the chiller inside the lab in the first place and we wanted to locate it in a weather proof box outside the building but Admin said it would spoil the (red brick and exposed concrete 60's) architecture of the buildings. What a flaming joke.

[simonl]

Yea, dry powder extinguishers are great at putting out Class A, B and (E) fires but they create a massive mess and can actually cause more damage and higher cleanup costs than the fire itself.

Certainly for around the home a fire blanket are the best. I also have a vapourising liquid extinguisher which are awesome too.

It's not unusual for people in the heat of the moment to make a situation worse not better. I think it would be harsh to blame the security guard though without knowing what training he had and seeing his induction program before he started working at the establishment. People are less likely to read signage during stressful situations.

Luckily for me, any damage done by firefighters during firefighting operations is deemed (by act of parliament) to be fire damage! :2tsup:

Having said that, we make sure that specific risks in our area are understood and we know what extinguishing media can and can't be used. It's not very professional if we attend a fire and cause $100,000 damage when the fire damage is maybe only $50,000.

Simon

[Commander_Keen]

Sounds like you are giving legal advice to who Richard could or could not pursue in this matter. I would avoid giving legal advice unless permitted by The Legal Practitioners Act.
So you have to be Geoffrey Robertson QC to pose a hypothetical around here? Dream on buster...


Still trying to come to grips with what the old fridge has to do with anything?
Besides the Fridge being the source of the most essential workshop consumable, It is an example of what may cause a compromised circuit, also adding additional heavy load to the circuit. In actual fact it could be a number of other appliances, or in severe cases, just one appliance with a large power requirement well and truly above the capacity of the circuit.

[BobL]

It's not unusual for people in the heat of the moment to make a situation worse not better. I think it would be harsh to blame the security guard though without knowing what training he had and seeing his induction program before he started working at the establishment. People are less likely to read signage during stressful situations.

I'm pretty sure he was trained and I don't think it was that stressful - It's not like the whole room was on fire.. But I don't blame him that much. If anything I want to blame the ning-nong administrator who wouldn't let us locate teh chiller outside.

[BobL]

So you have to be Geoffrey Robertson QC to pose a hypothetical around here? Dream on buster...
Besides the Fridge being the source of the most essential workshop consumable, It is an example of what may cause a compromised circuit, also adding additional heavy load to the circuit. In actual fact it could be a number of other appliances, or in severe cases, just one appliance with a large power requirement well and truly above the capacity of the circuit.

The way I read it the fridge just colours and pads out the story and, "all the while Richard makes use of said fridge every half hour thru most of the weekend" implies Richterd is an alky and all round general lower life form, but IMHO it would be deemed irrelevant by most magistrates.

A fridge is still handy equipment for my operations but not for alcohol as I rarely drink it. However, I do use it for storing certain chemicals, adhesives and dog bones/food.

[.RC.]

I don't see it as giving advise, just a laying down of what COULD happen if you changed a plug on a machine.
Kryn

Like the other thread I still call rubbish. The standards are not based on engineering principle. Lets say Richard Cranium instead of buying a welder has a four port 10 amp GPO outlet installed., his beer fridge is churning away, then in the same GPO he decides to cook some food, so plugs in one of those portable ovens to cook some fish and chips. Then he still has two spare ports on the same GPO, so he plugs in the kettle to boil some water. He is also a bit of a preener so decides to plug in his hair dryer and do his hair.

He is pulling far far far more amps then if he had his welder plugged in with the adapter, but that is all fine and dandy. His shed burns down and the insurance agent see's all the items plugged in and says. Don't worry, that is acceptable under the electrical guidelines, here is your money.

I am not saying it is fine to do it, I am saying the rules are not based on engineering principle. What the rules probably say though that all wiring must be able to handle the amperage of the fuse. My shed the single 15 amp GPO and the six ten amp GPO's both use an identical fuse, that being 20 amps.

[Karl Robbers]

One point to further muddy the waters is that many welders come with a 15A plug attached from the factory when their actual power demand is closer to 25A. They also have a nice little sticker attached to the power cable stating that to achieve maximum output a higher capacity circuit must be used. Who reads this and abides by it for a start and secondly how will joe public know when the upper limit of the 15A supply has been reached?
It is unlikely that anyone will put in writing the permission to use a 10A to 15A "naughty lead", however we all know there are an awful lot in service out there and you will find that the wiring used in a 15A lead is thinner than the wire used to connect the 10A GPO in most cases.
Those wishing to use such adaptor leads will need to make their own minds up. I would also add that there are far more likely causes of an electrically caused house fire than the 10 to 15A lead.

[lamestllama]

So you have to be Geoffrey Robertson QC to pose a hypothetical around here? Dream on buster...


The person who modified the fixed wiring design by installing incorrectly sized fuse wire is the person responsible for this fire, yet you try to apportion 100% of the liability in Richard's direction . The more likely outcome is Richard gets his insurance or most of it paid out (because he didn't create the dangerous situation in the fixed wiring of his house) and gets a house with modern wiring and at some time in the near future realises he can't be bothered with his welder tripping the circuit breaker so he gets himself a 32A outlet installed.

A scenario as realistic as the original proposal is that he decides to emigrate to NZ where he can do his own electrical work using the same AS/NZ standards and participate in a system that kills less people per capita through electrical faults than does our highly regulated system. This would the give him the option of correctly installing his own 32A outlet and associated circuit thus avoiding reliance on substandard work done by others or the motivation to do dodgy workarounds because he isn't legally allowed to do the right thing.

[jack620]

The standards are not based on engineering principle.

Where did you get that info?



What the rules probably say though that all wiring must be able to handle the amperage of the fuse.

AS3000 pretty much says that.

[Commander_Keen]

Like the other thread I still call rubbish. The standards are not based on engineering principle.
I disagree, but happy to hear your point as to why you think there is an absence of engineering principle in the standard. Have you read it? You can purchase it here (https://infostore.saiglobal.com/en-au/Standards/AS-60974-1-2006-121167_SAIG_AS_AS_254261/)



One point to further muddy the waters is that many welders come with a 15A plug attached from the factory when their actual power demand is closer to 25A. They also have a nice little sticker attached to the power cable stating that to achieve maximum output a higher capacity circuit must be used. Who reads this and abides by it for a start and secondly how will joe public know when the upper limit of the 15A supply has been reached?
So... this was correct, now not so.
Machines used to be able to be certified using an under-rated plug, for the purposes of 'demonstration' by the retailer, or for machine setup. The Label to have the machine fitted with the supplied larger CSA cable and plug was to ensure that it was all above board.
The certification process now requires the machine to be sold in the same condition as it was presented for certification- so hence, most larger machines now have a large input cable and plug fitted.
The devil in the detail though- some machine suppliers simply don't get their machines certified, and sell the machine however they wish. This puts the consumer at risk.
Some of the more unscrupulous suppliers have massaged their stated duty cycle and iMAX values for their machines to sneak a machine in under the 15A iEFF rating to allow them to fit a smaller plug - essentially fudging the data to their own benefit. When this data is enetered into the calculation formula, it is in their favour. If you are like me and like the late 80's / early 90's japanese cars, it's similar to the power output 'gentleman's agreement' of a capped 290 HP that the GTR Godzilla, supra, and other hot cars of the day all made.
In the end of the day, there is no free lunch with a welder- you want to weld big, you need to supply big power.



The person who modified the fixed wiring design by installing incorrectly sized fuse wire is the person responsible for this fire, yet you try to apportion 100% of the liability in Richard's direction . The more likely outcome is Richard gets his insurance or most of it paid out (because he didn't create the dangerous situation in the fixed wiring of his house) and gets a house with modern wiring and at some time in the near future realises he can't be bothered with his welder tripping the circuit breaker so he gets himself a 32A outlet installed.

A scenario as realistic as the original proposal is that he decides to emigrate to NZ where he can do his own electrical work using the same AS/NZ standards and participate in a system that kills less people per capita through electrical faults than does our highly regulated system. This would the give him the option of correctly installing his own 32A outlet and associated circuit thus avoiding reliance on substandard work done by others or the motivation to do dodgy workarounds because he isn't legally allowed to do the right thing.

The problem begins by our mate illegally modifying an appliance. Secondly, as a home owner, he probably should have also maintained or at least had inspected his home for faults, which if it was, circuit breakers would have been installed to the 21st century spec. If this was the case, they would most likely trip, and he'd be safe. So on the latter part, I think we agree.

The NZ argument though- that's an obvious straw-man- unless you want to provide some reputable per-capita stats to back it up?
Heck, if we lived in downtown Dehli, we'd just throw a wire onto the transformer, right?! I went there- you'd get a brown out every hour, and households would have transformer / capacitor units to smooth out the power to protect the TV/ computers etc from these spikes. I can't help but think every brown out was a short to earth thru some poor Indian bloke who found himself between the active and earth...

I for one, in no way resent the fact that we have a system that requires a licensed tradesperson to work on electrical installations. Could I do it myself- sure I could, but overall it's a safer proposition to have it within the scope of work of a professional.

[jack620]

This would the give him the option of correctly installing his own 32A outlet and associated circuit thus avoiding reliance on substandard work done by others or the motivation to do dodgy workarounds because he isn't legally allowed to do the right thing.

Pretty sure the NZ rules don't allow a non-sparky to do their own fixed wiring.

[Karl Robbers]

So... this was correct, now not so.
Machines used to be able to be certified using an under-rated plug, for the purposes of 'demonstration' by the retailer, or for machine setup. The Label to have the machine fitted with the supplied larger CSA cable and plug was to ensure that it was all above board.
The certification process now requires the machine to be sold in the same condition as it was presented for certification- so hence, most larger machines now have a large input cable and plug fitted.
The devil in the detail though- some machine suppliers simply don't get their machines certified, and sell the machine however they wish. This puts the consumer at risk.
Some of the more unscrupulous suppliers have massaged their stated duty cycle and iMAX values for their machines to sneak a machine in under the 15A iEFF rating to allow them to fit a smaller plug - essentially fudging the data to their own benefit. When this data is enetered into the calculation formula, it is in their favour. If you are like me and like the late 80's / early 90's japanese cars, it's similar to the power output 'gentleman's agreement' of a capped 290 HP that the GTR Godzilla, supra, and other hot cars of the day all made.
In the end of the day, there is no free lunch with a welder- you want to weld big, you need to supply big power.

I for one, in no way resent the fact that we have a system that requires a licensed tradesperson to work on electrical installations. Could I do it myself- sure I could, but overall it's a safer proposition to have it within the scope of work of a professional.
When did the rules change regarding supplying machines with undersized plugs for commissioning purposes? The machines that I have seen this on were not fly by night ebay specials,so I would be inclined to think that they would have been compliant and certified to the relevant AS. Cigweld is certainly doing it and I can find references in the Fabgear catalogue for 2017. Fabgear are quite open about it and state the fact in large print while Cigweld put it in the finer than fine print.
I cannot say that I have the same warm fuzzy feeling towards electricians. Despite what they may like to believe, they are not living gods, nor can they walk on water. I have personally seen two monumental stuff ups by two separate sparkies that could have caused loss of life. One was running a heavier cable to prevent excessive voltage drop on a pressure pump installation on a rural home, (why the previous sparkie didn't put in adequate wiring is another question I guess). The wire was run and connected to the board with a new D curve breaker and the pump commissioned with good results. That was until quite by accident the old wiring was found shoved into a bundle in the corner of the pump shed, still very much live and with lovely bare wires waiting to zap someone. The second instance was when my workplace was putting power onto our second shed. Previously we had run extension leads as required, but this was both tedious and unsafe. We enlisted the services of a sparkie and while we had to keep a close eye on what they did, (why don't sparkies listen???), the work was completed - or so we thought. Running a single phase plasma cutter the circuit breaker tripped. When I went to reset it, I noticed two things. Firstly, the breaker was only a C curve and we had requested D curves due to running welders etc, secondly, the plastic plugs covering filling in where extra breakers could be fitted were missing and a very live bus bar was easily within finger poking distance. We reported this to said sparkie and he said that he'd "try to get there some time to fix it, just don't stick your fingers in there till I do." The final straw was when Tech Safe called in to do an audit of the installation, they found that there was no earth connected to the new shed whatsoever. Based upon these experiences, I really fail to see how I could do worse.
You seem pretty sure of your facts and you made the statement that you had done a bit of this before Commander_Keen. What is your actual background and prior experience with matters electrical? Our membership here comes from many diverse areas and there is a lot of knowledge and combined experience that you may be able to add to.

[.RC.]

Where did you get that info?




As I explained, you can buy 4 port 10amp GPO sockets. In fact counting 10 amp GPO's in the house here there are around 25 sockets per fused circuit.

Yet you can have only one single 15 amp GPO per circuit.

[Karl Robbers]

Pretty sure the NZ rules don't allow a non-sparky to do their own fixed wiring.
Check this link from the land of the long white cloud. https://worksafe.govt.nz/managing-health-and-safety/consumers/safe-living-with-electricity/getting-electrical-work-done/doing-your-own-electrical-work/
It sounds like you may be able to work from a Sub Board onwards, but not from the initial board.

[jack620]

Looks like you're right Karl. Lucky buggers.

[jack620]

As I explained, you can buy 4 port 10amp GPO sockets. In fact counting 10 amp GPO's in the house here there are around 25 sockets per fused circuit.

Yet you can have only one single 15 amp GPO per circuit.

Right, but how do you get from that to this:


The standards are not based on engineering principle.

[pipeclay]

All the disclaimers mentioned, I have a short piece of cable that I use if required ( 300mm ) with the appropriate fittings that I have had for over 10 years and used when required,as a non electrician I would say use it,the only exception that I would consider is if you intended using it for extended periods ( more than 20 mins constant welding ).
Based on what Bunnings have I would think 20 mins would be well above there duty cycle.

[Theberylbloke]

Well this seems to have fired a few people up! lol.

Full disclosure - I'm a sparky who works for the local electrical distribution company, I inspect new switchboards and, all being well, connect them to the mains. I also do other stuff though I cannot walk on water, sometimes I have lead feet etc. I may be out of date with the latest rules as well given there has recently been a new version of AS3000

In general, I agree with OPs opinion, non electrically qualified people doing their own electrical work can lead to less than optimum outcomes. Sometimes, having qualified contractors also leads to less than optimum outcomes. Some are really good and others don't seem to have much of an idea. Guess that's the same as in any other field. Electrical work covers a wide gamut of tasks and some sparkies are very good at a few of those tasks and somewhat less good outside of those.

Commander Keen you included this in your original post "This includes the 'single 15A GPO on a 15A circuit' rule. Circuit protection can and does fail under higher loads than they are designed for"

Once upon a time AS3000 specified how many 10A GPOs (points in electrical talk) could be connected to a single circuit. This got changed several times to end up "as many as you like" keeping in mind the likely hood of circuit breaker protection operating i.e. nuisance tripping. I am paraphrasing all of this. i.e. the circuit relys on the protection operating to prevent overload. I also understood that you can now put one 15A GPO on a general power circuit. This may have changed???

I am seeking understanding from you about "Circuit protection can and does fail under higher loads than they are designed for". Circuit breakers do not immediately trip when the load goes above their rating, rather the time to trip is inversely proportional to the current. Thus say a 15 amp breaker may take quite some time to trip at 16 amps of load. So are you saying that if a 15A breaker is cycled to 16A, but for not long enough to trip, and such cycling is on a regular basis it is likely to fail? If that is what you are suggesting then I would consider that 15A circuit breaker "not fit for purpose"!! Also a pile of burnt out circuit breakers may be proof that the electrician did not make the connection to the wires tight enough thus causing a hot joint to form. The only way to be sure that load caused a circuit breaker to fail is to measure the load after the failed breaker has been replaced. Even then the breaker should trip to clear what it sees as a fault rather than be damaged. Perhaps you can provide some more clarity around you comment?


R.C. - Pretty sure the electrical standards (there are quite a lot, AS3000, AS3008, AS3017, AS3077 to name a few) are based around a mixture of engineering standards and practical input. The replacement of a single outlet GPO with a 4 outlet GPO doesn't really change anything in that the circuit is still reliant on the protection to trip before there is any damage. Thus you could put 100 GPOs on one circuit in your shed, you still can't get more than 20 Amps total. There would be no "nuisance trips" as they would all be "major PITA" trips as you went about finding the fault, turning equipment off to allow other equipment to run etc. BTW those 4 outlet GPOs are great just wish they were cheaper.

Just to clarify, wiring should be selected to handle the load of the circuit, voltage drop and loop impedance considerations along with how the wiring is installed then an appropriately rated protective device chosen. Maybe this is what you meant?

[.RC.]

The replacement of a single outlet GPO with a 4 outlet GPO doesn't really change anything in that the circuit is still reliant on the protection to trip before there is any damage. Thus you could put 100 GPOs on one circuit in your shed, you still can't get more than 20 Amps total.

That is my point.

Plug in two items on the same GPO and draw 4800W and that is fine

Make an adapter for a 15 to 10 amp and plug that in and draw 3600W through the exact same circuit and holy hell some seem to think it is akin to molesting children.

[Karl Robbers]

That is my point.

Plug in two items on the same GPO and draw 4800W and that is fine

Make an adapter for a 15 to 10 amp and plug that in and draw 3600W through the exact same circuit and holy hell some seem to think it is akin to molesting children.

I can't argue with that at all.

[jack620]

Molesting children. Wow, that escalated quickly.

Perhaps the contacts in a 15A GPO have a greater contact area than those in a 10A GPO? There has to be some reason why 15A GPOs exist.

[Com_VC]

The contacts for Active and Neutral are the same, it is just the earth pin that is larger on the GPO

With a 20A GPO the contact pins for Active, Neutral and Earth are the same size as the earth on a 15A plug.

[Karl Robbers]

Molesting children. Wow, that escalated quickly.

Perhaps the contacts in a 15A GPO have a greater contact area than those in a 10A GPO? There has to be some reason why 15A GPOs exist.
I have pondered the same question and the answer I came up with was that the sole reason for their existence was to act in a way similar to an unleaded fuel nozzle, I.E. to prevent the incorrect socket being used for higher rated equipment. Other examples exist such as 10, 15 and 20A 3 phase plugs. All use the same diameter pins and the same layout, however the shaping of the block holding them means that a 20A outlet will accept the lower rated plugs, but a 10A outlet will not accept the 20A plug. A similar case exists with 32A and 50A 3 phase outlets. This would have made sense back when 15A GPO's were installed on their own dedicated circuits but has lost some relevance now that it seems that they can be installed in multiples at the sparkies discretion. Having decomposed both 10A and 15A GPO's, I can find no difference in their construction internally.

[jack620]

Having decomposed both 10A and 15A GPO's, I can find no difference in their construction internally.

This guy came to the same conclusion: https://www.renovateforum.com/f195/there-any-difference-between-10a-15a-gpo-73298/

[Commander_Keen]

When did the rules change regarding supplying machines with undersized plugs for commissioning purposes? The machines that I have seen this on were not fly by night ebay specials,so I would be inclined to think that they would have been compliant and certified to the relevant AS. Cigweld is certainly doing it and I can find references in the Fabgear catalogue for 2017. Fabgear are quite open about it and state the fact in large print while Cigweld put it in the finer than fine print.
There is an approval process for the sale of electrical articles. Electrical items fall into either 'Declared' or 'non-declared' categories. Welders can fall into either of these two categories-
A single phase machine with a 100% duty cycle of <65A is a Declared item.
If a machine is 'an arc welding machine promoted exclusively to industry', then it becomes a non-declared item.
Declared need to be independently tested. Non declared may be tested, but need to meet at minimum AS3820:2009 -Essential safety requirements for low voltage electrical equipment.
Part of the approval process is that the machine is certified 'as tested', so if you sell a machine other than how the testing organisation viewed it, it's no longer compliant, and you go thru it all again.



You seem pretty sure of your facts and you made the statement that you had done a bit of this before Commander_Keen. What is your actual background and prior experience with matters electrical? Our membership here comes from many diverse areas and there is a lot of knowledge and combined experience that you may be able to add to.
Let's just say I work in sales for a company that (among many other things) sells welders. My daily job exposes me to many people who sometimes have little understanding of what can go wrong if these types of machines are not treated with a bit of respect, and there is a strong education piece around this.
I am not an electrician. I am tertiary trained in science and business, smart enough to know more than I probably should about many things, and dumb enough to keep learning it.




Commander Keen you included this in your original post "This includes the 'single 15A GPO on a 15A circuit' rule. Circuit protection can and does fail under higher loads than they are designed for"

Once upon a time AS3000 specified how many 10A GPOs (points in electrical talk) could be connected to a single circuit. This got changed several times to end up "as many as you like" keeping in mind the likely hood of circuit breaker protection operating i.e. nuisance tripping. I am paraphrasing all of this. i.e. the circuit relys on the protection operating to prevent overload. I also understood that you can now put one 15A GPO on a general power circuit. This may have changed???

I am seeking understanding from you about "Circuit protection can and does fail under higher loads than they are designed for". Circuit breakers do not immediately trip when the load goes above their rating, rather the time to trip is inversely proportional to the current. Thus say a 15 amp breaker may take quite some time to trip at 16 amps of load. So are you saying that if a 15A breaker is cycled to 16A, but for not long enough to trip, and such cycling is on a regular basis it is likely to fail? If that is what you are suggesting then I would consider that 15A circuit breaker "not fit for purpose"!! Also a pile of burnt out circuit breakers may be proof that the electrician did not make the connection to the wires tight enough thus causing a hot joint to form. The only way to be sure that load caused a circuit breaker to fail is to measure the load after the failed breaker has been replaced. Even then the breaker should trip to clear what it sees as a fault rather than be damaged. Perhaps you can provide some more clarity around you comment?

Just to clarify, wiring should be selected to handle the load of the circuit, voltage drop and loop impedance considerations along with how the wiring is installed then an appropriately rated protective device chosen. Maybe this is what you meant?

For the 15A GPO on a general power circuit- I've not undertaken this work myself, but have heard of sparkies going either way with the install. Some might see it as a low risk, whack it on and make it a gravy job, others give it a bit more thought and academic rigor. In the end of the day, their job and their licence is on the line.

As for the latter question- I'm sure we're on the same page here, maybe my delivery was off...
I think my original point is that there are multiple engineering controls (heirarchy of controls, if you are the HSE/OHS type) that act in layers to prevent 'bad things' happening.
For Electrical installations, the device has to be fitted with a plug based on what sort of load it could put on the circuit. As such, the electrican installs an outlet / GPO to suit this plug, but also ensures that the cabling is specced accordingly, like you said, Voltage drop, resistance, etc. On top of this all, the circuit breaker is the weak point in the whole scenario. Likewise, when a business has their equipment test and tagged, equipment can be tagged out if not compliant, or passed if deemed safe.
When an individual starts deconstructing these layers of control, the likelihood of a problem eventuating in normal use increases. Particularly so when we are talking not about a 16A load on a 15A rated circuit, but operating at 2-3 times the design of the circuit, say a 250+Amp welder with an effective current of >28A on a 10A circuit (trust me, I've seen it). In these cases, small problems quickly become larger ones if one piece of the system is not up to scratch. It may be a problem, or it may not. But the consequences can be significant, hence put faith in the trades, the standard, and the certification behind it all.

[.RC.]

say a 250+Amp welder with an effective current of >28A on a 10A circuit

But how is it going to get past the fuse?

Ceramic fuses that you can hotwire with #8 fencing wire are not that common these days.

[quote]

[Karl Robbers]

There is an approval process for the sale of electrical articles. Electrical items fall into either 'Declared' or 'non-declared' categories. Welders can fall into either of these two categories-
A single phase machine with a 100% duty cycle of <65A is a Declared item.
If a machine is 'an arc welding machine promoted exclusively to industry', then it becomes a non-declared item.
Declared need to be independently tested. Non declared may be tested, but need to meet at minimum AS3820:2009 -Essential safety requirements for low voltage electrical equipment.
Part of the approval process is that the machine is certified 'as tested', so if you sell a machine other than how the testing organisation viewed it, it's no longer compliant, and you go thru it all again.

Very interesting. So can we assume that a machine greater than 65A @100% is deemed to be marketed exclusively to industry and thus "non declared" for the purposes of certification? That would mean that a very large number of machines, if not the vast majority would fit into that category.
Your example of the 250A welder drawing 28+ Amps is very accurate and one that I have personal experience of. As I mentioned a previous workplace had a second shed wired in. In that shed we ran a 270A single phase mig. Do you know what the sparky fitted to run the machine from? A 10A GPO fed from a C curve breaker. Obviously not all sparkies are created equal.
I strongly suspect that more 15A gear has the earth pin ground down or is run from converter leads than is ever plugged into 15A GPO's to be honest. I understand the rules and the reasoning, but realistically it just doesn't happen that way. It also seems that many sparkies do not exactly work to code either.

[Pumpkinate]

A bit off topic, but I have just gone the other extreme when I got 3 phase connected... to keep my options open I said make the sub-board in the shed good for 50kW. The cable to the shed is as thick as my thumb!

[Chas]

As I explained, you can buy 4 port 10amp GPO sockets. In fact counting 10 amp GPO's in the house here there are around 25 sockets per fused circuit.

Yet you can have only one single 15 amp GPO per circuit.

Could you please provide a reference for this oft-quoted statement? My copy of AS/NZ 3018-2001 'Electrical Installations - Domestic Installations' has on p62 a Table 6-1 "Guidance on the number of points per final subcircuit" which clearly sets out the circuit conditions for one, two, or three 15A socket outlets per circuit. For a common 2.5mm2 wired circuit protected by a 20A circuit breaker, two 15A outlets are allowed except when the wiring is completely surrounded by thermal insulation -Item(I). Three 15A outlets are permitted on a 25A circuit with the wire gauge dependant on the installation method used.

Chas.

[BobL]

Could you please provide a reference for this oft-quoted statement? My copy of AS/NZ 3018-2001 'Electrical Installations - Domestic Installations' has on p62 a Table 6-1 "Guidance on the number of points per final subcircuit" which clearly sets out the circuit conditions for one, two, or three 15A socket outlets per circuit. For a common 2.5mm2 wired circuit protected by a 20A circuit breaker, two 15A outlets are allowed except when the wiring is completely surrounded by thermal insulation -Item(I). Three 15A outlets are permitted on a 25A circuit with the wire gauge dependant on the installation method used.

Interesting that the table header says "Guidance".

[lamestllama]

The NZ argument though- that's an obvious straw-man- unless you want to provide some reputable per-capita stats to back it up?
Heck, if we lived in downtown Dehli, we'd just throw a wire onto the transformer, right?! I went there- you'd get a brown out every hour, and households would have transformer / capacitor units to smooth out the power to protect the TV/ computers etc from these spikes. I can't help but think every brown out was a short to earth thru some poor Indian bloke who found himself between the active and earth...



The NZ argument is certainly not a straw man and I am surprised with your interest in electrical safety you are not already aware of the meticulous statistics kept by the Electrical Regulatory Authorities Council?

You can find the latest at http://www.erac.gov.au/images/downloads/ERAC%20-%20Electrial%20fatality%20benchmarking%202017-2018.pdf

For the last few years NZ has certainly had less deaths people per capita by reason of electrocution see Graphs 1.2 and 1.6 of the above document. To say "it's a safer proposition to have it within the scope of a professional" is clearly difficult to justify when the data collected by the regulatory authorities indicates otherwise. Perhaps if we had more decisions based on evidence we might see even better outcomes?

I for one would have liked the opportunity to tighten those two screws (left loose by two separate electricians) that left two circuits smouldering away in at my place. One in the shed and one in the house. Two separate certificates of compliance provided to me meant nothing, the work was dangerous. Who ever devised a system where you certify your own work?

Back to the hypothetical. I am lucky I didn't end up with Richard on skid row due to depression brought on by a system that allowed a pair of dullards to risk the lives of my family and myself whilst a safer system that would have avoided that outcome operates only a short flight away.

[Karl Robbers]

The NZ argument is certainly not a straw man and I am surprised with your interest in electrical safety you are not already aware of the meticulous statistics kept by the Electrical Regulatory Authorities Council?

You can find the latest at http://www.erac.gov.au/images/downloads/ERAC%20-%20Electrial%20fatality%20benchmarking%202017-2018.pdf

For the last few years NZ has certainly had less deaths people per capita by reason of electrocution see Graphs 1.2 and 1.6 of the above document. To say "it's a safer proposition to have it within the scope of a professional" is clearly difficult to justify when the data collected by the regulatory authorities indicates otherwise. Perhaps if we had more decisions based on evidence we might see even better outcomes?

I for one would have liked the opportunity to tighten those two screws (left loose by two separate electricians) that left two circuits smouldering away in at my place. One in the shed and one in the house. Two separate certificates of compliance provided to me meant nothing, the work was dangerous. Who ever devised a system where you certify your own work?

Back to the hypothetical. I am lucky I didn't end up with Richard on skid row due to depression brought on by a system that allowed a pair of dullards to risk the lives of my family and myself whilst a safer system that would have avoided that outcome operates only a short flight away.
It would certainly seem that you have a point. Even when taking into account the much smaller population of New Zealand, they still come out ahead. Looking at table 4. Fatal Electrical Accidents since 2000, the tally for Australia is 314 fatalaties for the period 2000-2018, while New Zealand registers 56. Let us assume that New Zealand has a population 1/5th that of Australia, so that would adjust the figures to 314 and 280 respectively. Still a clear advantage to the Kiwi's.

[jack620]

You can find the latest at http://www.erac.gov.au/images/downloads/ERAC%20-%20Electrial%20fatality%20benchmarking%202017-2018.pdf

Interesting that there have been no electrocution deaths in NZ in the last two years, despite the Kiwis being able to perform some DIY electrical work.

I wonder what the Electrical Trades Union would have to say about that?

[lamestllama]

It would certainly seem that you have a point. Even when taking into account the much smaller population of New Zealand, they still come out ahead. Looking at table 4. Fatal Electrical Accidents since 2000, the tally for Australia is 314 fatalaties for the period 2000-2018, while New Zealand registers 56. Let us assume that New Zealand has a population 1/5th that of Australia, so that would adjust the figures to 314 and 280 respectively. Still a clear advantage to the Kiwi's.

Graph 1.6 does the work for you it is per capita so it takes into account the differences in population. Not only does NZ have a lower electrocution rate but if you look at the slope of the linear regression lines you can see that NZ is reducing its rate of electrocutions at a faster rate than Australia.

[lamestllama]

Interesting that there have been no electrocution deaths in NZ in the last two years, despite the Kiwis being able to perform some DIY electrical work.

I wonder what the Electrical Trades Union would have to say about that?

The answer is nothing nor do any of their cheer squad, just watch.

[.RC.]

Could you please provide a reference for this oft-quoted statement?

I have erroneously been quoting what others have said. All the 15 amp GPO's here are single circuits.

[BobL]

Slightly off topic by I occasionally wonder about a bunch of things related to electricity like how utterly clueless most people are about the dangers of electricity compared even dare I say it to motor vehicles, and why machines are not fitted with simple $2 ammeters.

Users of motor vehicles require require some training yet very little little is provided regards electrical safety training for the general public or for that matter even in the workplace. Instead we "nanny state" it and try and make everything as protected as possible. Vehicles will probably only every get to that level when they are driverless.

I taught 7 year of High school physics and the fact that only a few % of students do this subject to even a basic depth is just one of many problems. The other thing to remember is it is possible to "pass" high school physics, but completely fail the section on electricity.

Then I taught basic and advanced physics and electricity subjects at Uni for ~25 years and what I saw was the knowledge that students came in with was woeful to say the least and not much better when they graduated. I regularly conducted pre and post test using simple DC circuits ie globes and batteries and how much current is needed to kill some one. I have to say the results were very depressing. Even students that arrived with electrical and related trade certificates, some upgrading their qualifications to engineering degrees, had a very limited fundamental understanding of electricity. The most unusual students I taught were two 30 something ex-SAS specialists starting their engineering degrees. They had extensive training and field field in electrical circuits related to explosive devices but had a surprisingly poor understanding of electricity itself.

During my time at Uni I participated (ie I was a subject or participant) in a research project conducted by a PhD student on the depth of knowledge and understanding about electricity form primary school age through to fully experienced electrical engineers and how these people were taught about electricity. School and uni curricula were assessed in terms of the time spent and the way students were taught. The results were unsurprising, electricity occupies a very small portion of basic science curricula and like almost all subjects student were taught using only "models and algorithms" and students stick to these like glue when they should be moving up the ladder of fundamental understanding and we leave it to the students to make the leap to deep understanding and generalised cases. Often the exams might test generalised cases usually without teaching the students about it, and naturally this is where students generally poorest poorest at.

My experience in dealing with sparkies has been mixed. Some of them are fantastic - the 80 year old sparky at our mens shed is great, thorough, careful, and from the "sneaky" questions I ask him he really knows what he's doing. Some, I cannot for the life of me understand how they ever got a cert. Most sparkies (like most people) operate at what is called an "algorithmic" or "procedural" level because this how they are taught. EG Here are the steps to solve this problem - don't worry about understanding them, just remember them. These procedures are usually designed to keep them and the public as safe as possible. However, to cope with as many eventualities as possible, eventually all procedures/regulations/installation standards become complex, unwieldy and harder to remember and unfortunately simply cannot cover all possible situations. Unless a person has a deeper fundamental knowledge of the topic they may then get it wrong.

I reckon one of the main reasons for this is that less and less time is allocated to studying anything at tafe/uni and in particular hands on (lab/prac) time has been cut by the bean counters by about half.

As people get more and more life experience and life practice they will come across more cases and build their experience and knowledge base up but this is neither a fast or safe way to learn. An extreme case is bomb disposal where the ground rules can change on a daily basis and they have limited ways of learning other than by example and is why they have such high death rates.

So my ramble brings me back to where I started and that is electricity should be more prominent in school science and we should encourage more students to study electricity in general to a greater level and there should be more public education about about it. The odd ad on TV about staying away from fallen power lines is useful, but woefully inadequate.

Now lets get to the $2 ammeter.
It's mandatory that vehicles have speedometers so users should know how fast they are going and what limits to stick to but it's very rare to see a simple V/I indicator device fitted to an electrical appliance. I contend especially larger machinery should have a V/I meter fitted within easy operator view and a blurb in the manual to explain how to use the meter in relation to usage. Even the fact that is says what the V/I is at any given time would help users better appreciate what is a low current/load and what is a high current/load and the 240V is NOT always 240V etc.

I have an ammeter on all my 4HP machines, WW BS, compressor and Dust collector while for other machines and tools I have a short extension cord with a VI meter in the middle and find and find it really useful. Experienced users who already have a feel for machinery would not need it but I reckon newbies especially could benefit greatly while they get the feel of the machinery. One some machines running on VFD I sometimes monitor the current that way but usually the single line display is left on frequency which is where dual line display VFDs come in handy

On simpler/simpler appliances it does not even have to be a meter - it could be an indicator light like on a dash - thing goes orange or red - think about what this means. It could be your blades are blunt or you have another extra load. We're'e starting to see these load indicators on power tool batteries - why not have them for the tool itself

Instead of doing something useful like this we have fridges connected to the internet that tell you when to order more food - how arsed about its this?
Yes, initially the meters and indicators could create a some initial confusion but there would also be many useful learning opportunities come out of it.

Ramble over.

[lamestllama]

Slightly off topic

BobL I agree with your thoughts on "procedural or algorithmic" knowledge. In nearly every arena we see people taught to pass a test rather than taught to understand the fundamentals and thus have the basis for solving problems outside the scope of their teaching.

In particular regard to electricity I would say the nanny state approach in this country means that electricity may as well be magic for most people. They have no sense of anything to do with the subject because they are largely legislated away from getting any exposure. In NZ the government actually supplies the public information on how to DIY the electrical jobs they are permitted to perform themselves. I believe this increases the awareness of the dangers associated with electricity and lifts the awareness of society as a whole.

The $2 ammeter is probably the old fashioned solution now. It wouldn't be difficult to program a IOT device or bluetooth device to monitor your power usage keep statistics and report any anomalies audibly, visually or otherwise. Perhaps there is a market for such a device?

In respect to the fridge being connected to the internet is is just an example of the way the IOT will if we participate make us the product.

Eric

[Karl Robbers]

Slightly off topic by I occasionally wonder about a bunch of things related to electricity like how utterly clueless most people are about the dangers of electricity compared even dare I say it to motor vehicles, and why machines are not fitted with simple $2 ammeters.

Users of motor vehicles require require some training yet very little little is provided regards electrical safety training for the general public or for that matter even in the workplace. Instead we "nanny state" it and try and make everything as protected as possible. Vehicles will probably only every get to that level when they are driverless.

I taught 7 year of High school physics and the fact that only a few % of students do this subject to even a basic depth is just one of many problems. The other thing to remember is it is possible to "pass" high school physics, but completely fail the section on electricity.

Then I taught basic and advanced physics and electricity subjects at Uni for ~25 years and what I saw was the knowledge that students came in with was woeful to say the least and not much better when they graduated. I regularly conducted pre and post test using simple DC circuits ie globes and batteries and how much current is needed to kill some one. I have to say the results were very depressing. Even students that arrived with electrical and related trade certificates, some upgrading their qualifications to engineering degrees, had a very limited fundamental understanding of electricity. The most unusual students I taught were two 30 something ex-SAS specialists starting their engineering degrees. They had extensive training and field field in electrical circuits related to explosive devices but had a surprisingly poor understanding of electricity itself.

During my time at Uni I participated (ie I was a subject or participant) in a research project conducted by a PhD student on the depth of knowledge and understanding about electricity form primary school age through to fully experienced electrical engineers and how these people were taught about electricity. School and uni curricula were assessed in terms of the time spent and the way students were taught. The results were unsurprising, electricity occupies a very small portion of basic science curricula and like almost all subjects student were taught using only "models and algorithms" and students stick to these like glue when they should be moving up the ladder of fundamental understanding and we leave it to the students to make the leap to deep understanding and generalised cases. Often the exams might test generalised cases usually without teaching the students about it, and naturally this is where students generally poorest poorest at.

My experience in dealing with sparkies has been mixed. Some of them are fantastic - the 80 year old sparky at our mens shed is great, thorough, careful, and from the "sneaky" questions I ask him he really knows what he's doing. Some, I cannot for the life of me understand how they ever got a cert. Most sparkies (like most people) operate at what is called an "algorithmic" or "procedural" level because this how they are taught. EG Here are the steps to solve this problem - don't worry about understanding them, just remember them. These procedures are usually designed to keep them and the public as safe as possible. However, to cope with as many eventualities as possible, eventually all procedures/regulations/installation standards become complex, unwieldy and harder to remember and unfortunately simply cannot cover all possible situations. Unless a person has a deeper fundamental knowledge of the topic they may then get it wrong.

I reckon one of the main reasons for this is that less and less time is allocated to studying anything at tafe/uni and in particular hands on (lab/prac) time has been cut by the bean counters by about half.

As people get more and more life experience and life practice they will come across more cases and build their experience and knowledge base up but this is neither a fast or safe way to learn. An extreme case is bomb disposal where the ground rules can change on a daily basis and they have limited ways of learning other than by example and is why they have such high death rates.

So my ramble brings me back to where I started and that is electricity should be more prominent in school science and we should encourage more students to study electricity in general to a greater level and there should be more public education about about it. The odd ad on TV about staying away from fallen power lines is useful, but woefully inadequate.

Now lets get to the $2 ammeter.
It's mandatory that vehicles have speedometers so users should know how fast they are going and what limits to stick to but it's very rare to see a simple V/I indicator device fitted to an electrical appliance. I contend especially larger machinery should have a V/I meter fitted within easy operator view and a blurb in the manual to explain how to use the meter in relation to usage. Even the fact that is says what the V/I is at any given time would help users better appreciate what is a low current/load and what is a high current/load and the 240V is NOT always 240V etc.

I have an ammeter on all my 4HP machines, WW BS, compressor and Dust collector while for other machines and tools I have a short extension cord with a VI meter in the middle and find and find it really useful. Experienced users who already have a feel for machinery would not need it but I reckon newbies especially could benefit greatly while they get the feel of the machinery. One some machines running on VFD I sometimes monitor the current that way but usually the single line display is left on frequency which is where dual line display VFDs come in handy

On simpler/simpler appliances it does not even have to be a meter - it could be an indicator light like on a dash - thing goes orange or red - think about what this means. It could be your blades are blunt or you have another extra load. We're'e starting to see these load indicators on power tool batteries - why not have them for the tool itself

Instead of doing something useful like this we have fridges connected to the internet that tell you when to order more food - how arsed about its this?
Yes, initially the meters and indicators could create a some initial confusion but there would also be many useful learning opportunities come out of it.

Ramble over.
I wholeheartedly agree with your comments BobL. Everything is becoming dumbed down. Even when you buy consumer electrical gear they now come with an instruction book and a quick start guide. Most only read the quick start guide and as soon they get lights or noise they are content. We only want to learn what we see as enough.
I believe that we have created the dumbest generation ever. Why? Because there is unprecedented access to information via the internet yet the most common searches relate to , celebrities or game hacks. If we go back a few years, people knew why and how an engine ran, they knew about mechanical advantage and leverage, some actually had reasonable knowledge of electricity. Now even trades are dumbed down and knowledge is being lost. If we compare our path to that of Europeans or Asian nations, it is not hard to see why we are being left behind.

[lamestllama]

Could you please provide a reference for this oft-quoted statement? My copy of AS/NZ 3018-2001 'Electrical Installations - Domestic Installations' has on p62 a Table 6-1 "Guidance on the number of points per final subcircuit" which clearly sets out the circuit conditions for one, two, or three 15A socket outlets per circuit. For a common 2.5mm2 wired circuit protected by a 20A circuit breaker, two 15A outlets are allowed except when the wiring is completely surrounded by thermal insulation -Item(I). Three 15A outlets are permitted on a 25A circuit with the wire gauge dependant on the installation method used.

Chas.

When I access the SAI global website I find that AS/NZS 3018:2001 has in fact been withdrawn and according to its history tab I find :-

Obsolescent 2009-09-14
Amendment 1 see DR 02592 CP First published as AS/NZS 3018:1997.
Second edition 2001

The intent of this product was to distill out of AS/NZS 3000 all that was needed to do domestic wiring with it being obsolete I suppose it is back to finding your way through the 611 pages of AS/NZS 3000:2018.

If you look at table C9 p483 of AZ/NZS 3000:2018 You can see that the contribution of a 15A socket outlet is 12A when a 2.5mm^2 wired circuit is protected by a 20A breaker and since 2 x 12A = 24A is greater than 20A you cannot have two 15A outlets on that circuit.

[Commander_Keen]

The NZ argument is certainly not a straw man and I am surprised with your interest in electrical safety you are not already aware of the meticulous statistics kept by the Electrical Regulatory Authorities Council?

You can find the latest at http://www.erac.gov.au/images/downloads/ERAC%20-%20Electrial%20fatality%20benchmarking%202017-2018.pdf

For the last few years NZ has certainly had less deaths people per capita by reason of electrocution see Graphs 1.2 and 1.6 of the above document. To say "it's a safer proposition to have it within the scope of a professional" is clearly difficult to justify when the data collected by the regulatory authorities indicates otherwise. Perhaps if we had more decisions based on evidence we might see even better outcomes?

Very interesting insight, thanks for sharing. Particularly graph 1.6 showing the AUS/NZ breakdown per capita. The results for the past few years are supportive, however we can also view the results prior to that (2003-2009) where the results were opposite to your observation, notwithstanding the outlier in 2005). NZ does have a steeper regression line in the reducing number of deaths than Australia, so there is merit that something there is working.
One note in favor of neither side of the discussion is that overall, the sample size is not huge... so the swings and roundabouts of a death here or there can markedly change the figures. You can actually see how the NZ outlier of 1.0 deaths per million people in the 2005 sample brought about the crossover point in the line of regression.


As they say, there are lies, damn lies, and statistics, so here is what I'm picking out of it, which does challenge your analysis, but you are welcome to read it as you may, and your mileage may vary.


Some points of interest that I found:

The overview of electrical deaths in AUS and NZ combined:
40% of electrical deaths occurred in the workplace, compared to 60% in a non workplace setting. (Graph 1.8). Over this same sample period (2017-2018, graph 1.7), 20% were electrical workers (those licensed to do electrical work), 20% were workers, who were not licensed (ie on the job at the time of death), and the majority, 60%, were the general public.
Ie the majority of deaths were people not licensed, and not in a workplace at the time of death. Were they doing their own electrical work at the time? Were they renovating and put the sawz-all thru the mains cable? I guess the next level of data may shed some further light on this. Lack of education or knowledge increases the risk of death.
Looking more broadly, the same trend is seen in the combines AUS/NZ data set in graph 1.9, where the general public and non electrical worker deaths constitute greater than 50% of deaths from 2000-2017, so the trend is valid over the years.

In plain English, the risks are higher when you are not trained. Is this the call to action for better education? Maybe. Is it worth putting the multi-billion dollar training investment through schools? Is it worth the losses (read decimation) of a whole industry of tradespeople, sacrificed for the 20 or so deaths that we see per year?
...I'm no economist, but there is some morbid bastard out there who is crunching the data and knows the cost of these 20 lives, and sadly, it is less than the roll-out of an alternative.


The data- narrowed to Consumer installations (In the home):
Section 3 of the report shows fatalities involving consumer installations and equipment.
"Consumer installation" as per the document, is defined as the installation past the point of supply on the consumer side. ie what the home gamers may be working on- home wiring, changing GPO's, putting circular saws thru conductors etc.
Of this consumer installation, generally speaking, 'general public' deaths outnumber those of electrical professionals 2:1. (Refer graph 3.1). Is this indicative of the ignorance of the dangers in the home setting?
Within the consumer installation sub-set, once again (see graph 3.2), 2/3 (67%) of deaths are of a non-workplace nature. The remaining 1/3 would include electrical workers working on consumer installations (ie, fitting a new circuit, excavating on site, renovating etc). Once again, still a greater risk as a layman / general public member. There is the argument that consumer installations have a higher presence on non-workers - ie it's a home, not a workplace- but I think that goes without saying.
The most interesting part of it, for me at least, is Graph 3.3- showing that 67% of deaths occur as a result of misuse or interfering with equipment or wiring- as an example the thread title of 'modifying a power plug' on a welder for example.

[jack620]

Of this consumer installation, generally speaking, 'general public' deaths outnumber those of electrical professionals 2:1. (Refer graph 3.1). Is this indicative of the ignorance of the dangers in the home setting?


I doubt it. It more likely reflects the fact that there are many times more ‘general public’ than electrical professionals.

[BobL]

I doubt it. It more likely reflects the fact that there are many times more ‘general public’ than electrical professionals.

OHS authorities don't usually look at things this way.
They look at total deaths because that's what hits the news.

The other thing that should be taken into account is "exposure hours to task".
A good example of this is the somewhat blinkered focus on total motor vehicle deaths per annum, eg for a State, versus a more real statistic of "motor vehicle deaths per km drive" which has fallen dramatically due mainly to the improvements in motor vehicles.

The average DIY electrical exposure is going to be in the hours per year category compared to an electrical pro who might be on say 20 hours per week (1000 hours/yr) of direct exposure. If they had the same "exposure hours to task" as pros the numbers of DIY electrocutions would rise dramatically.

Studies of pro V DIY accident rates are very interesting.
In most machinery and tool related injuries there's not a lot of difference in accident rates per head per hour of exposure for even as something as simple as a chisel injury. There is a reduction is accident rates with age (as complete idiots will remove themselves from the cohort) but not as much as we might expect.

My take on this goes something like this.

The average DIY operator is guided by a mixture of ignorance (ie lack of training and experience), over hesitancy due to under confidence, and non-OHS DIY worplace ie fewer restrictions on how they can do things. The younger they they are the more bullet proof they believe themselves to be so tend to have less hesitancy offset to some degree by quicker reflexes. As DIYers age their hesitancy increases but so does over confidence and reflex time, while ignorance may not change.

The average pro should be trained (although sometimes I do wonder about this) have a suitable level of confidence, and operates in a OHS workplace restricted space. The older pros get one would assume they should approach a near zero accident rate but unfortunately they can also get too overconfident and more casual, and of course have slower reflexes. This is why even experienced pro operators still injure themselves and have accident rates that are higher than might be expected.

All this goes to show that, whether you are a DIY or a PRO you can never be too careful.

[Vernonv]

The average DIY electrical exposure is going to be in the hours per year category compared to an electrical pro who might be on say 20 hours per week (1000 hours/yr) of direct exposure. If they had the same "exposure hours to task" as pros the numbers of DIY electrocutions would rise dramatically.

Studies of pro V DIY accident rates are very interesting.
In most machinery and tool related injuries there's not a lot of difference in accident rates per head per hour of exposure for even as something as simple as a chisel injury. There is a reduction is accident rates with age (as complete idiots will remove themselves from the cohort) but not as much as we might expect.You are attributing all of the "general public" deaths to the "DIY electrician" category which I believe is a totally incorrect interpretation of the results.

These are just non-electricians (members of the general public) who get electrocuted - the definition of how and why they got electrocuted is unknown, but I would guess the bulk of the deaths would NOT be attributed to "DIY electrical work".

The hours of exposure is pretty irrelevant, as you can get electrocuted pretty much anywhere - we are constantly surrounded by electrical appliances, electrical wiring, overhead power lines, etc.

[BobL]

You are attributing all of the "general public" deaths to the "DIY electrician" category which I believe is a totally incorrect interpretation of the results.
These are just non-electricians (members of the general public) who get electrocuted - the definition of how and why they got electrocuted is unknown, but I would guess the bulk of the deaths would NOT be attributed to "DIY electrical work".

I never mentioned general public deaths I only was referring to DIYers who die directly while doing electrical work - these are know quantities. General public deaths arising from DIY electrical work or indirectly from things like house fires resulting from DIY electrical work is less well known but just makes the numbers worse


The hours of exposure is pretty irrelevant, as you can get electrocuted pretty much anywhere - we are constantly surrounded by electrical appliances, electrical wiring, overhead power lines, etc.

By hours of exposure I am referring only to hours spent working on electrical work.
If we let the average DIYer perform 40 hours a week of electrical work for a year how long do you think they would last compared to a qualified sparky.

[Vernonv]

I never mentioned general public deaths I only was referring to DIYers who die directly while doing electrical work - these are know quantities. Where? From the stats linked in this thread??? ... I must have missed them.

Also you were replying to a quote regarding "general public" deaths.

[Theberylbloke]

[/FONT]If you look at table C9 p483 of AZ/NZS 3000:2018 You can see that the contribution of a 15A socket outlet is 12A when a 2.5mm^2 wired circuit is protected by a 20A breaker and since 2 x 12A = 24A is greater than 20A you cannot have two 15A outlets on that circuit.

So this could be correct. It could be incorrect. I don't have a copy of the AS3000 in front of me. In many cases maximum demand calculations also come into play. Basically maximum demand allows for the fact that it is unlikely that all equipment on a circuit will be turned on and running and the same time. Thus while the first 15A GPO is rated at 12A, the second 15A GPO might only be rated at 6A for a total of 18 Amps. While a maximum emand calculation is all well and good a sparky on his game should also be asking the property owner if the two appliances connected to the two 15A GPOs are going to be run at the same time, and wire the circuit appropriately.

Having had a few days to gather my thoughts (that's a slow process!) on the original topic I think that a look at some history might be revealing.

Once upon a time there were only fuses for protecting electrical circuits. The fact that they have been phased out in favour of circuit breakers for domestic use tells you that maybe they only did a so so job. Two obvious problems with fuses.

1. Can't tell an earth fault from a phase to neutral short circuit and thus have to be rated for full circuit load.

2. Often able to hold current well beyond their rating for long periods of time.

Neither of these characteristics make them particularly safe. As an example of point 2. I witnessed a ground mount substation go up in flames because a 400 amp fuse was later found to be holding 495 amps of load for several hours a day. The heat generated was enough to cause the 400 amp rated switchpanel to go up in flames. A rather unplanned for event in a CBD carpark!

Now referring that back to our 10A vs 15A plugsand sockets :-

Flexible cables traditionally came in three ratings 7.5 Amps, 10 Amps & 15 Amps. Historically the cost of materials was a very major part of the installation cost as compared to today. I can offer the post above where a 50kW supply has been run to a shed (Way to go my man, high fives there etc.). 40 years ago that would not have happenned because the cost of the cables would have been such a large part of the total. It still would be expensive today however the labour costs are a much higher percentage of the overall job. This, back in the day, meant that circuits were usually only wired in the minimum sized cable required to do the job, a 10 amp rated cable for a 10 amp rated circuit. The consequences of plugging in a 15 amp rated appliance to such a circuit might be quite unpleasant given it was protected by fuses with the two issues listed above and given that the fuse wire could be upgraded by any layman to prevent "nuisance blowing" to say a lump of number 8 fencing wire! What could possibly go wrong??? :o

The simplist way to to prevent someone plugging in a 15 amp rated appliance to a 10 amp rated socket would be to make it physically impossible to fit them together i.e. a larger earth pin. Today we would call that an "engineering" control measure.

Fast forward to the present day, cable insulation has a higher temperature rating, we understand a bit more about what happens if you run cables through thermal insulation or bunch them together or run them in conduit or in parallel. We use circuit breakers with built in RCDs, so the question really becomes, is it ok to bypass an engineering control that may have outlived it's usefulness?

I'm going to say no. For two reasons.

Firstly, still plenty of 10 amp circuits run in unknown conductors protected by fuses loaded, supposedly, with 10 amp wire.:no:

Secondly, there is a risk, more likely with untrained laymen, of getting the polarity wrong and then failing to adequately test it afterwards. If the active and neutral are reversed then any earthed metal on an appliance may be at 240v. Plug such an appliance into a circuit protected by fuses and you have a death waiting to happen. I also would not guarantee an RCD to protect you, they fail and due to a lack on inspection it often goes unnoticed.

Interesting that in all the replies to this thread, this point has not been made as it is a far greater risk than starting a fire.


To sum up, If you don't have an inspection routine for your RCDs, if you don't know about polarity and how to use a megger for continuity testing, if you don't have the specific equipment required for adequate testing, then probably you should leave your 15 amp plug tops alone.


Disclaimer :- I'm a sparky. Sometimes I'm not on my game, sometimes I have three left feet all made of clay, the above is my opinion and constitues general advice only, do not rely on it, your life and the lives of your loved ones may be at risk, no reponsibilty accepted.


Cheers

The Beryl Bloke

[RustyArc]

If the active and neutral are reversed then any earthed metal on an appliance may be at 240v.

I don't quite understand this - there is no N-E connection inside earthed appliances. If there was, the RCD would always trip.

Or do you mean swapping active and earth?

[lamestllama]

So this could be correct. It could be incorrect. I don't have a copy of the AS3000 in front of me.


Well I do have a copy of AS3000:2018 in front of me and what I wrote is a correct report on the contents of table C9 of AS/NZS 3000:2018 and applies when the outlets are intended for general use . For instances where it could be more or less restrictive all you need do is look at note 9 to table C9.

377755


You said you had a few days to gather your thoughts. Why not check the only source that actually matters AS/NZS 3000:2018 in that time?

[lamestllama]

Very interesting insight, thanks for sharing..

You analysis is flawed on the basis of the definition of what an electrical worker is. In NZ a person who is not an electrician but is doing electrical work he is legally allowed to do is an electrical worker.

As always definitions are important in anything to do with statistics.

[BobL]

I don't quite understand this - there is no N-E connection inside earthed appliances. If there was, the RCD would always trip.

Or do you mean swapping active and earth?

Yep - I've seen a few.
One was beside bakelite GPO in a bedroom that probably only ever had been used to power a couple of bedside lamps and when the new homeowner plugged a small AC unit into it .......
Another was a DIY effort in a lean to laundry. Someone had brought power from a lighting circuit in the house roof cavity to the laundry and wired a single bakelite 3 pin socket and a separate switch to it. No earth wire installed either.
Seen a few home made extension cords with the A-N swapped and E-N swapped as well.
A recent fave was an HD expander board I found during rubbish pickup - probably fell off a truck. Someone had replaced the 3 pin with a 2 pin plug AND connected the A-N the wrong way around.
I haven't seen many since the newer white plastic electrical fittings with colour coded dots on the terminals have been around.

[Pumpkinate]

I can offer the post above where a 50kW supply has been run to a shed (Way to go my man, high fives there etc.).

That was me and I detect some sarcasm, although I'm not offended. Actually I think my super-sizing is sensible.... it cost maybe $1000 to upsize the cable (50m of cable was about $2k) and now my options are open. The house has a 63kVA supply. The shed is quite big too (the previous owner used to keep 3 school buses in it). If I see an ex-industrial machine with a 20kW motor or a 50kW induction furnace then it would only cost me a few hundred to connect them, and I'd likely get them cheap because few others in the hobby would have the power supply. Better than re-digging a 40+ metre trench!

I no longer let electricians make sizing decisions because in my experience they aren't good at it. By that I mean they tend to aim for the minimum required and not allow for later upgrades. An example was a few years ago I put in a swimming pool heat pump and the electrical work was around $4500. The heater worked OK although needed to run through the night in winter. Two years later I put in a 10kW solar system and it made sense to upsize the heater so it could do the job in daylight hours while the electricity was essentially free. The electrician returns and tells me the cable is not large enough, and that he is unable to pull a bigger one through the conduit so it would be a totally new trench etc at X thousand (I don't recall the amount). And I was thinking wouldn't it have been sensible to have oversized the original cable... isn't it obvious?

[GuzziJohn]

And I was thinking wouldn't it have been sensible to have oversized the original cable... isn't it obvious?

I guess in the never ending race to win jobs by quoting cheaper than the opposition it isn't always obvious.

[Karl Robbers]

When I built my house, I opted for 3 phase supply, (only $200 extra because somebody stuffed the quote up I think), initially a 25kVa transformer was installed, but then they saw some of the gear I had and upsized it to a 50kVa. Now I wish I had more as I acquired a 100CFM screw compressor that could draw 63Aof 3 phase!
Anyway, when the house was wired in by a qualified sparkie, he had to ring his mate as he had no idea how the set up the 3 phase bore pump and pressure switch. I really do wonder how good many sparkies are given the big mistakes I've seen over a period of time. It really seems that core knowledge is lacking and complacency is rife.

[Pumpkinate]

Now I wish I had more

My point exactly. Paying for a bigger cable is cheaper than redoing things.

[Commander_Keen]

Sure. I understand your angle, but I respectfully disagree. I do think that it is a poorly contrived definition and could be clearer, but I guess that not every policy clerk can knock it out of the park every day of the week, amiright? Peanuts, monkeys etc.

Fist the definitions from your source:
"Electrical worker”
A person who carries out electrical work and is licensed or authorized to do so.
“General public”
A person who is not doing any work as part of his or her employment or under a contract of work, or training at the time the incident occurs
“Non-electrical Worker”
A person who is in the process of carrying out their occupation and is not an electrical worker.
“Supply worker”
A person who is employed by a network operator.

There is some semantics to get our head around here:
The way I read it, is that the term 'Work' (as in 'electrical work), relates to the meaning of work as relating to effort in return for wages, salary etc.

The reason I say this, is given the context of the remaining classifications of people in the report- General public (not performing work as part of their employment), and Non Electrical Workers being those who are working (for income) but not an electrical worker by the preceeding definition. Interestingly, the remaining category- 'Supply worker' uses the word 'employed' which would make it all the more clearer if it was used consistently throughout the rest of the definitions (we also see instances of 'work', 'occupation', 'employed' and 'employment' in the definitions).


Yes, I agree that the 'licensed and authorized to do so' part applies to the general public in NZ, but note the sneaky use of the word 'AND':
"A person who carries out electrical work and is licensed or authorized to do so."
ie, you have to be employed as, AND licensed to (or not, if not applicable in your jursidiction), to be considered an electrical worker.

[Grahame Collins]

ADDED BY ADMIN


DISCLAIMER

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for advice offered by members posting replies
or asking questions regarding electrical work.
We strongly advise contacting a Licensed Tradesperson for all electrical work.

WARNING

Information supplied within posts is not to be considered as detailed formal instructions to complete a task.
Members following such information do so at their own risk

[lamestllama]

Sure. I understand your angle, but I respectfully disagree. I do think that it is a poorly contrived definition and could be clearer, but I guess that not every policy clerk can knock it out of the park every day of the week, amiright? Peanuts, monkeys etc.

Fist the definitions from your source:
"Electrical worker”
A person who carries out electrical work and is licensed or authorized to do so.
“General public”
A person who is not doing any work as part of his or her employment or under a contract of work, or training at the time the incident occurs
“Non-electrical Worker”
A person who is in the process of carrying out their occupation and is not an electrical worker.
“Supply worker”
A person who is employed by a network operator.

There is some semantics to get our head around here:
The way I read it, is that the term 'Work' (as in 'electrical work), relates to the meaning of work as relating to effort in return for wages, salary etc.


I disagree it is clear electrical work is work done to an electrical system (paid or unpaid). Otherwise the work NZ DIYers do to their electrical systems is not electrical work which is clearly a nonesense.



The reason I say this, is given the context of the remaining classifications of people in the report- General public (not performing work as part of their employment),


You gave the definition accurately then misunderstood it.
“General public”
A person who is not doing any work as part of his or her employment or under a contract of work, or training at the time the incident occurs

A member of the general public is simply someone who is not at work or being trained when they got electrocuted.


and Non Electrical Workers being those who are working (for income) but not an electrical worker by the preceeding definition.

Interestingly, the remaining category- 'Supply worker' uses the word 'employed' which would make it all the more clearer if it was used consistently throughout the rest of the definitions (we also see instances of 'work', 'occupation', 'employed' and 'employment' in the definitions).



You hinge your whole argument around the definition of supply worker.
“Supply worker”
A person who is employed by a network operator.

The reason why they mention employment here and not in electrical worker is because there are limits on what a NZ DIYer can do and that does not extend to the supply network. Further a dodgy licenced electrician doing work on the supply network without being authorised is not a supply worker.




Yes, I agree that the 'licensed and authorized to do so' part applies to the general public in NZ, but note the sneaky use of the word 'AND':
"A person who carries out electrical work and is licensed or authorized to do so."
ie, you have to be employed as, AND licensed to (or not, if not applicable in your jursidiction), to be considered an electrical worker.


The only people who are not licensed to do electrical work but are authorised to are NZ DIYers. The definition does not say they have to be employed that is your addition. If it where to exclude NZ DIYers then it would be unnecessary to include the subgroup that is unlicensed but authorised. Since the definition does clearly include those unlicensed but authorised then it can only be in an acknowledgement that electrical work is carried out by unlicensed NZ DIYers because there is no other group which is unlicensed yet authorised to do electrical work.

So when it comes to the stats the NZ DIYers are bunched in with the NZ licensed electricians and are doing quite well at not killing themselves.
If you took a moment to understand what electrical work these NZ DIYers can do and under what circumstances you would realise they have far more at stake for dodgy work than any licensed electrician (other than one who works on his own family house).

Your seem to think adding some extra conditions to these definitions is something you can do without asking the original researcher.

[Stustoys]

The simplist way to to prevent someone plugging in a 15 amp rated appliance to a 10 amp rated socket would be to make it physically impossible to fit them together i.e. a larger earth pin. Today we would call that an "engineering" control measure.

Yet(as RC stated in post 25) it in no way stops a 20 amp LOAD being connected to the 10 amp circuit. So nothing to do with the welder then, got something else?

What percentage of general population do you think give any thought to the load on the circuit before they plug their new toaster in? What percentage of them even know which GPO is on which circuit? Won't someone think about the children!



Firstly, still plenty of 10 amp circuits run in unknown conductors protected by fuses loaded, supposedly, with 10 amp wire.:no:

By that argument we shouldn't plug anything into anything or cross the road for that matter.



Secondly, there is a risk, more likely with untrained laymen, of getting the polarity wrong

So for safety sparkies should file the earth pin down as they cant be trusted to wire a plug either.:no:

As for warranties being void, this must be some of the great Australian back up and service I hear so much about. Would anyone care to postulate a fault in a welder that could happen with a 10amp plug that wouldn't have happened with a 15amp plug?

[Vernonv]

Would anyone care to postulate a fault in a welder that could happen with a 10amp plug that wouldn't have happened with a 15amp plug?I doubt there is any, however the user has effectively (illegally?) modified the equipment, and the manufacturer has a right to refuse a warranty claim on those grounds.

[.RC.]

This is more of an argument between people who like big government and those that like small government.

big government, less risk, more regulation, less freedoms.

small government, more risk, less regulations, more freedoms.

[lamestllama]

This is more of an argument between people who like big government and those that like small government.

big government, less risk, more regulation, less freedoms.

small government, more risk, less regulations, more freedoms.

This is about cartel behaviours combined with poor industry standards.

Look at the number of OTR Electrical Expiations Issued in six months in SA https://www.sa.gov.au/__data/assets/pdf_file/0018/401904/Regulation-Roundup-issue-41-Feb-2018.pdf while electricians are allowed to operate in a way that avoids transparency they will have no reason to lift their standards.

The fines are also laughable. The holder of a license should be held to a much higher standard than a member of the general public.

[Grahame Collins]

It is an argument of who can, who cannot and those who never, ever, under any circumstances should be allowed to even try.
377781

Would it surprise you to know that this photo was once posted in the Welding forum under the old WoodWork Forum.

The idiot poster believed he knew what he was doing.

He told us in the post that this was attached to a hot water system in Townsville. Worse still, it was in a block of flats.

My point here is electrical dicussion in this forum, about what should be legal, only serves to encourage people like this.

The electrical authorities use electrical licenses and permits to at least identify who are at the very least, capable. I fully support it.

This electrical licensing has been around for as long as I can remember and is not a recent development of big government.

[RustyArc]

That actually looks pretty ingenious - I assume the guy was after a higher-current circuit than available in his flat, so pretty clever to think of the HWS circuit - definitely an option to keep in mind.

As for compliance & safety, he hasn't modified the plug, and he's used cable ties.

[jack620]

And it looks like he painted the ends of the neutral wire black to prevent a wiring error. Clearly a safety conscious person. :)

[.RC.]

My point here is electrical dicussion in this forum, about what should be legal, only serves to encourage people like this.



How?

[Grahame Collins]

Not remotely funny. I am appalled that both of you choose to make light of something that serious.

Perhaps an electrician ( a real one) would like to point out the potential for those that genuinely don't know?

Grahame

[lamestllama]

It is an argument of who can, who cannot and those who never, ever, under any circumstances should be allowed to even try.
377781


You could argue that but then one could argue licensing is about protectionism for an industry. Every single one of us you included use devices not wired by electricians on a daily basis. These vary in size from laptops to machine tools. You might try to argue that they are built to a standard but frequently many of these items are dead on arrival proving that quality control is non existent. So it seems only electrical work actually performed in this country is the real thing that is special.



Would it surprise you to know that this photo was once posted in the Welding forum under the old WoodWork Forum.

The idiot poster believed he knew what he was doing.

He told us in the post that this was attached to a hot water system in Townsville. Worse still, it was in a block of flats.


Here is a page with a number of 6 monthly publications that give a list of faults that qualified electricians have been fined for in SA https://www.sa.gov.au/topics/energy-and-environment/electrical-gas-and-plumbing-safety-and-technical-regulation/about-the-otr/regulation-roundup. Unlike lawyers who are named and shamed on the Conduct Commissioners website, it is impossible to find out who these shonky operators are. So your single example really sinks into obscurity when the actual licensed electricians the people you have faith in are found actually guilty of dangerous acts every single month and are allowed to continue doing so and you or I can't tell if we are hiring one of those.



My point here is electrical dicussion in this forum, about what should be legal, only serves to encourage people like this.


That is very much like the argument about open source versus closed source when it come to security. It is always the open source operating systems that are trusted with the most critical tasks. The fact that our current laws don't allow us to adequately inspect our electricians work makes it very much a closed source type situation.




The electrical authorities use electrical licenses and permits to at least identify who are at the very least, capable. I fully support it.

Most of the crap bought from China particularly clone devices of such things as VFDs have never been certified and have never been touched by an electrician. Does your support for such regulation include abstinence from the use of such products?



This electrical licensing has been around for as long as I can remember and is not a recent development of big government.
I can assure you there was electricity before electrical licensing. Neither Tesla or Edison were license holders.

[jack620]

I am appalled that both of you choose to make light of something that serious.


Get off your high horse buddy. You're embarrassing yourself.

[Stustoys]

It is an argument of who can, who cannot and those who never, ever, under any circumstances should be allowed to even try.

And here was I thinking we were having a polite discussion as to how and why the world will end if a welder had a 10amp plug fitted. Seems to be light on answers so far.

You want to talk about experts? How about the aussie company that shipped 10000s(possibly 100000s) of items with a soldered earth connection? Now I maybe wrong but I believe earth connections must be a physical connection? Where is that electrician(a real one)when I need one? (now maybe it was a change of regs, but I don't believe so)

Perhaps an electrician ( a real one) would like to point out the potential for those that genuinely don't know?
Hey its your picture, your claim, maybe you should enlighten us?


I doubt there is any, however the user has effectively (illegally?) modified the equipment, and the manufacturer has a right to refuse a warranty claim on those grounds.

While I'm sure some manufacturers would say exactly that(we have had posts saying as much on this forum) I doubt that they can. Sure they maybe able to scare people off by threatening to inform Workcover etc, I'd hardly call that standing behind your product. I wonder if they are still trying to work out why that don't get a lot of repeat customers?
Imagine your shiny new "insert car manufacturer of your choice" kicked a rod out the side of the block leaving engine parts all over the road after a week, only to be told by said manufacturer "We noticed you've have fitted an air freshener to the rear-view mirror(illegally), I'm sorry but that's a modification you're not covered". Now don't get me wrong I wouldn't put it past them to try it on, but without the threat of "I'll get you buried in more paper work that you ever want to deal with that has nothing to do with the issue but lets us get out of paying up" I'm not so sure they would get far.

[.RC.]

It is an argument of who can, who cannot and those who never, ever, under any circumstances should be allowed to even try.
377781



I suppose the flip side is firstly what has he/she done. What are the circumstances surrounding it and was it dangerous.

Yes I can see what I believe to be the earth is not ideal. Was it done purely to test the machine, or was it a permanent installation?

What would happen tomorrow if all the state government's banded together and said unless you are a mechanic, you are totally forbidden from repairing any part of your car. This is to save lives from dodgy repairs to cars. Would the public simply say, yes that is fantastic and good? Some would I am sure, some certainly would not.

Is the above photo a result from our over zealous laws?

It is a bit like the current debate on pill testing. If people are going to do it regardless, is it better it is done safely, then trying to lock up and hide the knowledge with only a select few knowing it.

[Stustoys]

Is the above photo a result from our over zealous laws?
Warranty issues meant he could't cut the plug off ;)

[RustyArc]

Yes I can see what I believe to be the earth is not ideal. Was it done purely to test the machine, or was it a permanent installation?

Given the lack of gas or leads, it doesn't look like much welding was going on. It would be interesting to know the actual story behind the picture.

Also, if that HWS was on off-peak, that would have really screwed with his welding schedule.


EDIT: But thinking about it, off-peak would be cheap power, so maybe not so foolish.

[Theberylbloke]

That was me and I detect some sarcasm, although I'm not offended.

While I am occassionally sarcastic this was not one of those times. No sarcasm was intended. I really do think you have made a very good decision. I think anyone with the money to put in bigger wiring should do so for all the reasons you mention.

Most businesses are a bit gun shy of oversupplying and thus charging more. Sparky's are no different.

With regard to your pool heater, Solar and its consequences/advantages have taken awhile to percolate into everyone's mind. In this case the electrician did the job for the expected load at the time. Most people might not be keen on paying for a larger conduit and cable upfront than they need at the time, unless they think they will install extra load later.

Cheers

The Beryl Bloke

[Theberylbloke]

Yet(as RC stated in post 25) it in no way stops a 20 amp LOAD being connected to the 10 amp circuit.

Hi Stu,

Not sure I understand your comment here? My point was that by changing the physical size of the earth pin it prevents bigger loads being plugged into a circuit that may not be rated for it. i.e. an unmodified 15A single phase plug will not fit into a standard 10A GPO. My understanding of your comment is that that doesnt work???


What percentage of general population do you think give any thought to the load on the circuit before they plug their new toaster in? What percentage of them even know which GPO is on which circuit? Won't someone think about the children!

None at all. Which is why we have the rules and regulations we do.



By that argument we shouldn't plug anything into anything or cross the road for that matter.

The shaking head smiley at the end of my sentence iswhat passes for my sense of humour at work. You have to trust that the protective device will operate or, as you say, never cross the road either.



So for safety sparkies should file the earth pin down as they cant be trusted to wire a plug either.:no:

No. What I am saying is that there is a risk for everyone doing this work, sparkys included. That's why they should test their work. This is what they should have been trained to do. This is why they have meggers & multimeters.



Would anyone care to postulate a fault in a welder that could happen with a 10amp plug that wouldn't have happened with a 15amp plug?

Sure. How about a short circuit in the 10A plug that replaced the manufacturers 15A plug, or maybe the lack of an earth because the same person didn't make a good connection.

Cheers

The Beryl Bloke

[Theberylbloke]

This is more of an argument between people who like big government and those that like small government.

Hi .RC.,

While I understand that it can be seen that way. That is not really my point.

In truth I don't give a small furry rodents anus about whether people have a ticket or not. What I do care about is that the people doing the work understand the implications of what they are doing, know how to test what they have done and have the equipment to do those tests. The reality is that a ticket is just a piece of paper. I know ticketed sparkies who should find another line of work because they certianly don't have much of an idea.

Why do I care? People who carry out electrical work with inadequate knowledge of what they are doing put themselves, family and friends at risk. Shocks and death are not laughing matters.

Cheers

The Beryl Bloke

[Karl Robbers]

Hi .RC.,

While I understand that it can be seen that way. That is not really my point.

In truth I don't give a small furry rodents anus about whether people have a ticket or not. What I do care about is that the people doing the work understand the implications of what they are doing, know how to test what they have done and have the equipment to do those tests. The reality is that a ticket is just a piece of paper. I know ticketed sparkies who should find another line of work because they certianly don't have much of an idea.

Why do I care? People who carry out electrical work with inadequate knowledge of what they are doing put themselves, family and friends at risk. Shocks and death are not laughing matters.

Cheers

The Beryl Bloke
I don't think anyone could argue with these sentiments.

[Stustoys]

Not sure I understand your comment here? My point was that by changing the physical size of the earth pin it prevents bigger loads being plugged into a circuit that may not be rated for it. i.e. an unmodified 15A single phase plug will not fit into a standard 10A GPO. My understanding of your comment is that that doesnt work???

I said LOAD. In RC's example he could happily plug a LOAD of 250A onto a single fused circuit. Beer fridge on no beer fridge. So you're 15amp plug doesn't seem to do a lot to stop that.


None at all. Which is why we have the rules and regulations we do.

So they can plug 250A of load on a single circuit... .right?


The shaking head smiley at the end of my sentence iswhat passes for my sense of humour at work.
Then I dont get the joke.


You have to trust that the protective device will operate or, as you say, never cross the road either.
EXACTLY! and yet this thread kicked off(and much of what followed) is about some place where the wiring is substandard and incorrectly fused with some questionable insurance advice thrown in for good measure. The total LOAD is the issue, not where that load came from. So I'd say that's where the straw man is in this thread.

We then get this
as a home owner, he probably should have also maintained or at least had inspected his home for faults, But wait! He isn't qualified! he cant possibly be expected to do this. (I've even seen it argued he isnt even allowed to check fuses, them being part of the fixed wiring and all that. Though I cant comment on the truth of that. And just how would you truly test a fuse?)

How about the buzzing breaker on my main panel? sparky says its fine. I don't know, I know AC things can buzz, how much buzz is a bad thing?


No. What I am saying is that there is a risk for everyone doing this work, sparkys included. That's why they should test their work. This is what they should have been trained to do. This is why they have meggers & multimeters.
But filing the pin down removes that risk :no:


Sure. How about a short circuit in the 10A plug that replaced the manufacturers 15A plug, or maybe the lack of an earth because the same person didn't make a good connection.
A short? no problem your protective device will take care of that(see above). Though it would be a challenge to wire a 3 pin plug with a short I am sure someone has managed it.
No earth? welder is still gong to work just fine(NO I am not saying that is a good idea)
But is that the best you can do? That applies to all plugs. I am looking for a fault 'in the welder', the direct cause of which is the power flowing through a correctly* wired 10amp plug in lieu of a 15A plug .
*correctly in the physical sense not the regulatory sense.


Why do I care? People who carry out electrical work with inadequate knowledge of what they are doing put themselves, family and friends at risk. Shocks and death are not laughing matters.

Indeed, and it would seem NZ has found a better way of doing things. I'm sure all sparkys will be pushing for AU to follow suit. Yet 10 of 000s of faulty earths doesn't rate a comment.

How about the penalties for those qualified experts who are unlucky enough to get caught doing the wrong thing? $375, that wouldn't even remove the profit from many jobs. And it would seem you or I have no way of knowing whether that sparky we just called has been fined 5 times in the last year.

To quote a thread I read recently
"Now, guess what the fine is for having a dog in a national Park?

15 units - $2,378 finehttps://enoughgun.com/forum/images/smilies/new-.gif

So... Steal, ignore police, get and drive like a demon, play chicken with a train, give alcohol to kids, go on a drunk riot in public, leaving live cables exposed; that's all frowned upon.

But f*** me, don't let your dog out on a leash in a National Park to stretch their legs for 2 minutes. They take that s**t seriously! https://enoughgun.com/forum/images/smilies/icon_rolleyes.gif"
https://enoughgun.com/forum/viewtopic.php?f=70&t=8503

[jack620]

Boy, a lot of people getting hot under the collar about a plug.

[Vernonv]

While I'm sure some manufacturers would say exactly that(we have had posts saying as much on this forum) I doubt that they can. Sure they maybe able to scare people off by threatening to inform Workcover etc, I'd hardly call that standing behind your product. I wonder if they are still trying to work out why that don't get a lot of repeat customers?
I'm not saying that it is right, or that they will even do it ... I'm just saying that the CAN do it because the equipment was modified.


Imagine your shiny new "insert car manufacturer of your choice" kicked a rod out the side of the block leaving engine parts all over the road after a week, only to be told by said manufacturer "We noticed you've have fitted an air freshener to the rear-view mirror(illegally), I'm sorry but that's a modification you're not covered". Yeah that is a great parallel to cutting off and replacing a machines plug with a differently rated plug ... :rolleyes

[Stustoys]

I'm not saying that it is right, or that they will even do it ... I'm just saying that the CAN do it because the equipment was modified.
Sure, they CAN say whatever they like. Whether they in fact have a leg to stand on is another matter completely. I'd argue they don't, but lets just leave that to one side.
We are reliably informed that a least one service center does say exactly that. Their response when questioned about it isn't "take up it with consumer affairs" or "see you in small claims" or some such, given they believe they are within their rights to refuse said warranty claim. No, it's a threat to dob you into workcover. If you're happy to except that as "standing behind our product" then so be it.



Yeah that is a great parallel to cutting off and replacing a machines plug with a differently rated plug ... :rolleyes
Strange I thought it was a pretty good one.
Modification to a car that had no effect on the malfunction.
Modification to a welder that had no effect on the malfunction.(well until someone turns up with one).. :rolleyes

Hey I'm still waiting to hear about the hotwater welder.

[Grahame Collins]

Hey I'm still waiting to hear about the hotwater welder.

Feel free to search welding in the old WWF around 2nd Aug 2009 .That,s I saved the pic.

From what I remember the poster said he had just purchased it and lived in the flats and thought he could hook it up to the hotwater system.A system likely connected by copper pipes to the other flats bathrooms.

It does not take much of an imagination to work out what could happen if something went wrong.

Grahame

[Com_VC]

Wouldn't the breaker trip IF the welder did happen to draw too much current?

[Commander_Keen]

So they can plug 250A of load on a single circuit... .right?


Can I just interject and ask where the 250A load came from?
A large single phase welder can put up to 30A load on the workshop circuit (talking effective current here).
The welding circuit (between the electrode and earth clamp) could be up to or beyond 250A, depending on the unit. But since a welder is essentially a gearbox for electricity, we are talking about two separate loads here.

To put it in perspective, 250A would be equivalent of 100x 100W incandescent light globes on one circuit, which no electrician in his/her right mind would be seen installing, probably not even by a balaclava wearing apprentice doing an after-hours cashie.

[lamestllama]

Can I just interject and ask where the 250A load came from?
A large single phase welder can put up to 30A load on the workshop circuit (talking effective current here).
The welding circuit (between the electrode and earth clamp) could be up to or beyond 250A, depending on the unit. But since a welder is essentially a gearbox for electricity, we are talking about two separate loads here.

To put it in perspective, 250A would be equivalent of 100x 100W incandescent light globes on one circuit, which no electrician in his/her right mind would be seen installing, probably not even by a balaclava wearing apprentice doing an after-hours cashie.

To put it in perspective you need only do a little bit of arithmetic.

100 x 100W = 10KW
30A x 240V = 7.2KW

Plenty of electric hot water services, ovens and ducted refrigerative air conditioners are in that power range.

[jack620]

Modification to a car that had no effect on the malfunction.


Is an air freshener, mounted illegally or not, classed as a modification to a car? I highly doubt it.

[Stustoys]

Feel free to search welding in the old WWF around 2nd Aug 2009

I don't think I'll bother



It does not take much of an imagination to work out what could happen if something went wrong.
Oh I'd say it takes a fair amount of imagination. Please explain exactly what you think is going to happen.



Wouldn't the breaker trip IF the welder did happen to draw too much current?
Not on the planet we are talking about



Can I just interject and ask where the 250A load came from?

25 x 10 GPOs on one circuit. 25 fan heaters would do nicely. You aren't going to complain that its less likely than your little story are you?




To put it in perspective, 250A would be equivalent of 100x 100W incandescent light globes on one circuit,
You might want to check your maths.




which no electrician in his/her right mind would be seen installing, probably not even by a balaclava wearing apprentice doing an after-hours cashie.
And yet that seems to be just what RC has.(although I would think 25 was unusual)

[Stustoys]

Is an air freshener, mounted illegally or not, classed as a modification to a car? I highly doubt it.
Its mounted in a way that makes the car unroadworthy(or at least they used to be, I know they did change the details on drives view not to long ago but I don't know the exact details so MAYBE they are no longer illegal), I'd call that a modification. But if you'd like I'll change it to an illegally window tint.

[RustyArc]

To put it in perspective, 250A would be equivalent of 100x 100W incandescent light globes

While I pause and admire the maths exhibited here, talk of lots of incandescent lamps on a circuit does remind me of a shed project many years ago. I provided the electrical plan to the electrician show locations of GPOs and lights and switches and all that. The electrician used to be a council inspector, so I assumed not just well across his regs, but over and above most mortal sparkys.

The shed had 6 x 500W halogen floodlights spaced along its length. Being a lighting circuit he just went and put those on a 10A breaker. The lights worked. We pretty much never used them, except about once a year when we'd be working into the dark, loading a truck with a forklift while tractors and other vehicles were circulating in a fairly tight area - a moment of intense activity at the end of a long day where you really want that light to see what you're doing, and to keep people safe.

That's when we found out about the 10A breaker, because 6 x 500W lights draws 3,000W, or 12.5 Amps, and a 10A breaker will actually deliver that, without tripping, for quite a long time. We discovered, almost half an hour from memory. Then it'd trip and the workplace would plunge into darkness, and when it happened the first time, it was a moment where the workplace suddenly got extremely dangerous.

We then learned to expect it, and fast forward to a few years ago, replaced the lights with LED units.

That was the work of a qualified, licensed and highly experienced electrician, who happened to retire shortly after doing our job.

[Vernonv]

Strange I thought it was a pretty good one. Oh well, we all work to different standards I guess.


Modification to a car ...No you are adding something (of no consequence) ... you are not modifying, replacing, etc, and you are certainly not replacing a "rated" part with a lower rated replacement.

[Commander_Keen]

You might want to check your maths.


Granted, I had a brain fart on this one. Proof that you can't be awesome all the time, I guess.

[Stustoys]

Oh well, we all work to different standards I guess. Yes you could say that. :roll:


(of no consequence)
Yes that is the important part. I'm still waiting for the possible consequences "for the welder". If we can find one then the service centre will no longer need to use a work safe copout to avoid warranty obligations. They will be able to calmly explain "because the earth pin was 3mm narrower it caused all the caps to blow and fried everything".


you are certainly not replacing a "rated" part with a lower rated replacement.
No No, you forget, replacing a plug is something to risky for even a sparky to do without a lab full of test gear.
We modified the earth pin. The active and neutral are untouched.


Proof that you can't be awesome all the time, I guess.
Well we agree on something
So no problem with 25 fan heaters on one circuit then?

[.RC.]

I purchased a 200 amp inverter welder some years back. Came with a 15 amp plug.

Last year I purchased a second identical unit for someone else. This one came with a 10 amp plug.

[jack620]

You sure they were identical? Exactly the same electronics inside?