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  1. #1
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    Default AU version of ANSI Z49.1:2021 - Safety in Welding, Cutting, and Allied Processes

    What is the Australian equivalent of ANSI Z49.1:2021 - Safety in Welding, Cutting, and Allied Processes?

    I'm curious as to what the Australian standard has to say about grounding welding tables and/or work pieces.

    Thanks
    Jack

  2. #2
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    AS 1674 Safety in Welding and Allied Processes - 2007 ?

    according to Google


    It will cost you $234 or so to find out.

    The Standard is a low production run publication-that is why they cost a bundle.

    Grahame
    Last edited by Grahame Collins; 14th Jan 2022 at 10:09 PM. Reason: pore speling

  3. #3
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    Quote Originally Posted by Grahame Collins View Post
    AS 1674 Safety in Welding and Allied Processes - 2007 ?

    according to Google


    It will cost you $234 or so to find out.

    The Standard is a low production run publication-that is why they cost a bundle.

    Grahame
    Thanks Grahame. I did try looking for a cross reference on Google but must have used the wrong key-words.

    Most standards cost a lot - I guess that's why people don't get copies. As it's a safety standard, you'd think they'd make an effort to get it circulated. A PDF doesn't cost much to copy.

    Jack

  4. #4
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    I am not even sure if 2007 is the most recent update.

    These standards are compiled by a committee of professional level experts in their particular field.

    They come from industry and it takes a lot of meetings over a long time as the codes need checking with continual revisions with addendums.

    It costs money and that money can only be recouped through the limited volume sales. Codes are the basis upon which regulations and legislation are based.

    Thirty years back when I was studying for my welding supervisors and Welding Inspectors certificates I had had several hundred dollars invested in the codes.

    If there are few Welding supervisors are being trained today I suspect that the cost of the codes will be that will the cause.

    I had some help from by employer but not even they had the codes I needed.

    You might be lucky with possibly one of our members employed in industry and has access to the code.

    Grahame

  5. #5
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    I've got a few of the standards squirrelled away, but upon searching, turns out the soft copy PDF documents do in fact expire after a period of time...
    I too am interested to know, so I will see if I can find a source...

  6. #6
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    Right-o.
    The standard you seek is AS1674.2-2007 - Safety in welding and allied processes, Part 2 - Electrical


    The output (work) circuit is discussed in Section 4.2 - Welding circuit connections.
    This prefaces with 'the connection of the output leads is the responsibility of the welder, and power should be off when making connections.
    Also states welding output leads should be as short as practical, no longer than 9m, and in good repair. Also states that connections (ie fitting of replacment electrode holder, new earth clamp, new cable lugs and fittings etc) should be made by a 'competent person', ideally supervised or assessed by a licenced electrician . In my experience, these tasks are easier than playing with lego... Interestingly, if the output cables are permanently fixed... then design and fitting on this falls under AS3000 (standard for sparkies). Also goes into a bit of info on voltage drop, conductor size vs cable length etc.

    4.2.6 work lead and work conductor is the guts of your question, by the looks.
    Key paraphrased points are (with bold / underline being points that are worded to be unambiguous) :
    4.2.6 "The work lead should be soundly connected to the workpiece, as close to the welding as possible. Current Should notbe routed through uninsulated conductors such as the workpiece, the bench or bare metal strips."

    There is a section that talks on multiple power sources on one workpiece, and the need for electrical guidance on the current carrying capacity of the workpiece, in relation to the welding output, and duty cycle.

    Section 5.2 of this standard also talks on welding accessory equipment being inspected monthly by a competent person.

    Appendix 5- Secondary circuits, A5.1
    Talks about welding current thru a welder's body - namely as a result of being in contact with the job (eg installing a stick electrode, while also being in contact with the job which is connected to earth lead)

    Appendix 6 - stray currents

    In short, and my own words based on my reading of it - a poor earth connection on the output circuit can lead to increased welding circuit resistance, and subsequent raising of the voltage of the work piece. Meaning that current can find alternative paths to ground. Ideally this is NOT thru a human...This is probably the key for the idea put forward in 4.2.6 of this standard - connect earth lead TO the JOB, and as CLOSE AS POSSIBLE.

    'Stray currents' can cause electrical concern for wiring, lifting equipment, and even accelerate corrosion of pipelines... Something some peiople may not have considered, especially when working on larger structures.

    The Appendix B of the standard discusses some fatal incidents involving welding, one such example being a guy working in a boiler, soaked with sweat, who was leaning against the earthed structure (the welding circuit), while changing a stick electrode. Electrode tip touched his neck, welding current went thru him to earth, delivering approx 250mA for >0.5s - enough to kill him. I guess it's that easy to do...

  7. #7
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    For those boilermakers/welders who were involved in confined space welding.

    You learned very quickly that essential points were the
    efficiency of the work return connections ,
    the forced air supply,
    and having the mandated observer at the entry point to raise the alarm and shut down the welding machine and oxy acetylene set.

    No electric sheilds then.

    One had to stop and clean the moisture (sweat) between the cover and shield lenses just so the arc could be clearly seen.

    I have never forgotten having to strip down to the jocks and get greased to be able to exit a manhole opening.

    I could not work in a confined space after that one.

    Sorry about the thread drift but the above comments brought it all back.

    Grahame

  8. #8
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    Quote Originally Posted by Commander_Keen View Post
    Right-o.
    The standard you seek is AS1674.2-2007 - Safety in welding and allied processes, Part 2 - Electrical


    The output (work) circuit is discussed in Section 4.2 - Welding circuit connections.
    This prefaces with 'the connection of the output leads is the responsibility of the welder, and power should be off when making connections.
    Also states welding output leads should be as short as practical, no longer than 9m, and in good repair. Also states that connections (ie fitting of replacment electrode holder, new earth clamp, new cable lugs and fittings etc) should be made by a 'competent person', ideally supervised or assessed by a licenced electrician . In my experience, these tasks are easier than playing with lego... Interestingly, if the output cables are permanently fixed... then design and fitting on this falls under AS3000 (standard for sparkies). Also goes into a bit of info on voltage drop, conductor size vs cable length etc.

    4.2.6 work lead and work conductor is the guts of your question, by the looks.
    Key paraphrased points are (with bold / underline being points that are worded to be unambiguous) :
    4.2.6 "The work lead should be soundly connected to the workpiece, as close to the welding as possible. Current Should notbe routed through uninsulated conductors such as the workpiece, the bench or bare metal strips."

    There is a section that talks on multiple power sources on one workpiece, and the need for electrical guidance on the current carrying capacity of the workpiece, in relation to the welding output, and duty cycle.

    Section 5.2 of this standard also talks on welding accessory equipment being inspected monthly by a competent person.

    Appendix 5- Secondary circuits, A5.1
    Talks about welding current thru a welder's body - namely as a result of being in contact with the job (eg installing a stick electrode, while also being in contact with the job which is connected to earth lead)

    Appendix 6 - stray currents

    In short, and my own words based on my reading of it - a poor earth connection on the output circuit can lead to increased welding circuit resistance, and subsequent raising of the voltage of the work piece. Meaning that current can find alternative paths to ground. Ideally this is NOT thru a human...This is probably the key for the idea put forward in 4.2.6 of this standard - connect earth lead TO the JOB, and as CLOSE AS POSSIBLE.

    'Stray currents' can cause electrical concern for wiring, lifting equipment, and even accelerate corrosion of pipelines... Something some peiople may not have considered, especially when working on larger structures.

    The Appendix B of the standard discusses some fatal incidents involving welding, one such example being a guy working in a boiler, soaked with sweat, who was leaning against the earthed structure (the welding circuit), while changing a stick electrode. Electrode tip touched his neck, welding current went thru him to earth, delivering approx 250mA for >0.5s - enough to kill him. I guess it's that easy to do...
    Thanks for that - much obliged.

    I went on a hunt after Grahame gave me the Standard ID. AS1674.1 (fire) popped up almost immediately but AS1674.2 (electrical) was much harder to find. I found it in the end but it is glued to an individual. 2007 is the latest but there are some amendments.

    I was interested to find it because I wanted to know what it said about grounding the work and/or the welding table. There is a lot of rubbish on the Internet and through plagiarism, much of it is the same rubbish. Often the Earth (work) clamp is confused with the electrical (mains) Earth and it goes down hill from there.

    A grounded (bonded to ground) workpiece would help from a safety standpoint when, for example, an old, unmaintained, transformer type welder leaked mains voltage to the work leads. One would expect an earth leakage detector would trip before the operator was killed. In most other cases, a grounded workpiece is a safety liability. The danger being addressed here is electric shock from the mains via the welding circuit - not electric shock from the welding circuit itself.

    I would not ground a welding table for that purpose (I don't have any unmaintained welders).

    The thing is that for the Americans, ANSI Z49.1 requires that the welding table be grounded (unless etc) and here, AS1674.2 requires that the welding circuit be floating (not grounded).

    AS1674.2 is fairly straight forward in its requirements. ANSI Z49.1 is quite detailed covering the negative side effects of grounding the work.

    It needs to be borne in mind that some welding takes place in tall steel framed buildings where the building itself might form the work return path. ANSI Z49.1 was probably born in that environment.

    Jack
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    Quote Originally Posted by Jack Ryan View Post
    Thanks for that - much obliged.
    I'll let you know where to send my Christmas card .


    As I understand, It needs to be looked at as two distinct circuits- When you look at a welder - the input circuit (240V, 415V) and the output circuit (the welding torch side), are electrically isolated. Whether this is an inverter machine, or a transformer based architecture, the transformer is where this happens - eddy currents thru the windings etc etc but NOT electrically linked. So this is the interface between input and output. Work return lead (o utput side), is not the same as the input earth. Pretty sure the AUS standard going into this in the earlier parts of the standard (the bits I didn't go into depth of).

    Pro tip- if you look at the welding machine's data plate, there should be a basic schematic of the circuit showing two interlinked circles- indicating an output that is isolated from the mains.

    So like you said, for a maintained machine it should not be a problem- with no leakage between input and output. So as to how one would ensure that a leakage does not become a problem would be covered by a whole host of other standards and guidelines - ie monthly inspection of welding output connections, and any 'testing and tagging' of equipment on site, to check the input circuit side. On top of any AS 3000 sparky related stuff that is in place.


    Disclaimer- I'm not an electrician, so everything beyond this sentence could be 100% wrong... but as I understand it, IF the table was 'grounded' as you say (assuming you mean grounded to the same ground as the 240V / 3 phase green/yellow wire in the GPO's - ie same potential as the earth stake in the meter box) - then would this not put the welding table as a possible path to earth IF there is a failure in the Neutral wiring of the input circuit?
    I understand AU mains power (240/415V)has an MEN link - ie neutral and earth are bonded. So a fault in the neutral circuit back to the mains board will be able to find an alternate path to earth via the MEN. If least resistance in a failure was via a earthed welding table, this could lead to a potential shock?

    A TAFE site I know of has their welders gounded back into the GPO's - a ring terminal to the grounded metal case of the welder links back into the power point earth. Even for an institution as anal as they are, welding tables are not connected to electrical earth any further than the contact patch they make with the concrete floor...

  10. #10
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    Quote Originally Posted by Commander_Keen View Post
    As I understand, It needs to be looked at as two distinct circuits- When you look at a welder - the input circuit (240V, 415V) and the output circuit (the welding torch side), are electrically isolated. Whether this is an inverter machine, or a transformer based architecture, the transformer is where this happens - eddy currents thru the windings etc etc but NOT electrically linked. So this is the interface between input and output. Work return lead (o utput side), is not the same as the input earth. Pretty sure the AUS standard going into this in the earlier parts of the standard (the bits I didn't go into depth of).
    Yes, there are two circuits and the two should be isolated to several thousand volts. The input circuit - 230 volts single phase or higher plus an electrical ground that, in Australia and many other places, is bonded to neutral and the physical ground. It is isolated from the output circuit by, at least, a mains transformer. The output circuit includes the torch/electrode, the work lead and clamp and the work. Often the return path for the welding current also includes a welding table. The output circuit is isolated from both the mains circuit and the electrical ground.

    The Australian standard, AS1674.2, requires that this isolation be maintained. The American standard, ANSI Z49.1, requires that the welding circuit be connected to electrical ground.

    Pro tip- if you look at the welding machine's data plate, there should be a basic schematic of the circuit showing two interlinked circles- indicating an output that is isolated from the mains.
    And on modern welders, it can be seen that the isolation between the input (mains) circuit and the output (welding) circuit is increasing.

    So like you said, for a maintained machine it should not be a problem- with no leakage between input and output. So as to how one would ensure that a leakage does not become a problem would be covered by a whole host of other standards and guidelines - ie monthly inspection of welding output connections, and any 'testing and tagging' of equipment on site, to check the input circuit side. On top of any AS 3000 sparky related stuff that is in place.
    I think any danger at the output from the mains is more likely due to the breakdown of insulation often by mechanical means (vibration/rubbing) which is much more easily detected.

    Disclaimer- I'm not an electrician
    For the record, neither am I.


    as I understand it, IF the table was 'grounded' as you say (assuming you mean grounded to the same ground as the 240V / 3 phase green/yellow wire in the GPO's - ie same potential as the earth stake in the meter box) - then would this not put the welding table as a possible path to earth IF there is a failure in the Neutral wiring of the input circuit?
    I understand AU mains power (240/415V)has an MEN link - ie neutral and earth are bonded. So a fault in the neutral circuit back to the mains board will be able to find an alternate path to earth via the MEN. If least resistance in a failure was via a earthed welding table, this could lead to a potential shock?
    It certainly could

    A TAFE site I know of has their welders gounded back into the GPO's - a ring terminal to the grounded metal case of the welder links back into the power point earth.
    As far as I am aware, all welders that comply with Australian standards have their frame and case bonded to mains ground. What was the purpose of the additional grounding.

    (I haven't seen any double insulated welders but I'm sure they'll pop up eventually if they are not here already.)


    Even for an institution as anal as they are, welding tables are not connected to electrical earth any further than the contact patch they make with the concrete floor...
    And if they did, their site would not comply with the Australian standard.

    What I find sort of amusing, is that the Australian standard contradicts the American standard. I'll stick with the Australian standard.

    Regards
    Jack

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