PDA

View Full Version : Help me Rewire A Motor From Star To Delta and To Connect the VFD in Melbourne



thumbsucker
16th Jun 2015, 12:44 PM
Hi - I am restoring an 1962 Waldown Drill Press over in this thread (http://www.woodworkforums.com/showthread.php?t=195487).

I was advised to post in Metalworking as I am in need of some help from a forum member who is willing and able to rewire a 3 phase motor from Star To Delta and to connect a 240 volt to 400 volt Powtran Variable Frequency Drive for me.

I am located in Coburg Melbourne.

I am happy to reimburse you for your time and expenses.

My understanding of electrical things is rudimentary and I dare not do it myself.

If you are interested please PM me and lets see if we can work something out.

It is my understanding is to first find out if the motor can be rewired from star to delta.

To that end I have attached photos of the motor stator and the manual for the VFD in pdf.

The details on the motor plate reads:

Horsepower 0.75
RPM 1440
Volts 400
Amps 15
Rating Continues
Wind Star

350139


350140350141350142350144
350145350146350147350148
350150350151350152350153
350154350155350156350157
350158350143350149

Stustoys
16th Jun 2015, 01:44 PM
Hi,

Do you have a picture of the VSD nameplate or a link to the VSD you purchased?
I cant find any specs on a PI9000 that has single phase input.(though their web site says they are made, they don't list one)
I am assuming " to connect a 240 volt to 400 volt Powtran Variable Frequency Drive" is a misunderstand or typo on your part, if the VSD converted 200V to 400V you wouldn't need to convert the motor from star to delta.

Stuart

thumbsucker
16th Jun 2015, 03:01 PM
Hello Stuart the exact model is PI9130A 0R7G3.

I have attached another manual for the PI9130A 0R7G3.

350159

Attached is a photo of the nameplate. It has a typo on it. It should say Input AC 1PH 230 V NOT Input AC 3PH 230 V

350161

Stustoys
16th Jun 2015, 03:40 PM
Thanks.
Sorry to say thats not helping, that manual says the last 3 in the model number means "input voltage level 3:Three-phase 380V"
So two typos that disagree both with each other and with what you think it is :(
I guess it has to be one of the three ;)

If you're correct that it's single phase 230V input and 3 phase 400V output, you wont need to rewire the motor.

Maybe I'm missing something

Not much help sorry

Stuart

thumbsucker
16th Jun 2015, 04:22 PM
Okay Stuart - I think its time to send an email to Powtran to get clarification - this is what I am thinking of asking is there anything else I should ask and am I asking the right question/details?

--------------------------------------------------------------------------------
I am trying to find an electrician who can connect your PI9130A 0R7G3 to my motor and to the house. However I am getting confusing advice and I was hoping you can help.

I got your PI9130A 0R7G3 VFD.

I have a 3 phase motor:

Horsepower 0.75
RPM 1440
Volts 400
Amps 15
Rating Continues
Wind Star

And I have 10amp 240 volt electric wall socket in the workshop.

Questions:



Do I need to rewire the motor from star to delta to make it work with your VFD PI9130A 0R7G3?
Will the 10amp 240 volt electric wall socket supply enough power to run the FVD and the motor?
Can you confirm that the VFD PI9130A 0R7G3 is 1 phase input and 3 phase output, because the nameplate sticker on the FVD says Input AC 3PH 230 V. IS this this a typo?



--------------------------------------------------------------------------------

Stustoys
16th Jun 2015, 04:57 PM
Amps 1.5 <you left out the .

And I have 10amp 240 volt single phase electric wall socket in the workshop.

Questions:



Do I need to rewire the motor from star to delta to make it work with your VFD PI9130A 0R7G3?
Will the 10amp 240 volt single phase electric wall socket supply enough power to run the VFD and the motor?
Can you confirm that the VFD PI9130A 0R7G3 is single phase 230V input and 3 phase 400V output, because the nameplate sticker on the VFD says Input AC 3PH 230 V. IS this this a typo?



I'd attach a picture of the sticker to show that one of the numbers must be wrong(assuming I'm reading the manual correctly).

Good luck

Stuart

thumbsucker
16th Jun 2015, 05:08 PM
Thanks Stuart - Modified Email with photo of nameplate sent - I should hear back from them in the next few hours.

thumbsucker
16th Jun 2015, 05:52 PM
Got a responce - Less then 1 hour.
-----------------------------------------------------------------
#1:About the rewire issue ,it's depond on which connect mode is used for 400V voltage? we need the motor can work for 380±10%V AC voltage.
For example ,if your motor connect as star is used for 400V . just connect it as star . If not pls rewire it as delta connect mode .


#2: yes, 10amp 240 volt single phase electric wall socket supply enough power to run the VFD and the motor.


#3: and check with the production DEPT. the VFD is single phase 230V input and 3 phase 400V output, it is a typo, Sorry.


Anything I can help .pls tap my shoulder.


Best regards
Merlinda
-----------------------------------------------------------------

Stuart can you can sense of what she is saying and the what are the implications?

neksmerj
16th Jun 2015, 06:49 PM
Thumbsucker,

are you sure the name plate is a typo? Even the manual stipulates input as 230V three phase.

As far as I know, and Stu, there's only one VFD that inputs 240V single phase and outputs 415V three phase.

Stu and I know well as we paid dearly for this feature.

The VFD is a brand name, Teco, modified by Drives Direct in the UK.

http://www.drivesdirect.co.uk/

I could be wrong......

Ken

thumbsucker
16th Jun 2015, 06:54 PM
According to Powtran - VFD PI9130A 0R7G3 is a single phase 230V input and 3 phase 400V output - they say the nameplate is a typo.

I have sent a follow up email -

-----------------------
Hello Merlinda

Is it also a typo in the manual PI9000英文说明书 V14.0 20140808EJ.pdf page 7. Were the OR7G3 is a 3- phase 380V Input?


http://www.woodworkforums.com/attachment.php?attachmentid=350191&stc=1

I assume this is my model VFD that PI9130A 0R7G3.

If it is not can you direct me to the page in the PI9000英文说明书 V14.0 20140808EJ.pdf that states the phase input for VFD PI9130A 0R7G3.?
-----------------------

If this ends up that I have ended up with a useless VFD then I am going be very at some folks who who assured me that this VFD was the right choice. And I will be $200 in the hole. It would have been simpler to sell the two three phase motors I have and buy a good single phase motor as I did with my bandsaw. However I am learning, and maybe with your help we might find a way out of this confusing mess. :depressed:

Thanks for link to the Drives Direct - the cost is double of Powtran. Have you found them good? Are they Chinese made or other?

neksmerj
16th Jun 2015, 07:31 PM
Thumbsucker,

Can I be cheeky and ask approx how much your VDF cost?

Looks like you have what you want there.

Ken

thumbsucker
16th Jun 2015, 07:39 PM
I bought it direct from Powtran in China it came to $199 including postage, took 3 days to arrive. They seem very helpful and responsive to my questions even if it is clear that their English is not 100%. There was a cheaper option on eBay for $140 something but Powtran came recommended, due to build quality and direct support from the company.


Thumbsucker,

Can I be cheeky and ask approx how much your VDF cost?

Looks like you have what you want there.

Ken

thumbsucker
16th Jun 2015, 07:53 PM
Joy!


The model you mentioned in the manual is our standard model. (3- pahse 380±10% Input.), It is not a typo.

for your requirement, We modified the software parameters and some hardwares of the power board. and make it as: 230v single pahse input and 400V three phase output.


Do you still have some problem for the connecting ?


Any further info, you can mail me or call our engineer Kevin by : 86-755-29630738


Best regards,

If this is true then they manufactured a VFD just for my specification - that would be impressive.

So what is our next move?

Stustoys
16th Jun 2015, 08:00 PM
HI Ken,

I'm guessing about $200 lol

Hi TS,

Can't say I understand Marlinda's answers well enough to be sure of anything, but she sure seems to be saying 240V single input - 400V output.

As for the implications
As long as it is rated for 240V single phase input you'll be able to use it. Its just a question of whether the star point needs digging out or not, 400V output then No, 240V output then YES.
From the quick look at the manual it seems to be a senorless vector drive? you'd pay more for one of those than a normal drive.


Stuart

Stustoys
16th Jun 2015, 08:21 PM
Well that would appear to be good news indeed

So what is our next move?
Well I guess there is only one thing left to do, get your sparky to wire it up and try it.

Will be interesting to hear the results.
If its only 230V output it will still run just at reduced power.

Stuart

thumbsucker
16th Jun 2015, 08:51 PM
Well this returns us to the beginning.

Powtran is saying that I can just keep the motor in Star and connect the VFD in 400V mode.

Now the question is what is 400V mode?

I assume it is about were the wires are connected inside the VFD?


#1:About the rewire issue ,it's depond on which connect mode is used for 400V voltage? we need the motor can work for 380±10%V AC voltage.
For example ,if your motor connect as star is used for 400V . just connect it as star . If not pls rewire it as delta connect mode .

Getting an electrician has been problematic most do not want to touch this kind of stuff. I found one but he seems to be in the dark about the details as he only did one VFD years ago.

cba_melbourne
16th Jun 2015, 08:54 PM
0R7G3 means it is a 3 phase 380V input and 3x 380V output
0R7G2 would mean its a 3 phase 220V input and 3x 220V output (which must be derated if used as 1ph 220V input!!)
0R7G1 would mean it is a 1 phase 220V input and 3x220V output (no derating required for 1ph 220V input)

Personally, I do think it is unlikely there are TWO TYPOS on that nameplate. Either it is an 0R7G2, or there would have to be two typos.

If it is an 0R7G2, the output voltage is 3x220V. A VFD with up-converter (a dual stage inverter) with 220V input and 380V output would cost CONSIDERABLY more $$$.

I would return it for a refund. Let THEM sort out THEIR typos first.

NCArcher
16th Jun 2015, 08:56 PM
Hi TS,
It looks like Powtran have made a one off VSD and at a great price. I will be interested to see how it performs. I have some experience with Powtran and they have always been helpful and responded to emails promptly. I believe their VFD's to be great value.

Put that motor back together, wire it up and see what happens.

thumbsucker
16th Jun 2015, 09:28 PM
NCArcher - has kindly offered to walk me through the wiring up of the Motor and the VFD via correspondence. I will post back as we progress.

CBA - the manual should just be ignored - it has nothing to do with my custom VFD.

Jayson
16th Jun 2015, 09:58 PM
are you sure the name plate is a typo? Even the manual stipulates input as 230V three phase.

As far as I know, and Stu, there's only one VFD that inputs 240V single phase and outputs 415V three phase.

Stu and I know well as we paid dearly for this feature.

The VFD is a brand name, Teco, modified by Drives Direct in the UK.

http://www.drivesdirect.co.uk/

I could be wrong......

Ken

I have a 5.5 KW Huanyang VFD that takes 240 single phase in and outputs about 415 3 phase, purchased for about $500 12 months ago so there are others out there, a 750 watt unit with the same features was about $200 at the time.

neksmerj
16th Jun 2015, 10:17 PM
Hi Jayson,

Well it's good to know there are other VFD's out there with 240V single phase input, 415V three phase output.

I'm not sure where you would find 240V three phase, anyway.

When I bought my unit several years ago, it was in excess of $550 including a remote pendant, so I guess we are about line ball.
And that was after a fight to have the UK VAT deducted. What a drama that was.

Ken

camoz
17th Jun 2015, 12:35 AM
TS,

Glad you have managed to get some answers, and perhaps good news. I'm definately tuning into this post to see how you get on. I had not realised a 240v single phase to 415v 3phase VFD was available at that sort of price. Glad NCArcher is going to help you through the process of setting it up (:2tsup: to him for the offer to help out).

Please do let us know how things go, and if it works out, would it be possible to get contact details for them, as I may go this way with my lathe.

Cheers,

Camo

cba_melbourne
17th Jun 2015, 12:36 AM
......

CBA - the manual should just be ignored - it has nothing to do with my custom VFD.

I think the VFD you have there is a normal 400V in 0-400V out VFD - but it has beed modified not to trip if the input voltage is 230V+/-10%. Most 400V VFD would trip if the input voltage drops under the 380V-10% mark.

What this means is that you can use it with 240V input to drive a 240V motor. There is no way this VFD can increase the input voltage above the output voltage.

If you hook it up to 240V single phase, you have to derate it according to the manual.

If you hook it up to a 380 or 400V motor, it will work. The motor will run. But it will never deliver its nameplate rating.

Chris

eskimo
17th Jun 2015, 09:28 AM
I have a 5.5 KW Huanyang VFD that takes 240 single phase in and outputs about 415 3 phase, purchased for about $500 12 months ago so there are others out there, a 750 watt unit with the same features was about $200 at the time.

what makes you say it delivers 415V?
a delta wound motor is still 3 phase but not 415V..its 240V 3 Ph

BobL
17th Jun 2015, 10:24 AM
what makes you say it delivers 415V?
a delta wound motor is still 3 phase but not 415V..its 240V 3 Ph

The connections and the V are not necessarily related.
I have two motors in my shed that are 415V delta, one is from a compressor and one is from a pump.
They still run on 240 V 3P but at half power and cannot be converted to run at full power on 240 3Ph.
Have yet to see a 240V 3P star connected but I suppose it is possible.

Stustoys
17th Jun 2015, 01:05 PM
There is no way this VFD can increase the input voltage above the output voltage.

Agreed ;)


what makes you say it delivers 415V?
a delta wound motor is still 3 phase but not 415V..its 240V 3 Ph
I believe most(?) motors above 5hp are star/start delta/run. Or 415V delta if you like.
This doesn't mean the VSD is suppling 415V I have no idea(truth is I haven't even checked my own VSD, though even without testing in any real sense, its pretty clean when you are running a 415V connected motor on 240V)

Stuart

p.s... I think I just said what Bobl did.... again lol


Have yet to see a 240V 3P star connected but I suppose it is possible.

cba_melbourne
17th Jun 2015, 02:53 PM
There is no VFD manufactured for a single country. It would not be commercially viable. VFD's are invariably made for the world market. That is why manufacturers speak od 100V class, 200V class, and 400V class VFD's (there are higher classes too, but irrelevant here).

Take a single phase 100V VFD, it will work in Japan on their 100V home supply, it will work in the USA on their 110 and 120V supplies, and many other countries in South America and Canada. These VFD's have a voltage doubler input stage, so they can output twice their input voltage and drive a 200V 3ph motor. But they only make these as low HP units, so their input current do not overload a 100V home power outlet.

Take a single phase 200V class VFD, it can run from a wide range of input voltages, typically 200-240V +/-10% (that is 180V to 264V). It will work in Japan on their 200V, it will work in the USA on their 220V (this is 2 times 110V out of phase by 180 degrees from a center tapped roadside transformer, as supplied to some homes over there), it will run in Europe on their 230V, and it will run in Australia on our 240V. And in many other countries too, including Russia and China and India. Think about it, the manufacturer has to make only one single model, and it can be sold all over the world. But the output voltage will never be greater than the input voltage. The VFD can however limit its maximum output voltage to any desired value (from 0 up to its input voltage).

A three phase 400V class VFD will work from 380V to 500V +/-10% input voltage (that is from 342V to 550V), making it again suitable for worlwide use. Its output voltage can again not exceed its input voltage, but it can limit its maximum output voltage to any value.


A similar trend to standardisation can be seen with motors, but motors cannot be made with voltage ranges as wide as VFD's. Motors can be hooked up to a VFD either in star or delta, both will work equally well provided the voltage matches the VFD output. Modern small HP motors are designed with a wide voltage range. A 230V motor will work perfectly well on a VFD with 220 or 240V output. A motor made to run in Japan on 200V will not be happy if run at 240V - it would burn out - it will be necessary to limit the VFD output voltage (simply by setting a parameter in the VFD software). Older motors do not have such wide voltage ranges, and sometimes they cannot be easily hooked up in star because the star point is not wired into the junction box. A motor can however always be run at a lower than its nameplate voltage, it just will not deliver its rated horsepower.


Edit: I am not aware of one single 200V class VFD on the market capable of providing a higher output voltage than its input voltage. There is no mass market for such a VFD, like there is in North America for 100V input 200V output VFD's. Over there, all small 3-phase motors are 220V and most homes only have 110V. In the rest of the world, nearly all small motors can be wired for 230 and 400V, so a 200V class VFD can drive them. And for the few old motors that cannot be hooked up either star or delta the market is too small to make a profit. It is possible for such VFD to be made on order.... for extra money, and not just one off but there would be a minimum order.

kwijibo99
17th Jun 2015, 03:58 PM
G'day thumbsucker,
If after the dust settles it turns out you need to convert your star wound motor to delta and it turns out too difficult to do via remote assistance from NC Archer you are welcome to call around and I can assist or do it for you.
I'm just up the road in Fawkner and have done a couple of these conversions for my own machines (including a Waldown drill press) so just sing out if I can help.
I accept all forms of beer, foreign or domestic as payment.
Cheers,
Greg.

thumbsucker
17th Jun 2015, 04:51 PM
Greg - thank you for the offer, if I cannot get it up and running by the end of the week, I will take you up on the offer.

I am not overly concerned with the technicalities. As long as my VFD allows me to run my 3 Phase motor, even at reduced power I will be happy as long as it performs for my needs. I am strictly a wood worker and have no need to drill metal. So even if I only get 1/2 Horsepower from my 3/4 Horsepower machine then I will be :U.

thorens
17th Jun 2015, 06:47 PM
There is no VFD manufactured for a single country. It would not be commercially viable. VFD's are invariably made for the world market. That is why manufacturers speak od 100V class, 200V class, and 400V class VFD's (there are higher classes too, but irrelevant here).

Take a single phase 100V VFD, it will work in Japan on their 100V home supply, it will work in the USA on their 110 and 120V supplies, and many other countries in South America and Canada. These VFD's have a voltage doubler input stage, so they can output twice their input voltage and drive a 200V 3ph motor. But they only make these as low HP units, so their input current do not overload a 100V home power outlet.

Take a single phase 200V class VFD, it can run from a wide range of input voltages, typically 200-240V +/-10% (that is 180V to 264V). It will work in Japan on their 200V, it will work in the USA on their 220V (this is 2 times 110V out of phase by 180 degrees from a center tapped roadside transformer, as supplied to some homes over there), it will run in Europe on their 230V, and it will run in Australia on our 240V. And in many other countries too, including Russia and China and India. Think about it, the manufacturer has to make only one single model, and it can be sold all over the world. But the output voltage will never be greater than the input voltage. The VFD can however limit its maximum output voltage to any desired value (from 0 up to its input voltage).

A three phase 400V class VFD will work from 380V to 500V +/-10% input voltage (that is from 342V to 550V), making it again suitable for worlwide use. Its output voltage can again not exceed its input voltage, but it can limit its maximum output voltage to any value.


A similar trend to standardisation can be seen with motors, but motors cannot be made with voltage ranges as wide as VFD's. Motors can be hooked up to a VFD either in star or delta, both will work equally well provided the voltage matches the VFD output. Modern small HP motors are designed with a wide voltage range. A 230V motor will work perfectly well on a VFD with 220 or 240V output. A motor made to run in Japan on 200V will not be happy if run at 240V - it would burn out - it will be necessary to limit the VFD output voltage (simply by setting a parameter in the VFD software). Older motors do not have such wide voltage ranges, and sometimes they cannot be easily hooked up in star because the star point is not wired into the junction box. A motor can however always be run at a lower than its nameplate voltage, it just will not deliver its rated horsepower.


Edit: I am not aware of one single 200V class VFD on the market capable of providing a higher output voltage than its input voltage. There is no mass market for such a VFD, like there is in North America for 100V input 200V output VFD's. Over there, all small 3-phase motors are 220V and most homes only have 110V. In the rest of the world, nearly all small motors can be wired for 230 and 400V, so a 200V class VFD can drive them. And for the few old motors that cannot be hooked up either star or delta the market is too small to make a profit. It is possible for such VFD to be made on order.... for extra money, and not just one off but there would be a minimum order.


I think there is a VFD on the market that not come from China that is 240v in and 415v out 3 phase . it come from UK

Peter

Jayson
17th Jun 2015, 06:52 PM
Just checked and it looks like I've been duped... Oh well...

350251350252

Chris Parks
17th Jun 2015, 09:44 PM
Just checked and it looks like I've been duped... Oh well...

350251350252

Stand by, I have contacts at Powtran. I will send them an email now and see what the reaction is.

Jayson
17th Jun 2015, 10:07 PM
Hi Chris,

Mine wasn't from Powtran. It is a Huanyang VFD

Chris Parks
17th Jun 2015, 10:13 PM
No worries.

Vernonv
18th Jun 2015, 12:57 PM
Just checked and it looks like I've been duped... Oh well... Maybe it's just an issue with your multimeter? Are you running it at over/around 100hz?

cba_melbourne
18th Jun 2015, 03:26 PM
Just checked and it looks like I've been duped... Oh well...

350251350252

But you cannot measure VFD output voltage with a digital multimeter. Even if that multimeter was a true RMS tye, it would just show meaningless garbage figures, due to its limited bandwidth and the RF noise created by the VFD. The VFD output is a non-sinusoidal, pulse width modulated voltage of several kHz frequency. That meter you have there may show a voltage easily 50% higher than it is in reality. To measure VFD output voltage you need an oscilloscope, or a very specialized digital multimeter. Or in a pinch you can use an old analog multimeter, but it has to be one with very low Ohm per Volt impedance (less thn 20 KOhm/Volt) else it will not be much better than a digital multimeter. If you have an oscilloscope, that would be your best option. If you are not into electronics or do not have a mate that is and do not want to spend 1k$+ on suitable measuring equipment, it is fair to say that the output voltage of a VFD cannot be measured at all.

What you could measure with that multimeter you have is the DC bus voltage, and that would be about 1.41 times the input voltage. But again, if you are not into power electronics it may be a bad idea to try this, as the bus voltage would have to be accessed inside the VFD. One false move and it starts getting life threatening. Not long ago we had a suicide candidate guy that was testing the board of a DC variable speed controller on a steel benchtop..... most fortunately he only cooked the board..... and not himself.

BobL
18th Jun 2015, 06:54 PM
But you cannot measure VFD output voltage with a digital multimeter. Even if that multimeter was a true RMS tye, it would just show meaningless garbage figures, due to its limited bandwidth and the RF noise created by the VFD. The VFD output is a non-sinusoidal, pulse width modulated voltage of several kHz frequency. That meter you have there may show a voltage easily 50% higher than it is in reality. To measure VFD output voltage you need an oscilloscope, or a very specialized digital multimeter. Or in a pinch you can use an old analog multimeter, but it has to be one with very low Ohm per Volt impedance (less thn 20 KOhm/Volt) else it will not be much better than a digital multimeter. If you have an oscilloscope, that would be your best option. If you are not into electronics or do not have a mate that is and do not want to spend 1k$+ on suitable measuring equipment, it is fair to say that the output voltage of a VFD cannot be measured at all.

Many CRO's don't have sufficient V/division to reach mains power V's levels.

cba_melbourne
18th Jun 2015, 08:20 PM
Many CRO's don't have sufficient V/division to reach mains power V's levels.

Bob, that is correct. That is why they make 10:1 and 100:1 and 1000:1 probes to go with scopes.

If you take a scope with a maximum of 5V/division, and add a 10:1 probe, it becomes 50V per division. With 10 divisionss on the screen, you can display a full 250V sine curve, going 250V positive to 250V negative. If you add a 100:1 probe, each division becomes 500V. There are switchable probes too, so you do not have to buy 2 or 3 probes.

Be careful with scopes that do not have fully insulated input stages when measuring VFD outputs, you may end up with line voltage on the scope chassis. Fully insulated handheld scopes are the ideal tool to work on VFD's.

cba_melbourne
18th Jun 2015, 08:29 PM
Many CRO's don't have sufficient V/division to reach mains power V's levels.

Bob, that is correct. That is why they make 10:1 and 100:1 and 1000:1 probes to go with scopes.

If you take a scope with a maximum of 5V/division, and add a 10:1 probe, it becomes 50V per division. With 10 divisionss on the screen, you can display a full 250V sine curve, going 250V positive to 250V negative. If you add a 100:1 probe, each division becomes 500V. There are switchable probes too, so you do not have to buy 2 probes - like this one, the longish black slider selects between 1:1 and 10:1
350382

Be careful with scopes that do not have fully insulated input stages when measuring VFD outputs, you may end up with line voltage on the scope chassis. Fully insulated handheld scopes are the ideal tool to work on VFD's.

Jayson
18th Jun 2015, 08:35 PM
I just borrowed a mates new DSO and went to measure the voltage, turned on the VFD, hooked up the little alligator clip to one of the phases and boom, flash, #$#@....

Pointing my friend to this thread so he can see it wasn't my fault......

Lots of information has been given in this thread that could result in the above.

So, lets just leave it at no VFD will give 380/415 output from 240 in, this seems to be the consensus from those that know.

Going out to the shed to use my lathe...

RustyArc
18th Jun 2015, 09:00 PM
Be careful with scopes that do not have fully insulated input stages when measuring VFD outputs, you may end up with line voltage on the scope chassis. Fully insulated handheld scopes are the ideal tool to work on VFD's.

Honestly, you'd want to be pretty brave/competent to go scoping the output of a VFD - for starters, the output is probably floating, meaning you really want to differential probe across 2 scope channels (or use a differential probe), and even with 10:1 or 100:1 you really want a decent Cat rating on the probes - having a high divider ratio on a probe does *not* mean it's therefore designed for high voltages.

I'd expect measuring the voltage with the load attached would go some way towards dealing with the harmonic content. Also I think the DC bus is sometimes readily available for connection to a braking resistor? Again, though, I'd be really careful measuring high DC voltages with a DVM that's not properly designed for high-energy sources.

RustyArc
18th Jun 2015, 09:04 PM
So, lets just leave it at no VFD will give 380/415 output from 240 in, this seems to be the consensus from those that know.

While I've never met one, there's no reason they can't exist, you'd just need an intermediate inverter stage (i.e. a DC-DC converter) to boost the DC bus voltage.

Stustoys
18th Jun 2015, 09:18 PM
Honestly, you'd want to be pretty brave/competent
I have a 20V/Div CRO with 10 times CAT 1 500V probes but I'm pretty sure it doesn't have isolated inputs and I'm neither brave or competent :D
I assume 500v wouldn't really be considered good enough?
If I had an isolation transformer large enough to run the VSD on would that remove the isolated input problem?
Not that I have any plans to do such ATM just interested.



So, lets just leave it at no VFD will give 380/415 output from 240 in, this seems to be the consensus from those that know.


Want to bet? :p

Stuart

Stustoys
18th Jun 2015, 09:25 PM
While I've never met one, there's no reason they can't exist, you'd just need an intermediate inverter stage (i.e. a DC-DC converter) to boost the DC bus voltage.
I believe(though cant recall where I got the info from) that my VSD uses a voltage doubler* on the mains side then uses a standard 415V VSD.

As I said earlier but have never put a meter on it...... but I have run the same motor on a 240V in/out VSD an you can certainly tell the difference.

Stuart

*If I recall correctly the person that supplied said info was not all that impressed with the design of said doubler, but so far it seems to be working just fine.

cba_melbourne
18th Jun 2015, 10:21 PM
I believe(though cant recall where I got the info from) that my VSD uses a voltage doubler* on the mains side then uses a standard 415V VSD.

As I said earlier but have never put a meter on it...... but I have run the same motor on a 240V in/out VSD an you can certainly tell the difference.

Stuart

*If I recall correctly the person that supplied said info was not all that impressed with the design of said doubler, but so far it seems to be working just fine.


Drives Direct in the UK sells a range of 240V to 415V inverters. They seem to use a voltage doubler at the input stage. Drives direct must have had them manufactured on order, as no one else seems to sell them. Here is a video that shows the insides. I think it is an earlier model, not exactly the ones they sell now:

https://www.youtube.com/watch?v=VnLRhEHVLxA

Towards the last third of the video, the drive is shown inside. At the top left is the voltage doubler stage, with the capacitors. The guy uses a Fluke 867B to measure the VFD voltages - that instrument is ideally suited for the task.

Given the steep price of thes Drive Direct units, I wonder if it would not be cheaper to use a normal 400V input VFD and feed it from a 240V/400V step-up transformer up front.


Here some good information on measuring (safely!!!) on VFD's:
http://www.testequipmentdepot.com/application-notes/pdf/multimeter/multimeter-measurements-on-variable-frequency-drives-using-the-new-fluke-289-dmm_an.pdf
http://en-us.fluke.com/community/fluke-news-plus/motors-drives-pumps-compressors/how-to-measure-output-voltage-from-a-vfd-to-a-motor.html
http://assets.fluke.com/AppNotes/ElectricalPower/GO416b_u.pdf

cba_melbourne
18th Jun 2015, 10:44 PM
Honestly, you'd want to be pretty brave/competent to go scoping the output of a VFD - for starters, the output is probably floating, meaning you really want to differential probe across 2 scope channels (or use a differential probe), and even with 10:1 or 100:1 you really want a decent Cat rating on the probes - having a high divider ratio on a probe does *not* mean it's therefore designed for high voltages.

I'd expect measuring the voltage with the load attached would go some way towards dealing with the harmonic content. Also I think the DC bus is sometimes readily available for connection to a braking resistor? Again, though, I'd be really careful measuring high DC voltages with a DVM that's not properly designed for high-energy sources.

The connection for the braking resistor can be used to access the DC bus. But not all VFD's have this connections, it may not be present on economy models. If present, they are usually labelled DC+ and DC-.

I use a Tektronix THS730A handheld scopemeter, it has two fully insulated input channels. It is an old model (bought in 2001) but works fine for VFD measurements.

Stustoys
18th Jun 2015, 10:52 PM
Drives direct must have had them manufactured on order, as no one else seems to sell them.

Mine looks nothing like that one, mine is like the ones he is currently selling.
As I understand it he orders the standard Teco in a box thats big enough to take some sort of mains filter.......without the filter, so there is room for the doubler he adds...... again I have no idea where I got this info as I've never had the cover off mine.


Given the steep price of thes Drive Direct units, I wonder if it would not be cheaper to use a normal 400V input VFD and feed it from a 240V/400V step-up transformer up front.
Given the price of VSD's these days you're like correct. Though you still only end up with a single phase which I have know what DD has done about that. Though you would have a 400V supply for any controls if needed(I think) which could be handy.

Thanks for the video(omg whats going on with that motor? just some strange mic thing?) and links

Stuart

RustyArc
18th Jun 2015, 11:20 PM
I believe(though cant recall where I got the info from) that my VSD uses a voltage doubler* on the mains side then uses a standard 415V VSD.

I've always associated "voltage doublers" (a bunch of caps and diodes) with high voltage but very low current circuits, but perhaps a clever engineer has made it work. By default, I'd have assumed there'd be an inductor/transformer based DC-DC converter to boost the DC bus up to a voltage suitable for switching out at 415V levels.

GuzziJohn
18th Jun 2015, 11:22 PM
I just borrowed a mates new DSO and went to measure the voltage, turned on the VFD, hooked up the little alligator clip to one of the phases and boom, flash, #$#@....

Pointing my friend to this thread so he can see it wasn't my fault......

Lots of information has been given in this thread that could result in the above.

So, lets just leave it at no VFD will give 380/415 output from 240 in, this seems to be the consensus from those that know.

Going out to the shed to use my lathe...

Rather than attempting to measure the voltages with an external meter are these drives capable of displaying the DC bus voltage or the output voltage on the inbuilt display.

GuzziJohn
18th Jun 2015, 11:41 PM
I've always associated "voltage doublers" (a bunch of caps and diodes) with high voltage but very low current circuits, but perhaps a clever engineer has made it work. By default, I'd have assumed there'd be an inductor/transformer based DC-DC converter to boost the DC bus up to a voltage suitable for switching out at 415V levels.

There is different applications. Voltage multipliers like those used in negative ion generators produce high voltage but very little current.

Voltage doublers were often used in PC power supplies to allow 120/240 AC input for worldwide use. When used on 240 V systems a conventional rectifier was used. When selected for 120 V operation the input diodes were reconfigured as a voltage doubler.

These power supplies were rated at hundreds of watts so its easy to imagine the principle could be scaled up for multi horsepower VFD applications.

cba_melbourne
19th Jun 2015, 11:44 AM
As mentioned earlier, VFD with voltage doubler are mass produced for the North American and Japanese markets. In those cpuntries, most residential houses only have 100 or 110 or 120V power. But their 3 phase motors are 200/400V. So there exists a huge market for 100V in and 200V out VFDs.

Whereas in 220/240V contries, all newer 3 ph motors are 220/380V, so they can be hooked up directly to a 220V in VFD. There is only a minuscule niche market for customers owning an old motor or machine that only hooks up 380V, and are unwilling to upgrade their old motors. Drives Direct in the UK seem to cater for this very small niche market by adding a voltage doubler to 200V VFDs - at a considerable premium though.

DSEL74
19th Jun 2015, 12:04 PM
As mentioned earlier, VFD with voltage doubler are mass produced for the North American and Japanese markets. In those cpuntries, most residential houses only have 100 or 110 or 120V power. But their 3 phase motors are 200/400V. So there exists a huge market for 100V in and 200V out VFDs.

Whereas in 220/240V contries, all newer 3 ph motors are 220/380V, so they can be hooked up directly to a 220V in VFD. There is only a minuscule niche market for customers owning an old motor or machine that only hooks up 380V, and are unwilling to upgrade their old motors. Drives Direct in the UK seem to cater for this very small niche market by adding a voltage doubler to 200V VFDs - at a considerable premium though.


So in summary the poor forgotten OP could have what he was told he has after all?? At a cheaper price from china.

Thumbsucker have you made any progress?

cba_melbourne
19th Jun 2015, 12:31 PM
So in summary the poor forgotten OP could have what he was told he has after all?? At a cheaper price from china.


No, I do not thik so. He has a 3 phase input VFD. I am not aware of anyone making these with voltage doubler input stage (it would triple the number of input doubler capacitors and cost). Only single phase VFDs are offered by drives direct UK.

Stustoys
19th Jun 2015, 01:15 PM
at a considerable premium though.
I'm not so sure about that. If you are comparing apples with apples. The cost of a new 2.2kW Teco in au would seem to be $1080. So DD isnt to bad compared to that.(anyone know the UK price of one?)

It will be interesting to find out just what the OP has. If he has to bring out the star point its not the end of the earth. Who knows he maybe happy with half power, my camel back is.

Stuart

cba_melbourne
19th Jun 2015, 05:20 PM
I'm not so sure about that. If you are comparing apples with apples. The cost of a new 2.2kW Teco in au would seem to be $1080. So DD isnt to bad compared to that.(anyone know the UK price of one?)

It will be interesting to find out just what the OP has. If he has to bring out the star point its not the end of the earth. Who knows he maybe happy with half power, my camel back is.

Stuart

If you want to compare apples with apples, you have to compare the street prices, not the heavily inflated list prices aimed at industrial customers that anyway receive 30%+ trade discounts and do not pay GST.

Street price for a brand new 2.2kW-3HP sensorless vector TECO is AU$261 plus AU$82 postage:
http://www.ebay.com.au/itm/3HP-3PH-460V-VFD-TECO-WESTINGHOUSE-VARIABLE-FREQUENCY-DRIVE-JNEV-403-H3-/121679054739?pt=LH_DefaultDomain_0&hash=item1c54a30793

A 3HP VFD from Drives Direct is 475 pounds or 950AU$ plus postage. Not sure if it is an US made TECO though, nor does it anywhere mention it is a modern sensorless vector drive. Direct Drives put their own nameplate and labels over the makers markings. And chances are you could be slugged by our customs for GST if purchase price plus postage exceeds AU$ 1k.:
http://www.ebay.co.uk/itm/3-HP-DIGITAL-240V-415V-3-PHASE-INVERTER-CONVERTER-BRIDGEPORT-MILL-LATHE-/381284366136?pt=LH_DefaultDomain_3&hash=item58c651b738

(http://www.ebay.co.uk/itm/3-HP-DIGITAL-240V-415V-3-PHASE-INVERTER-CONVERTER-BRIDGEPORT-MILL-LATHE-/381284366136?pt=LH_DefaultDomain_3&hash=item58c651b738)

thumbsucker
21st Jun 2015, 09:11 PM
I have made progress with the VFD and my motor. Thanks allot to NCArcher who helped me via email. The process was relatively simple thanks to plain & simple instruction from NCArcher.

End the end the motor worked fine without need to make any changes. There was no need to add a 20 amp circuit to the house.

All I needed to do was purchase some 400 volt rated round lugs and forked lugs and good crimper. It took about 20 minutes and the VFD started up then I simple pressed run and the motor started up. The next step is to program the VFD. Here are some photos.

350609350608

thorens
21st Jun 2015, 10:12 PM
I have made progress with the VFD and my motor. Thanks allot to NCArcher who helped me via email. The process was relatively simple thanks to plain & simple instruction from NCArcher.

End the end the motor worked fine without need to make any changes. There was no need to add a 20 amp circuit to the house.

All I needed to do was purchase some 400 volt rated round lugs and forked lugs and good crimper. It took about 20 minutes and the VFD started up then I simple pressed run and the motor started up. The next step is to program the VFD. Here are some photos.

350609350608


this is great news . congratulation's.
so they did what they said then .
does the motor sound normal and speed up as it should ?
regards
Peter

thumbsucker
21st Jun 2015, 10:19 PM
The motor hums along nicely with a soft high pitch whizzing sound. It starts slowly revving up over 6 seconds as the hertz increases on the display. The VFD makes more noise in all honesty.

Stustoys
22nd Jun 2015, 12:09 AM
Hi Ts,
Good to see you're up and running.


so they did what they said then
Well at least in part, it is running on 240V single phase input. But the more interesting part is what the output is, it was always going to run regardless. The question is, does it have 750W or only 300ishW.



Stuart

LexD
22nd Jun 2015, 12:21 AM
Hi Ts,
Good to see you're up and running.


Well at least in part, it is running on 240V single phase input. But the more interesting part is what the output is, it was always going to run regardless. The question is, does it have 750W or only 300ishW.



Stuart

I was also wondering about the power output. This thread has been a little confusing from the start, in my opinion.

thorens
22nd Jun 2015, 01:25 AM
Hi Ts,
Good to see you're up and running.


Well at least in part, it is running on 240V single phase input. But the more interesting part is what the output is, it was always going to run regardless. The question is, does it have 750W or only 300ishW.



Stuart


Hi Stuart.
exactly . hence my question regarding how the motor run.

Peter

BobL
22nd Jun 2015, 11:39 AM
From what I can see the motor has been left in star winding connection mode otherwise there would be a pair of wires from the inside of the motor coming back to each connection point.
This means it will only generate 1/2 the power therefore restricting the usable power band.

This is a problem for machines like DPs and lathes etc the slower speeds are usually where the greatest power is needed but as TS mentioned he is a woodworker so it might work out for him.

thumbsucker
22nd Jun 2015, 11:52 AM
BobL is correct it was left in star winding and yes I am a woodworker.

I hope to have the drill press fully restored in a month.

At that point I will run the drill press through its paces, drilling assorted size holes in assorted timbers.

Then we can see in real terms if sticking with the three phase motor and pairing it with the VFD was a good idea or not.

BobL
22nd Jun 2015, 12:27 PM
The areas where I can see problems is in large holes using spade/Forstner bits and when using hole saws.
Even at full power (i.e. @ 50Hz) and set on the optimum pulley parings, with only a 3/8HP it will struggle.
But as you say, nothing beats trying it out and in the meantime a bigger and better motor may come along which will save the trouble of conversion.

FWIW I waited for over a year for my 1.5HP Leeson motor to come along. It did not need any delta to star conversions as it was dual connect at the terminal box. It's a great little motor and I am glad I waited for it.

Stustoys
22nd Jun 2015, 01:18 PM
This means it will only generate 1/2 the power

You're assuming 240V output. You may well be right. To the OP its going to sound the same either way unloaded.
I wonder if being a vector drive can make up for some of the lost power(assuming it is infact 240V output)

Stuart

BobL
22nd Jun 2015, 02:00 PM
You're assuming 240V output. You may well be right. To the OP its going to sound the same either way unloaded.
I wonder if being a vector drive can make up for some of the lost power(assuming it is infact 240V output)

Stuart

OK - forgot about these.
Vector VFD gives 10-15Hz wider range at lower end.

cba_melbourne
22nd Jun 2015, 05:58 PM
have restored a Waldown 8S too. initially I did also restore and repaint the original 1ph 1HP motor. But before putting all back together, I decided to uprade to VFD. I used a 240V V/Hz type 1HP Lenze VFD (which I already had), and bought a new 1HP 3ph CMG motor to go with it. I am very happy with performace.

I suggest the OP keeps his 3/4HP VFD, and gets a new 3/4HP 3ph 4-pole 240V motor to suit. 3ph motors are really the cheapest motors there are. There are usually some new ones on eBay for $ 80 to 90. They are chinese made - but so what, the CMG I have is made in China too, so I was told by the motor rewing shop I bought it from. Fitting to the Waldown was no problem, If I remember well I may have had to bore the pulley a bit larger because the original motor was imperial and the new one was metric:
http://www.woodworkforums.com/showthread.php?t=187240&p=1799189#post1799189

Stustoys
22nd Jun 2015, 07:58 PM
I suggest the OP keeps his 3/4HP VFD, and gets a new 3/4HP 3ph 4-pole 240V motor to suit.
Well that could be interesting to watch if you've guessed wrong.

Stuart

Chris Parks
22nd Jun 2015, 09:25 PM
I have made progress with the VFD and my motor. Thanks allot to NCArcher who helped me via email. The process was relatively simple thanks to plain & simple instruction from NCArcher.

End the end the motor worked fine without need to make any changes. There was no need to add a 20 amp circuit to the house.

All I needed to do was purchase some 400 volt rated round lugs and forked lugs and good crimper. It took about 20 minutes and the VFD started up then I simple pressed run and the motor started up. The next step is to program the VFD. Here are some photos.


Tony is the got to guy for this stuff and has never failed to solve any VFD related issues put to him in my experience. He actually is a qualified expert in this field.