Thread: recommend VFD for 1hp motor

Originally Posted by RayG

no idea on price

I dont recall seeing one for less than $1500+, most I've seen don't have a price online.

Here's one.

http://www.ebay.com.au/itm/Single-to...ht_1361wt_1000

The fail-proof thyristor devices are "extreemly reliable"....I'm going to have to look up the meaning of "fail-proof" hehe

Stuart

Originally Posted by Stustoys

I dont recall seeing one for less than $1500+, most I've seen don't have a price online.

Here's one.

http://www.ebay.com.au/itm/Single-to...ht_1361wt_1000

The fail-proof thyristor devices are "extreemly reliable"....I'm going to have to look up the meaning of "fail-proof" hehe

Stuart

Thanks Ray and Stuat.
a bit too rich for my blood
a quick search showing one used from QLD but it still over a grand ,
any other way ? may be best to change the motor ? cheaper .
Peter

You could always build your own RPC .. a few people on here have done it, and I'm sure there are notes on the internet on how to go about it.

Ray

$525 make you feel any happier?(save about $50 if you buy direct from their site..... to pay for postage. save 20% more if you can talk him out of charging VAT)

http://www.ebay.co.uk/itm/1-HP-DIGIT...item231f361fe8

For $11 this is a good read (even if it only talks you out of making one............and even better read if it talks you into making one)

http://www.bookdepository.com/search...arch=Find+book

Stuart

Can you feed a VFD 415V single phase?

Say you have a 240-415V transformer...

Can a VFD run more then one motor at the same time?

Originally Posted by .RC.

Can you feed a VFD 415V single phase?

Say you have a 240-415V transformer...

Can a VFD run more then one motor at the same time?

I was thinking about step up transformer as well but they not cheap either .

Peter

Originally Posted by .RC.

Can you feed a VFD 415V single phase?

As I understand it thats exactly what the drives direct 240-415V VSD does. Using a voltage doubler infront of a 415V VSD. Either de-rating the VSD or modify the rectifier.

Originally Posted by .RC.

Can a VFD run more then one motor at the same time?

You mean in the same way as a rotary phase converter?
Then "mostly" no, though there are VSDs that can.

The "mostly" part. Drives direct say you can turn the coolant pump on and off as you please. I'm yet to try that out.

Stuart

Originally Posted by .RC.

Can you feed a VFD 415V single phase?
Say you have a 240-415V transformer...

Yes, you could feed a 240 to 415 step up transformer and feed single phase to the vfd, some 415 3 phase input vfd's will alarm on missing phases, but some are ok.
I know that Danfoss has a drive that takes 480 single phase input. For a vfd that normally expects 3 phases in, and you only have one, you have to de-rate the vfd accordingly.

Can a VFD run more then one motor at the same time?

Depends on the vfd, a simple V/F vfd can run multiple motors at once, not desirable but it works fine. I run the Hydraulics pump and the coolant pump off one vfd.

Ray

Some CIG stick welders the transformer in them can take inputs of 240-415-480V... It is possible to feed 240 in and get 415 out... Usually these welders sell cheap...

I do not know how the cheap common VFD would go, whether you can run the two motors off the one drive plus also have the one motor still be dual speed capable...

I know in the setup you have to specify the number of poles, but that could just be so the speed indicator on the VFD shows the correct motor speed..

Hello,

Ok so you have a 415 volt three phase motor. It is not able to be have the windings reconfigured to run on 240 volt 3 phase. You only have a single phase supply to run it from...

1) Three phase 240 volt motors are available, see your local industrial sparky. If you want to keep your machine (Hardinge) somewhat original you can source the appropriately rated motor from the USA as some parts of the USA run 220 volt three phase. The freight cost will likely be $400 to $500 and a Hardinge motor $200 to $300. You can find generic 1.5 h.p. 220 Volt motors on Ebay.com for around $200. You will require a VFD to get 3 phases at 240 Volts phase to phase. Total cost around $1k. You should use a licensed electrician for the motor install.

2) Rotary phase converters are not cheap, tend to not have well balanced outputs which are also not 120 degrees apart. They will work. You should use a licensed sparky for the installation of the phase converter for legal and warranty reasons. You could build your own if you know enough about electrical stuff. In the example of a high quality lathe, I wonder if the lack of electrical balance etc would adversely affect the surface finish due to extra vibrations in the drive system???

3a) It maybe possible to use a VFD to give you 3 phases at 240 volts phase to phase then a transformer to step this up. There are, or were, two 415 volt to 200 volt three phase transformers on ebay.com.au from an Adelaide vendor a few weeks ago. Set your VFD to give 200 volts max output and feed this into the secondary side of the transformers. This may or may not work as it depends how well the transformers handle the output of the VFD. If the VFD has a good sine wave output, all should be well. No guarantees as I have not tried this, tempted as I was. The freight cost of the transformers killed it for me. You would want to check that the transformers are suitable as it was hard to tell from the vendors description. Expect to spend $1k or so.

3b) Obtain 3 x 240/240 volt isolating transformers wire one side in delta and the second side in star. That will give you 415 volts. Untried theory as per 3a above.

4) As per RC's suggestion obtain an old CIG welder and run it from 240 volts. Tap off the 415 volts to run a 415 volt VFD. Note this will be only one phase and you will need to find a VFD (de)rated for this as per RayG above. You can also use this as a stick welder should you wish. Somone, somewhere has probably tried this. Until you hear from them, I'd suggest this is theoretical as well

(it occurs to me at this point that it's just as well we all have really big sheds and lots of room for all these boxes!!!)

5) Obtain 2 x 240/240 volt isolating transformers. Wire them with one having reversed polarity compared to the other so that the outputs can be summed to be 480 Volts and feed this into your 480 volt VFD as per 3b above. Another untried theory!

6) Pay very large sums of money and have three phase connected to your property. Cost involved will be proportional to your distance from the last 3 phase supply of your distributors network.

7) Use a voltage doubling circuit on the input side of your VFD. You maybe able to buy such a device off the shelf, I'm thinking it will be expensive as China & Co. aren't selling these by the millions. If you know some electronics you could build your own. A course of action for the knowledgeable and brave!


In summary option 1 is probably the most elegent. It's also the least fun! Option 6 will be the most expensive but will be very satisfactory. It will be helpful to have a tame sparky in all situations.

Choose your poison carefully.


Cheers

The Beryl Bloke

Originally Posted by Theberylbloke

Hello,

Ok so you have a 415 volt three phase motor. It is not able to be have the windings reconfigured to run on 240 volt 3 phase. You only have a single phase supply to run it from...

1) Three phase 240 volt motors are available, see your local industrial sparky. If you want to keep your machine (Hardinge) somewhat original you can source the appropriately rated motor from the USA as some parts of the USA run 220 volt three phase. The freight cost will likely be $400 to $500 and a Hardinge motor $200 to $300. You can find generic 1.5 h.p. 220 Volt motors on Ebay.com for around $200. You will require a VFD to get 3 phases at 240 Volts phase to phase. Total cost around $1k. You should use a licensed electrician for the motor install.

2) Rotary phase converters are not cheap, tend to not have well balanced outputs which are also not 120 degrees apart. They will work. You should use a licensed sparky for the installation of the phase converter for legal and warranty reasons. You could build your own if you know enough about electrical stuff. In the example of a high quality lathe, I wonder if the lack of electrical balance etc would adversely affect the surface finish due to extra vibrations in the drive system???

3a) It maybe possible to use a VFD to give you 3 phases at 240 volts phase to phase then a transformer to step this up. There are, or were, two 415 volt to 200 volt three phase transformers on ebay.com.au from an Adelaide vendor a few weeks ago. Set your VFD to give 200 volts max output and feed this into the secondary side of the transformers. This may or may not work as it depends how well the transformers handle the output of the VFD. If the VFD has a good sine wave output, all should be well. No guarantees as I have not tried this, tempted as I was. The freight cost of the transformers killed it for me. You would want to check that the transformers are suitable as it was hard to tell from the vendors description. Expect to spend $1k or so.

3b) Obtain 3 x 240/240 volt isolating transformers wire one side in delta and the second side in star. That will give you 415 volts. Untried theory as per 3a above.

4) As per RC's suggestion obtain an old CIG welder and run it from 240 volts. Tap off the 415 volts to run a 415 volt VFD. Note this will be only one phase and you will need to find a VFD (de)rated for this as per RayG above. You can also use this as a stick welder should you wish. Somone, somewhere has probably tried this. Until you hear from them, I'd suggest this is theoretical as well

(it occurs to me at this point that it's just as well we all have really big sheds and lots of room for all these boxes!!!)

5) Obtain 2 x 240/240 volt isolating transformers. Wire them with one having reversed polarity compared to the other so that the outputs can be summed to be 480 Volts and feed this into your 480 volt VFD as per 3b above. Another untried theory!

6) Pay very large sums of money and have three phase connected to your property. Cost involved will be proportional to your distance from the last 3 phase supply of your distributors network.

7) Use a voltage doubling circuit on the input side of your VFD. You maybe able to buy such a device off the shelf, I'm thinking it will be expensive as China & Co. aren't selling these by the millions. If you know some electronics you could build your own. A course of action for the knowledgeable and brave!


In summary option 1 is probably the most elegent. It's also the least fun! Option 6 will be the most expensive but will be very satisfactory. It will be helpful to have a tame sparky in all situations.

Choose your poison carefully.


Cheers

The Beryl Bloke

after read all the above mentioned option. i think this should be a good answer .
http://www.ebay.co.uk/itm/2-HP-DIGIT...item58ace66523

what you reckon ?

Peter

Looks like a goer to me.

It also says it can handle the dual speed mottos.
I wonder if you have to turn off the VFD to switch to the other motors speed.
Maybe you just have to make sure the VDF is not delivering power when switching - if so you may need a bit of control circuitry to prevent that happening.
If it doesn't say that anywhere in the destructions I would make sure you clarify this before installing/

There are a couple of those on the forum. Stuart has one, so he could comment further. Ken has another, I recall he had trouble getting them to not charge VAT or something..

They remove the filtering to make room for the voltage doubler, so I suspect they aren't c-tick approved.

Underneath, they are a TECO drive, that Drives Direct buy from TECO and modify them.

Ray

Originally Posted by BobL

I wonder if you have to turn off the VFD to switch to the other motors speed.

You mean the 240V input? Then NO

Originally Posted by BobL

Maybe you just have to make sure the VDF is not delivering power when switching .

Yes. But you also dont really want to turn the VSD back on until the motor has stopped as the TECO doesnt have a "catch up" start option(if I recall correctly and if if hasnt been added)

Originally Posted by BobL

if so you may need a bit of control circuitry to prevent that happening.

It could be done simply enough(well at least with coasting stop and forgetting the point above about not turning the VSD back on before the motor stops turning), but how many of us that circuitry to prevent us changing gearbox speed while the motor is on?

Stuart