[DennisCNC]

Is there a transformer available to step up from 220 to ~400V 3 phase? I got a plasma cutter and it uses 400V.

[Al_The_Man]

First check if it runs 400 or is it 460? If made for the N.american market it is usuall 460.
Many Plasma cutters have voltage option taps, some even have automatic voltage selection (Hypertherm).
You can run a 460 to 220 transformer 'backwards' but most manufacturers have a de-rating factor if used this way.
Hammond Transformers could have what you are looking for.
Al.

[DennisCNC]

It says 400-460 its either 400 to 460 / 400 or 460.

Al, thanks I will look in to Hammond

[torinwalker]

I found a 7.5kva 600 --> 120/240V transformer for $80! A transformer of this size/type is just too sweet to pass up, and if I can run it in reverse, it'll be eactly what I need to run the 575V 1ph VFD that will run my 575V 3-ph mill (from my poorly endowed 240V 1ph garage)

Data on this tranformer is scarce; The manufacturer, Polygon, appears not to have a website, so I thought I might pose this question here in case anyone easily recognizes the specifications.

I've attached a picture of the unit and its specification placard. The placard shows a 600V primary and 120/240 secondary, and it shows... three taps on the primary?

Could someone confirm or deny my suspicions?

I think:

1. At 3HP max (the power of my new Ex-cell-o), I am well within the ratings of this transformer, even in reverse.
2. The secondary has two windings of 120V each that can be wired in parallel or series. (I would connect in series to use on my 240V 1ph service.)
3. The primary has three positions (taps?) of 627, 600, and 573. I would use the third tap as the output to get 575V out.

Ahh... if only I knew everything beforehand, my life would be much simpler.

Thanks (for the umpteenth time) everyone.


Torin...

[Al_The_Man]

I ran one for a tap dis-integrator that was about that size.
You should be OK with a 50amp breaker on 240.
Al.

[torinwalker]

Al,

Tap disintegrator... funny.

And what about the positions of 627, 600, and 573 shown on the placard? Do you think they are taps on the primary?


Torin...

[ashad]

Please check the website

elabsp - elab Solution Provider
For
Power Electronics Tutorials

[torinwalker]

ashad,

Thanks. I went through the transformer basics and, while I kinda knew all that stuff already, it did mention that mutliple taps to accomodate different voltages is a common design feature which reinforces my notion that those "positions" labeled on the placard are probably what I suspected they were: taps.

I just wanted to hear it from someone who actually knows, or at least, who knows more than I do. Electricians, particularly, probably have this stuff down pat.

I'll probably head out there on Sunday to pick up this little diamond in the rough and save myself nearly $200 on the purchase of a 5kva transformer I had originally intended to buy.

Thanks again.

Torin...

[mike_Kilroy]

You are correct; those are the 3 inputs possible; 600v nominal and +/- 5% taps around it. 600v was common for a while (not sure if it still is) in some parts of canada I think at automotive plants. we sold a lot of 600v transformers years ago to canada.

[torinwalker]

Thank you, Mike.

I ran a manufacturing shop well over a decade ago and everything in that shop was 575 3-ph at least as far as the equipment was labelled. I had an electrician who would come in and drop new lines and so forth, so I never looked in the electrical room to see if it was 600V or 575V. I once wired a new 3-ph motor in delta instead of wye configuration - it only took a minute or two before it smoked and I had to have it rewound to the tune of $350. Needless to say, I'm a little more careful these days.


Torin...

[Al_The_Man]

Most machines are fairly tolerant of voltage level, ±10% is usually the accepted tolerance.
Is the VFD that you have, designed or accept the ability to run on 1 phase?
Al.

[mike_Kilroy]

I found a 7.5kva 600 --> 120/240V transformer for $80! A transformer of this size/type is just too sweet to pass up, and if I can run it in reverse, it'll be eactly what I need to run the 575V 1ph VFD that will run my 575V 3-ph mill (from my poorly endowed 240V 1ph garage)
Torin...

Torin, you have a 1ph 575v input VFD that runs a 3ph 575V motor.... Who makes those nowadays for you guys up north? I haven.t paid attention to 575v drives for a long time!

BTW, IIRC the Ford motor company is the one who changed the 575v to 600v standard in some Canada locations and we had to change our transformers to this as the nominal with taps up/down around it for them. But they bought a hole lot of em so we didn't complain!

[torinwalker]

Al and Mike,

The VFD is an Allen-Bradley PowerFlex 70. According to the User Manual for the drive, it can be run from 1-phase so long as it is derated by 50%. The guy who originally wanted to sell me the VFD kept telling me that 5HP was enough, but I wasn't satisfied - call it intuition, call it paranoia, but I decided to bump it up to 7.5HP to keep it safe and ended up purchasing a 7.5HP PowerFlex 70 off ebay for $100 less than the price originally asked for the 5HP version.

Mike, I am not in the know about who normally sells 600V/575V stuff here in Canada. I'm just a hobbyist/jack-of-all-trades who tinkers in his 240V 1ph garage. I can tell you that there is a lot of 575V equipment in Canada based on all the advertisements for equipment sold here, but little about the 575/600 shift in the trend for equipment power.


Torin...

[vanjast]

Is there a transformer available to step up from 220 to ~400V 3 phase? I got a plasma cutter and it uses 400V.

You're probably looking for an 1-phase to 3-phase converter (The Inverters AC equivalent).
There might be a transformer based one, but these would be really heavy (the magnetics) but the most robust.

An electronic one would be lighter and more efficient, but more prone to breakdowns, depending on usage.

[Al_The_Man]

You're probably looking for an 1-phase to 3-phase converter (The Inverters AC equivalent).
There might be a transformer based one, but these would be really heavy (the magnetics) but the most robust.

An electronic one would be lighter and more efficient, but more prone to breakdowns, depending on usage.

I think he may have found an answer since 2005
Al.

[vanjast]

:banana:
:cheers: