3 Ph 200v Compressor

[JMWElectric]

I have read a lot about 200v compressors and before I move forward with purchasing a transformer to make this work I wanted to double check if anyone knows if I can make this work on my current shops set up.

Service:

120/240 3 phase with a delta high leg
any advice would be great.

 

[jumper]

I cannot read that paper, too small.

Figure out what kVA you need and get 240-208/120V D-Y tranny.

 

[ActionDave]

I have read a lot about 200v compressors and before I move forward with purchasing a transformer to make this work I wanted to double check if anyone knows if I can make this work on my current shops set up.

Service:

120/240 3 phase with a delta high leg
any advice would be great.

Spend your money on a 240V motor. Don't spend money on a transformer. It's way easier to change the motor than it is to buy and wire up a buck boost.

 

[ptonsparky]

You may need to spend another $100 on the control transformer and a few bucks on overloads, but I agree, get the new motor.

 

[kwired]

I bet there is a good chance the motor has OEM specs and you won't be putting in any general purpose motor as a direct replacement - it will need modifications. If under 15 HP may still be worthwhile.

I might suggest change to control transformer if it don't have 240 volt taps for sure, but otherwise tell owner it may not last as long on 240 volts, but will probably last a pretty long time anyway, unless it runs 24/7 at full load rating or something like that.

If it a warranty issue - someone needs to decide whether to comply or allow the warranty to be voided.

If it is new - why didn't they order the correct version for what you have for supply voltage in the first place?

 

[Besoeker]

Spend your money on a 240V motor. Don't spend money on a transformer. It's way easier to change the motor than it is to buy and wire up a buck boost.

Well said that man.
Apart from anything else, the transformer will add to the system losses. But around 2% for a good transformer - forever.

 

[Besoeker]

If it is new - why didn't they order the correct version for what you have for supply voltage in the first place?

You have to wonder...........

 

[jumper]

You have to wonder...........

The OP is the customer and he has not ordered anything. It is a personal project he is thinking about for his shop. OP is an EC.

 

[kwired]

The OP is the customer and he has not ordered anything. It is a personal project he is thinking about for his shop. OP is an EC.

I can't read much either on his drawing - gets too blurry when you enlarge it. But looks like the thing possibly can be configured for different voltages. Sure looks like motor is capable of being configured for 480 volts, if so I see it being suitable for 240 volts before it will be rated for 208 volts. After that control transformer may be all that is left that needs attention.

 

[Besoeker]

The OP is the customer and he has not ordered anything. It is a personal project he is thinking about for his shop. OP is an EC.

OK. Why even think about something that is not matched to his supply voltage?
I'm simply asking the why. It isn't an issue we routinely come across here. And even if it was a non-standard voltage, we knew that going in and designed accordingly.
It seems to me that this analogous to the OP's situation. He knows the voltage his shop has. So why even consider a piece of kit that is a mismatch and may require extra kit to make it match?

To the OP:

Is the problem that you can't get a 240V 3ph compressor? Or are they too expensive?

 

[kwired]

OK. Why even think about something that is not matched to his supply voltage?
I'm simply asking the why. It isn't an issue we routinely come across here. And even if it was a non-standard voltage, we knew that going in and designed accordingly.
It seems to me that this analogous to the OP's situation. He knows the voltage his shop has. So why even consider a piece of kit that is a mismatch and may require extra kit to make it match?

To the OP:

Is the problem that you can't get a 240V 3ph compressor? Or are they too expensive?

He probably got a steal on whatever it is he ended up with - now has to make it work. It was likely connected to a 208 volt system before, is possible it can be configured for 240 volt system. Motor itself will likely be fine on 240 volts even if only labeled for a 208 system, that leaves you with lesser expensive item of a control transformer that may need changed if it can't be configured for 240 volts input. I would run the motor on 240 until it burns up - probably will be a long time before that happens anyway.

 

[norcal]

He probably got a steal on whatever it is he ended up with - now has to make it work. It was likely connected to a 208 volt system before, is possible it can be configured for 240 volt system. Motor itself will likely be fine on 240 volts even if only labeled for a 208 system, that leaves you with lesser expensive item of a control transformer that may need changed if it can't be configured for 240 volts input. I would run the motor on 240 until it burns up - probably will be a long time before that happens anyway.

My guess it was a auction find, a local scrapyard with multiple locations bought a I-R compressor with a 200V single voltage motor at auction, (to my knowledge I-R will not supply a tri-volt 200-230/460V motor to use on 208V, only a 200V motor), but the voltage at that yard is 120/240V 3Ø, someone just wired it & plumbed it as-is.

 

[kwired]

My guess it was a auction find, a local scrapyard with multiple locations bought a I-R compressor with a 200V single voltage motor at auction, (to my knowledge I-R will not supply a tri-volt 200-230/460V motor to use on 208V, only a 200V motor), but the voltage at that yard is 120/240V 3Ø, someone just wired it & plumbed it as-is.

I ran into similar but was three phase unit and shop it was at only has single phase power. Someone installed a static phase converter, which probably cost enough to consider replacing motor with single phase - though a standard general purpose motor wasn't the same fit as the OEM. Problem they were concerned with when I got involved is frequent tripping of motor overload.

I found static phase converters are mostly suitable for stead load - when the unit was getting near cut off pressure it was loaded quite a bit more then when at or below mid range pressures, and that you basically need to change capacitors to get correct phase balancing as the load changes - no all that practical of a thing to do with this application.

We set the overload so it won't trip at high pressures - and told them if and when the motor burns out it should be replaced with a single phase motor - they weren't willing to spend $$$ on a VFD or rotary converter after spending $$$ already on the static converter.

I suspect the condition it was in - they never installed covers on it that the compressor wasn't going to last as long as the motor anyway - covers looked like they were needed to direct airflow to cool the compressor:happysad:

 

[Ingenieur]

the dwg shows a 440-460 or 220-230 motor?

a 15% buck xfmr should do it

240-208 https://www.schneider-electric.us/en/faqs/FA91925/
what is fla at 200 vac?

 

[Besoeker]

the dwg shows a 440-460 or 220-230 motor?

a 15% buck xfmr should do it

240-208 https://www.schneider-electric.us/en/faqs/FA91925/
what is fla at 200 vac?

The question to the OP remains why go down that route?
As I said to Dave the Rave, it's more losses. Also, it's at least another half a dozen points of potential system failure.
Makes no sense unless there is information that has not been shared.

 

[Ingenieur]

The question to the OP remains why go down that route?
As I said to Dave the Rave, it's more losses. Also, it's at least another half a dozen points of potential system failure.
Makes no sense unless there is information that has not been shared.

he can likely get it very cheap, a fraction of a new unit, and probably industrial quality since it appears to be a 208/3 unit
and the only extra component will be the buck xfmr (2 x 2.5 kva) which are not $$$
and xfmrs are very reliable

 

[jumper]

As I said to Dave the Rave,,,,,,.

Are you implying that ActionMan is a raving lunatic?

If so, I agree.

I think the thin mountain air might be partially responsible.

 

[Besoeker]

Are you implying that ActionMan is a raving lunatic?

If so, I agree.

I think the thin mountain air might be partially responsible.

Um....no safe answer to that................
I had a relative, Dave, who played in a rock band. All the family knew him as Dave the Rave. Great guy. Actionman should take that as a compliment.........

 

[Jraef]

Before doing anything, go read the actual motor nameplate. This is a somewhat generic drawing package that is adaptable for many options. None of the motor options shown are for 200V, but there is a reference to modifying the thermal trips of the motor protector switch (F1) to a value for 200V. This to me would imply that they are using a motor fully capable of 200-240V, all you need do is tweak the OL protection depending on what you have supplying the machine. This is not an uncommon strategy for OEMs, it reduces the motors they must stock.

So if the motor nameplate does indicate it is good for 200-240V, all you need to do to make it work on 240V is tweak that OL relay setting down a little from the 200V setting.

 

[Besoeker]

Before doing anything, go read the actual motor nameplate.

Sound advice as ever.
And I agree, it looks like a generic drawing with several motors shown.
But I'm not sure that he actually has the piece of plant yet.
Perhaps the OP could clarify that.