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#61984 - 02/07/06 03:19 PM Need a little help
scjohn Offline

Registered: 07/04/02
Posts: 76
Loc: charleston, SC, USA
I have a foreign piece of equipment that is 3 phase 380 volt 23kw with a 60 amp start up and 45 amps running. This equipment came with a step-up or buck & boost transformer that is 30kva with a 3 phase 208 deta for primary and 400/231 y secondary. The problem I have is the building only has single phase 240volt power so I guess I need a phase converter. Is a 30kva converter enough, and what can I expect my load to be on the single phase circuit supplying all this? This piece of equipment is extremely vital and expensive, I don't want to screw it up.

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#61985 - 02/07/06 04:52 PM Re: Need a little help
Larry Fine Offline

Registered: 02/18/05
Posts: 684
Loc: Richmond, VA
If the converter is rated to supply 30kva, and the load requires 23kw, you're probably okay, but the difference between kW and kva, the ratio being the power factor, could overload the conveter.

The best bet is to contact the converter maker with the specific specifications (is that redundant?) of your equipment for proper application.
Larry Fine
Fine Electric Co.

#61986 - 02/08/06 04:27 AM Re: Need a little help
Dnkldorf Offline

Registered: 12/12/04
Posts: 1091
Loc: nowhere usa
scjohn, I did a search here on this site, and there was talk of derating phase convertors, up to 57%....

I have very limited experience with these, but will tell you, rotary convertors put out a high leg, and this should not be used for control circuits. If your equipment is "vital and expensive" as you say, then Larry's advise would be prudent. Contact both, the convertor manufacturer and the equipment manufacturer prior to installation.....


#61987 - 02/08/06 07:15 PM Re: Need a little help
scjohn Offline

Registered: 07/04/02
Posts: 76
Loc: charleston, SC, USA
Actually the step-up transformer that came with it states a 208 delta for a primary. This in itself is confusng me a little. I always thought that a delta was 240volt with a high leg, and 208y was 120volt from each line to ground. The secondary of the transformer is 400/235 y.


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