Contactor Size

[masterelect1]

What size contactor do I need for a 250 amp supply to a rotary phase converter?

Thanks,
John

 

[bphgravity]

I assume you a refering to NEMA size?

What is the continuos current rating and horsepower rating of the equipment?

 

[masterelect1]

Yes NEMA size - the contactor is to start/stop a 1ph 208 volt rotary phase converter which is listed @ 30kw and 250 amps- I'm guessing size 4 but I don't have the literature available at this time.

 

[Jraef]

Size 5 if you go by NEMA sizes. otherwise, anything rated 250A.
NEMA Size 4 is good for 135A
NEMA Size 5 is good for 270A

 

[mdshunk]

I guess it was pointed out to me the other week that rotary phase converters don't require starters or overloads units of any sort. Just an ordinary OCPD.

 

[masterelect1]

I guess it was pointed out to me the other week that rotary phase converters don't require starters or overloads units of any sort. Just an ordinary OCPD.

For clarification, I know that. The contactor controlled by a selector switch or other control means affords the opportunity to control the RPC from a remote location without civilians going into the Dist Panel and flipping brkrs.