# one circuit or two?



## goose134 (Nov 12, 2007)

I don't do a lot of motor work, so forgive me if this is a 101 question. I have a setup that has two pump motors that will be used alternately through the use of a sequencer. The loads are small (3 [email protected] 480 v)) and will be protected by individual overload protection. Can I power the two motors with one circuit or do I need a circuit for each?


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## HARRY304E (Sep 15, 2010)

goose134 said:


> I don't do a lot of motor work, so forgive me if this is a 101 question. I have a setup that has two pump motors that will be used alternately through the use of a sequencer. The loads are small (3 [email protected] 480 v)) and will be protected by individual overload protection. Can I power the two motors with one circuit or do I need a circuit for each?


You only need one circuit because they are only 3 amps and they will not be running at the same time.

And even if they were that's only a 6 Amp load.:thumbsup:


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## Jlarson (Jun 28, 2009)

I don't see anything there that would make it so you couldn't put both on the same branch circuit. 



Although If its a critical app putting them on one circuit could come back to bite of one motor shorts and trips the breaker.


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## alpha3236 (May 30, 2010)

Perfectly legal, size the wire at 125% of the largest motor plus the other motor. Do it all the time.


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## goose134 (Nov 12, 2007)

Good point about the critical load. I think in a different case I'd put them on seperate circuits just for a bit more certainty. This is pumps for a air conditioning setup. I didn't think it would be a problem, but I wanted to find out from guys who knew much more than me. Thanks again.


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## BBQ (Nov 16, 2010)

220.60 Noncoincident Loads. Where it is unlikely that
two or more noncoincident loads will be in use simultaneously,
it shall be permissible to use only the largest
load(s) that will be used at one time for calculating the total
load of a feeder or service.


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## oliquir (Jan 13, 2011)

alpha3236 said:


> Perfectly legal, size the wire at 125% of the largest motor plus the other motor. Do it all the time.


that rule is ok but don't use smaller than 14 awg :whistling2:

you can even use only one overload protection for the 2 motors if the contactors for the 2 motors are interlocked (similar to a reversible contactor) since only one will run


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## goose134 (Nov 12, 2007)

Bob brings up an interesting point. I'm not 100% sure of the circuit logic, but I think it's designed to run the pumps as alternates. I do know that the sequencer allows for an operation that would ramp one down while running the other up. Now I'm pulling#10 THHN but if the logic is set in the way I just described, would it be a violation?


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