MOCP 15 amp

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rose1981

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I have a mech equipment with MOCP 15Amp. If I use a 20 Amp breaker, is that a code violation?

or should I install a 15Amp fused disconnect switch at the equipment fed from a 20amp breaker in the panel board?
 
MOCP = MAXIMUM Over Current Protection.
20A>15A, ergo it would be a violation.

Yes, you can certainly use a 15A OCPD fed from a 20A feeder, in fact you must, unless you simply change out the breaker in the panel board to 15A.
 
rose1981 said:
I have a mech equipment with MOCP 15Amp. If I use a 20 Amp breaker, is that a code violation?

or should I install a 15Amp fused disconnect switch at the equipment fed from a 20amp breaker in the panel board?
Click to expand...

It may or may not start, if not, the NEC doesn't care, as long as it's safe. You can put a 20A breaker on the HV side of a transformer rated for 1000A. You won't get more than 20A out of it, but NEC doesn't care as long as the 20A circuit install meets NEC.
 
kingpb said:
It may or may not start, if not, the NEC doesn't care, as long as it's safe. You can put a 20A breaker on the HV side of a transformer rated for 1000A. You won't get more than 20A out of it, but NEC doesn't care as long as the 20A circuit install meets NEC.
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There shouldn't be a starting issue. The OP says the MOCP (maximum overcurrent protection) is 15 amps.
 
It may be code violation, if manufacturer calculated MOCP according table 430.52 and gives you that number. If put fuse bigger that per table 430.52 it is violation.

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What will happen if mechanical internal wiring rated for 15A (16awg) and you put 20 or 25 branch circuit? NEC doesn't care about this situation? How much bigger you can but branch circuit?

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victor.cherkashi said:
What will happen if mechanical internal wiring rated for 15A (16awg) and you put 20 or 25 branch circuit? NEC doesn't care about this situation? How much bigger you can but branch circuit?

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You can't use 16 awg for 15 amp branch circuits, it would need to be 14 awg. I am not sure what you are asking, but if the internal wiring is part of a UL approved assembly, it would be fine. In the case of motor loads, you could have a 40 amp breaker feeding 14 awg wire. The wire is actually protected by the motor overloads.
 
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