# 6 copper on a 90 am breaker.

[reyamkram]

I came into a came situation, where there is a #6 wire on a 90 amp breaker, the line side feeds a disconnect fused at 50 amps, on the load side it feeds an air compressor,
per the manufacture specs and name plate + 125%, it is fused correctly. the Question is, I can not find any thing In the NEC, that would say it is OK, to put a #6 THHN copper wire on a 90 amp breaker 75 deg, and I ask the person that did, and was told It is OK, nothing will happen.
Well, what I understand, on the load side side a ground fault and/or short will open the OCPD, but, the line side, the wire would melt and/or burn, and pose a probable elect

Thank you, for any information, and concerns.

 

[kwired]

Sounds like many the 10 HP 240 volt single phase motors I have connected.

General rules don't allow 6 AWG on 90 amp breaker. Rules in art 430 will, and in fact could be up to 125 amp breaker per rules there.

Air compressor would be covered here as it is motor driven. You might get away with lesser breaker but the risk is it won't hold during starting. 60 amp time delay fuse would be pretty common for 10 HP motor. If 50 amp fuse is there and never blows, that compressor is either not 10 HP or is never loaded to that kind of level for very long.

This 90 amp breaker is only for short circuit and ground fault protection. The motor overload will also protect the conductors from overload.

 

[retirede]

How long is the run of #6s? Anything else on the 90?

Tap rules could play.

 

[zbang]

Or electric welder rules if the circuit was reused for the AC.

 

[infinity]

Nothing will happen to the #6's protected by the 90 amp OCPD. Is it code compliant, maybe, maybe not.

 

[reyamkram]

How long is the run of #6s? Anything else on the 90?

Tap rules could play.

The run is about 30 feet from breaker panel to disconnect, and no there is nothing else connected on that line.

Thank you.

 

[electrofelon]

Could probably even go higher than 90. See 430.52.