Arc-faults for AC circuit

[Jerry Simon]

Two separate 120-volt, arc-fault types of circuit breakers were protecting the 240-volt air conditioner's circuit at a house.  I know a 240-volt breaker should be installed, but what about the use of arc-fault breakers?  I suspect nuisance tripping might occur.

Edited September 23, 2018 by Jerry Simon
f

[Marc]

The compressor motor has no brushes and those little window units don't have start capacitors that switch out, so I don't see why it would trip an AFCI, assuming no defect.

Do the codes call for an AFCI on a window unit?

[Jim Katen]

6 hours ago, Marc said:

Do the codes call for an AFCI on a window unit?

 

Not if its fed with 240 volts. The NEC only requires AFCI protection on 120-volt single phase 15- and 20-amp circuits.