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Can a QO or HOM 2-pole Arc-Fault CAFI breaker be used to feed a SINGLE LOAD that uses both 120V and 240V in that one load?

Product Line:
Circuit Breakers

Environment:
QO and HOM 2 pole Arc Fault Circuit Breakers with these catalog numbers:
  • QO215CAFI
  • QO220CAFI
  • HOM215CAFI
  • HOM220CAFI

Resolution:
QO and Homeline 2-pole Arc-Fault breakers are rated 120/240V, meaning they are rated for use on a 1Ø-3W system that has 120Vac L-N, and 240Vac L1-L2. Currently, the code requires AFCI protection on many 15A and 20A, 120V circuits (but NOT 240V). Because of the code requirement, all of our testing to date has been on 120V loads. Even for an installation in which a 2p CAFI breaker feeds (2)120V circuits that have a common neutral (shared neutral), all the loads fed by that breaker are still 120V.

What about the situation in which a SINGLE LOAD requires BOTH 120V and 240V? Electrically-speaking, since all the load conductors (L1, L2, N) would pass through the 2p breaker to that one load, at first it seems to make sense it would be ok. However as pointed out, the code does not require AFCI for 240V circuits. Therefore QO and HOM CAFI 2p breakers have not been tested on those any 240V loads. Testing is important. Some types of 240V loads may inherently have some leakage to ground, which could cause the 2p CAFI breaker to trip. 

Therefore since the code does not require AFCI protection for 240V circuits, and we have not tested the suitability of use with 240V loads, we don't recommend using 2-pole QO or HOM Arc Fault breakers to feed a single 120/240V load.
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