Can HOM and QO CAFI breakers be used on 208Y/120 systems?
Arc-fault (CAFI and DF) breakers
All single-pole QO and HOM breakers with CAFI and DF suffixes can be used on 208Y/120 systems. These systems are 120 V to ground/neutral and these breakers are designed for this voltage.
Two-pole CAFI and DF type breakers however will not work on 208Y/120 systems. They are designed for 120/240 systems only and will trip on 208Y/120 systems when energized.