ActronAir 3-Phase Relay Protection OMRON K8DS-PH1 monitors 3-phase supply quality for commercial ActronAir systems, providing protection against phase loss, phase imbalance, and incorrect phase sequence that would otherwise cause compressor and 3-phase motor damage. The K8DS-PH1 must be set to the correct voltage, imbalance, and trip delay settings during commissioning -- incorrect settings provide inadequate protection or cause nuisance trips. Isolate power at mains before replacing any 3-phase protection relays.