Phase monitoring relay for three-phase motor protection
The ABB 1SVR730774R3300 CM-PAS.41S is a phase monitoring relay that detects phase failure, phase sequence reversal, and phase unbalance on three-phase supplies. It's self-powered from the monitored lines — no separate control supply needed — drawing its operating voltage from the L-L measurement input. The measuring range covers 300...500 V AC line-to-line at 50/60 Hz, which covers standard 400 V and 480 V industrial mains without external PTs. The relay trips when any phase drops out, the rotation reverses, or the unbalance exceeds the internal threshold.
DIN-rail fit and environmental range
The supply frequency is rated for both 50 Hz and 60 Hz networks, making the same part usable on European and North American three-phase systems without a variant change.
Current lifecycle and sourcing posture
Sourced to order against the BOM quantity through independent distribution. Availability and current pricing confirmed at RFQ time.