This relay operates with a rated control supply voltage / three-phase measuring voltage of 380 V AC and has a 2 c/o output with contacts rated at 250 V / 4 A. The CM-PSS.31S monitors the phase parameters over/undervoltage and phase failure. Phase sequence monitoring as well as an ON or OFF tripping delay are selectable. The tripping delay is adjustable over a range of instantaneous to 30 s (0, 0.1-30 s). A sealable transparent cover for protection against unauthorized changes is available as accessory. The device offers screw connection technology with double-chamber cage connection terminals.