1SVR730700R2200

The ABB 1SVR730700R2200 (CM-MSS.23S) is a high-quality thermistor motor protection relay designed to monitor motor winding temperatures and help protect industrial electric motors against overheating. Manufactured by ABB, this relay belongs to the CM-MSS series of motor temperature monitoring relays and operates with rated control supply voltages of 110–130V AC or 220–240V AC. It features two changeover (SPDT) output contacts rated at 250V and 4A, providing flexible switching capability for industrial motor protection circuits. The relay includes one sensor circuit for monitoring compatible PTC thermistors installed inside motor windings, making it suitable for industrial machinery, electrical control panels, and automation systems.

The ABB CM-MSS.23S thermistor motor protection relay continuously monitors the resistance of connected PTC temperature sensors. When the motor winding temperature reaches the sensor's specified response temperature, the sensor resistance increases and the relay detects the overheating condition. Its output contacts change state, enabling a correctly designed control circuit to disconnect or inhibit motor operation. The relay works according to the closed-circuit principle and supports automatic, manual, or remote reset once the fault condition has cleared.