1SVR740700R2200

The ABB 1SVR740700R2200 (CM-MSS.23P) 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 functionality for industrial motor protection circuits. The relay includes one sensor circuit for monitoring compatible PTC temperature sensors installed inside motor windings, making it suitable for industrial machinery, electrical control panels, and automation systems.

The ABB CM-MSS.23P continuously monitors the resistance of connected PTC thermistors to detect abnormal motor winding temperature conditions. When the motor temperature reaches the sensor's specified response threshold, the relay changes its output contact state, allowing a correctly designed motor control circuit to disconnect or inhibit motor operation. It operates according to the closed-circuit principle and supports automatic, manual, or remote reset after the fault condition has cleared.