Schneider Electric’s Square D CC81.5 Thermal Unit is a one‑piece overload protection accessory for C Series contactors, rated for 49.1 to 61.2 A in 600 V AC systems and designed to shield motors, controllers, and branch‑circuit conductors from overheating during prolonged overloads. The unit uses a heater winding and a melting alloy mechanism; under overload, the solder melts to release a ratchet that opens the control circuit and disconnects the motor contacts. Classified as a Class 20 thermal unit, CC81.5 typically trips in 20 seconds or less when overload occurs, providing reliable motor protection in CC contactor installations.
