Description
The Siemens Industrial Controls 3RU2126-1HB0 Thermal Overload Relay is a bimetallic current-sensing relay with a screw terminal connection and an adjustable trip range in the frame size, used to protect motors from damage caused by sustained overcurrent that exceeds the rated full-load amperage. It tracks current draw across each phase and trips the output contact when accumulated heat within the sensing strip reaches the level corresponding to the dialed current setting. Within HVAC systems, the screw terminal configuration allows direct wiring into the motor control panel, where the relay safeguards fan, pump motors, and air handler drives from prolonged thermal strain.
