Description
The Siemens Industrial Controls 3RU2126-1KB0 Thermal Overload Relay is a current-sensing protective relay with an adjustable trip range of 9 to 12.5 amperes, used to guard motors against damage caused by sustained overcurrent conditions that exceed the motor’s rated full-load amperage. The output contact breaks when heat buildup within the bimetallic sensing strip reaches the threshold corresponding to the set current value. Within HVAC systems, this relay mounts directly onto a compatible contactor in the motor control circuit of fan motors, pump motors, and compressor starters, cutting the control circuit before winding insulation shuts down from excessive thermal pressure.
