Siemens 985L109442U Three Phase Thermal Overload Relay

Siemens 985L109442U is a three-phase thermal overload relay designed to protect motors in industrial control systems by interrupting current when overload conditions exceed the device's set range. It uses Trip Curve A and provides a protection window of 33-66 A across all three phases, enabling a defined, time-dependent response to overloads while accommodating typical startup transients. This unit is intended for inclusion in motor starter circuits with Siemens gear, helping to prevent motor damage by responding to overcurrent conditions in the protected range. The part number 985L109442U uniquely identifies this relay within Siemens' legacy overload-relay lineup, aiding maintenance and inventory tasks in Siemens-based control panels.