Siemens 3RU2126-4BB0 Thermal Overload Relay Module

Siemens Sirius 3RU2126-4BB0 is a thermal overload relay designed for motor protection, sized for S0 mounting and compatible with Siemens 3RU2 contactors. It provides current-dependent overload protection for motors in the 14 to 20 A range and includes a manual-automatic reset with auxiliary contacts (1NO + 1NC) for status signaling; main circuit and auxiliary circuit use screw terminals. The device offers front IP20 protection, insulation voltage up to 690 V, and a typical power loss of 6.2 W, with an operating temperature range of -40 to +70 C and up to 90% relative humidity during operation. This overload relay is intended to be mounted on a compatible contactor and is part of the Sirius motor-protection line for reliable thermal protection of three-phase motors.