U-EK230E

The U-EK 230E is a thermistor motor protection device which is intended for use in conjunction with a contactor for the protection of the Ex fans with integrated PTC (Positive Temperature Coefficient) protective circuits. It is an electronic unit that is designed for snap fitting onto a 35 mm instrument rail (DIN rail). Fan motors have six series-connected thermistors, two per phase winding, whose resistance is determined by the motor temperature. If the motor temperature exceeds the permitted limit the resistance rises sharply and the motor protector is triggered. Once this has been triggered a warning light is illuminated. 

In case of failure, the relay switches off the contactor/circuit breaker and so prevents an overheating of the isolation system and/or the surface temperature. The protective function of the equipment is guaranteed only if wiring is done directly into the control circuit of the motor/machine in accordance with the connection diagram.