Dold Thermistor Motor Protection Monitoring Relay, SPDT, DIN Rail

1 input for thermistors or bi-metallic contacts
Wire breakage detection in the sensor circuit
LED for switching status
Rest current principle
1 changeover
22.5 mm overall width

The MK9052 motor protection relay is used to prevent thermal overloads in motors (for example as caused by high switching frequencies, heavy start-up loads, single phase operation, interrupted cooling, high ambient temperature).
Special thermistors (PTC resistors) developed specifically for motor protection are used as temperature sensors. Up to 6 sensors can be switched in sequence; when a fixed resistance level is reached, they cause the output relay of the MK9052 to de-energise.