Three-phase monitoring relay – Functional monitoring in buildings, on machines, and in systems, PFD2-E12, 400 V AC, 2 changeover contacts

The monitoring relay is used to monitor the correct phase sequence L1-L2-L3 (clockwise rotation) and to monitor the individual phase voltages for total failure. The phase voltages to be monitored are connected to terminals L1-L2-L3; terminals 11, 14, or 21, 24 of the relay output contacts are connected upstream of the excitation coil of the motor contactor. If the phase sequence is correct, the output relay switches on (green LED on). In the event of a total phase failure, the output relay returns to its rest position (green LED off). A separate supply voltage for the monitoring relay is not required. The device must only be connected to N if the three phases to be monitored are connected to N via a circuit (e.g., temperature monitoring or similar).