Earth Leakage Protection & Measurement Transformers for Low Voltage
- To be used with ELR-B, ELR-3C, D30 and DM30 relays.
- The transformer and relay assembly sensitivity is fixed by the relays
Type Code Core Inner ø Weight(kg.) CT-1 / 160 41080 Closed 160mm 1,4 - Working principles: The toroidal transformer is installed between the source and the load. The system works on the current balance principle. In a correct installation the vector sum of the currents is zero and the relay will not trip.
In case of an insulation fault on the circuit a leakage current flows to earth. Now the vector sum of the current passing through the transformer is not zero, this imbalance is detected by the transformer, which induces a current in the secondary winding which is connected to the relay.