Contrel’s split core current transformers are made of an optimum quality magnetic core, which allows the detection of very low leakage currents. Each current transformer incudes a test winding, the test is conducted over the coupling between the relay and the transformer.
The relay sends a signal to the test winding. This signal generates a flow equivalent to a leakage, which is detected by the windings and sent back to the relay, and trips.
During the periodic tests, this verifies not only the relay but the integrity of the connections between the relay and the current transformer.
