Dc Earth Leakage Relay

The el731 ac dc sensitive earth leakage relay is a revolutionary product that finally solves common ground fault problems associated with variable frequency drives and is equally applicable to ac dc and mixed ac dc systems.

Dc earth leakage relay.

The measuring method is based on the principle that the positive and the negative current in a fault free load circuit sum to zero. The el731 is a microprocessor based ac dc sensitive earth leakage relay that offers complete coverage for all frequencies from 0 6 000 hz. It detects a wide range of earth leakage currents and can reliably protect a variety of applications including conveyor. Thus leakage current if any will be dependent on the resistance value between respective terminals higher the resistance lower is the leakage.

The dc leakage current is measured by electronic ag sensor inserted in each monitored load circuit. Unlike potential based sensors these sensors can localize the earth leakage fault to specific feeders if the feeder cables are passed through the sensor unit. The relay senses the dc earth leakage current for any equipments like switch boards rectifiers battery chargers by sensing resistance between positive negative terminals of dc system earth. Two ct s are required for the entire frequency range or one ct can be used for only low or high frequency detection.

Thus leakage current if any will be dependent on the resistance value between respective terminals higher the resistance lower is the leakage. These relays are ideal for detecting and localizing earth leakage in dc power systems. The relay senses the dc earth leakage current for any equipments like switch boards rectifiers battery chargers by sensing resistance between positive negative terminals of dc system earth.