Earth Continuity Protection Relay

A01366 earth continuity relay non i s.

Earth continuity protection relay.

An earth continuity relay is designed to provide earth continuity protection. To protect against a short circuit of the pilot conductor to earth a 235 ohm resistor is connected in the. The control interface is the central unit of the epoch protection system and is the integral component that brings together the full protection functionality to each outlet. The ic3 utilises microprocessor technology to provide a greater level of stability over longer pilot cables by using digital filtering techniques.

I c3 download datasheet combined protection relays a00622b earth leakage earth continuity relay elec download datasheet. Earth continuity failure protection. The bramco ic3 earth continuity relay is designed to actively monitor the resistance of the pilot earth cir cuit in a supply cable by diode termination. Earth leakage relays perform two main functions on mining installations.

It performs the as nzs 2081 2011 earth continuity protection function on the outlet as well as receive and process the signals from the power interface. The method used is called pilot earth loop or earth continuity monitoring where an additional core pilot cable is included with the power and earth cores in the trailing or reeling cables which supply power to the machines. The ecm2 relay continually monitors the earth continuity of a mining trailing cable. The bramco electronics earth continuity relay model i c has been designed to monitor the continuity of the earth cir cuit in a supply cable by grounding the pilot core via a diode polarized positive to earth.

The ecm2 relay is normally installed in a substation or a distribution box to provide earth continuity protection. Meanwhile both as nzs2081 and as nzs4871 require that the earth continuity protection should also be capable of monitoring incremental changes in the resistance of the earth return path to ensure. In the typical distribution circuit shown in fig 1 an earth leakage relay provides protection against leak age to earth and earth faults. We took a fresh look at earth continuity safety and as nzs2081 compliance to design a new method of earth continuity protection that utilises a trip curve to discriminate between earth disconnection faults and incremental increases in the earth return impedance.

As nzs2081 requires that earth continuity protection be capable of operating within 100ms to quickly protect an outlet in case of live uncoupling. When short circuit between the pilot and earth cores in the trailing cable completes the circuit through the operating relay and if the pilot circuit were not to fail to safety such a fault would cause the motor to start immediately.