Restricted Earth Fault Relay
Product Details
Product Glance
The DIGITAL MICROPROCESSOR BASED RESTRICTED EARTH FAULT RELAY (REFR), is a universal protection device for high, medium and low voltage networks. It is aimed primarily at high impedance differential schemes such as restricted earth fault and generator differential protection.
In this type of protection scheme, based on circulating current measurement, heavy through fault currents during a fault condition can cause current transformers to approach or exceed their saturation level and allow sufficient unbalance current to operate the relay. This is due to the asymmetrical current of extreme magnitude which has dissimilar effects on seemingly identical CT's.