<< Click to Display Table of Contents >> Navigation:  Components and parameters > Switches and protections > Earth fault differential

A restricted earth fault (REF) protection or earth fault differential protection serves for fast, sensitive and directional protection of a transformer or machine in case of an earth fault in the windings. The restricted earth fault protection is coupled to one circuit breaker and one element or transformer with an grounded neutral point. The sum of the currents through the circuit breaker and the sum of the currents at the point of connection of an element or transformer is used for the equation, instead of the real current through the neutral point. It is possible to define additional circuit breakers that will be tripped using the transfer trip ability (which can be specified at the level of the circuit breaker, not in the specific protection function tabs).

 

 

Parameters