Use of Faulted Phase Earthing using a custom built earth fault controller

In order to reduce customer hours lost (CHL) and customer interruptions (CI), the use of Faulted Phase Earthing (FPE) is being considered on the Irish 20 kV distribution system. The operation of this particular FPE system is enabled by the use of a custom built Earth Fault Controller (EFC) that has the ability to detect high impedance faults of up to 12 k??. The EFC can also successfully identify single pole switching events, which have at times caused the mal-operation of existing protection. FPE involves the earthing of a faulted phase during a single line to ground fault. This ensures that the fault site is made safer and that no customers are interrupted during the fault.