Protection functions

REJ603 offers three-stage overcurrent and twostage earth-fault protection functions.

The transformer inrush detector function is incorporated to prevent unwanted tripping’s due to energizing of transformers.

The low-set stages for overcurrent and earthfault protection are equipped with selectable characteristics – Definite time (DT) and Inverse

definite minimum time (IDMT).

The relay featuresstandard IDMT characteristics according IEC 60255-151. Normal Inverse (NI), Very Inverse (VI),

Extremely Inverse (EI), Long-time Inverse (LI) and IDMT characteristics as per ANSI C37.112 Moderate inverse,

Normal Inverse, Very inverse, Extremely inverse.

The relay also has special characteristics like RI, HR and FR fuse,which allows better co-ordination with the rest of the network.

Further relay offers thermal overload protection for feeder, cable and transformer.