High-impedance based restricted earth-fault protection (HREFPDIF) - Arc protection - Merging unit - Transformer protection - 2 winding - Product Guide - RET615 Transformer Protection and Control - Relion 615 series - 5.0 FP1 IEC - IEC - 24.05.2023

RET615 Product Guide

Table 1. High-impedance based restricted earth-fault protection (HREFPDIF)
Characteristic Value
Operation accuracy At the frequency f = f n
±1.5% of the set value or ±0.002 × I n
Start time

I Fault = 2.0 × set Operate value

I Fault = 10.0 × set Operate value

Typically 22 ms (±5 ms)

Typically 15 ms (±5 ms)

Reset time <60 ms
Reset ratio Typically 0.96
Retardation time <60 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
1 Current before fault = 0.0 × I n, f n = 50 Hz
2 Includes the delay of the signal output contact