Rotor earth-fault protection (MREFPTOC) - Arc protection - Merging unit - Motor protection - Product Guide - REM620 Motor Protection and Control - Relion 615 series - 2.0 FP1 IEC - IEC - 01.06.2023

REM620 Product Guide

Table 1. Rotor earth-fault protection (MREFPTOC)
Characteristic Value
Operation accuracy Depending on the frequency of the current measured: fn ±2 Hz
±1.5% of the set value or ±0.002 × In
Start time 1, 2 IFault = 1.2 × set Start value Minimum Typical Maximum
30 ms 34 ms 38 ms
Reset time <50 ms
Reset ratio Typically 0.96
Retardation time <50 ms
Operate time accuracy ±1.0% of the set value of ±20 ms
Suppression of harmonics -50 dB at f = n × fn, where n = 2, 3, 4, 5,…
1 Current before fault = 0.0 × In, fn = 50 Hz, earth-fault current with nominal frequency injected from random phase angle, results based on statistical distribution of 1000 measurements
2 Includes the delay of the signal output contact