Three-phase non-directional overcurrent protection (PHxPTOC) - 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. Three-phase non-directional overcurrent protection (PHxPTOC)
Characteristic Value
Operation accuracy Depending on the frequency of the measured current: f n ±2 Hz
PHLPTOC ±1.5% of the set value or ±0.002 × I n

PHHPTOC

and

PHIPTOC

±1.5% of set value or ±0.002 × I n

(at currents in the range of 0.1…10 × I n)

±5.0% of the set value

(at currents in the range of 10…40 × I n)

Start time 1, 2 Minimum Typical Maximum

PHIPTOC:

I Fault = 2 × set Start value

I Fault = 10 × set Start value

16 ms

11 ms

19 ms

12 ms

23 ms

14 ms

PHHPTOC and PHLPTOC:

I Fault = 2 × set Start value

23 ms

26 ms

29 ms

Reset time

Typically 40 ms

Reset ratio Typically 0.96
Retardation time <40 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
Operate time accuracy in inverse time mode

±5.0% of the theoretical value or ±20 ms 3

Suppression of harmonics

RMS: No suppression

DFT: -50 dB at f = n × f n, where n = 2, 3, 4, 5,…

Peak-to-Peak: No suppression

P-to-P+backup: No suppression

1 Set Operate delay time = 0,02 s, Operate curve type = IEC definite time, Measurement mode = default (depends on stage), current before fault = 0.0 × In, fn = 50 Hz, fault current in one phase with nominal frequency injected from random phase angle, results based on statistical distribution of 1000 measurements
2 Includes the delay of the signal output contac
3 Includes the delay of the heavy-duty output contact