Stabilized and instantaneous differential protection for two-winding transformers (TR2PTDF) - 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. Stabilized and instantaneous differential protection for two-winding transformers (TR2PTDF)
Characteristic Value
Operation accuracy Depending on the frequency of the measured current: f n ±2 Hz
±3.0% of the set value or ±0.002 × I n
Start time

Minimum

Typical

Maximum

Low stage

High stage

36 ms

21 ms

41 ms

22 ms

46 ms

24 ms

Reset time Typically 40 ms
Reset ratio Typically 0.96
Suppression of harmonics DFT: -50 dB at f = n × f n, where n = 2, 3, 4, 5, …
1 Current before fault = 0.0, f n = 50 Hz, results based on statistical distribution of 1000 measurements
2 Includes the delay of the output contact. When differential current = 2 × set operate value and f n = 50 Hz.