ABB RET630 - High-Impedance Based Restricted Earth-Fault Protection

Table 37. 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
1)2)
I
Fault
= 2.0 × set
Operate value
I
Fault
= 10.0 × set
Operate value
Typical 22 ms (±5 ms)
Typical 15 ms (±5 ms)
Reset time < 40 ms
Reset ratio Typical 0.96
Retardation time < 35 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
Table 38. High-impedance based restricted earth-fault protection (HREFPDIF) main
settings
Parameter
Function Value (Range) Step
Operate value HREFPDIF 0.5...50.0 % 0.1
Minimum operate
time
HREFPDIF 0.020...300.000 s 0.001
Transformer Protection and Control 1MRS756788 A
RET630
Product version: 1.0 Issued: 15.09.2009
ABB 33