ABB RELION REX640 - 4.2 Earth-fault protection; 4.2.1 Non-directional earth-fault protection EFxPTOC (ANSI 51 G;51 N-1, 51 G;51 N-2, 50 G;50 N); 4.2.1.1 Identification; 4.2.1.2 Function block

4.1.12.10 Technical data
Table 501: GSLPTOC Technical data
Characteristics Value
Operation accuracy Depending on the frequency of the measured current f
n
±2 Hz
±1.5% of the set value or ±0.03 × I
n
Start time
1, 2
Typically 30ms
Reset time <30 ms
Reset ratio Typically 0.96
Retardation time <50 ms
Operate time accuracy ±1.0% of the set value of ±20 ms
4.2 Earth-fault protection
4.2.1 Non-directional earth-fault protection EFxPTOC (ANSI
51G/51N-1, 51G/51N-2, 50G/50N)
4.2.1.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Non-directional earth-fault protec-
tion, low stage
EFLPTOC Io> 51G/51N-1
Non-directional earth-fault protec-
tion, high stage
EFHPTOC Io>> 51G/51N-2
Non-directional earth-fault protec-
tion, instantaneous stage
EFIPTOC Io>>> 50G/50N
4.2.1.2 Function block
Figure 252: Function block
1
Current before fault = 0.0 x I
n
, f
n
= 50 Hz, nominal frequency fault current 1.1 x set Start value is
injected, results based on statistical distribution of 1000 measurements
2
Includes the delay (≈0ms) of the static signal output (SSO)
Protection functions 1MRS759142 F
440 REX640
Technical Manual