ABB RELION REX640 - 4.3 Differential protection; 4.3.1 Line differential protection with in-zone power transformer LNPLDF (ANSI 87 L); 4.3.1.1 Identification; 4.3.1.2 Function block

4.2.10.9 Technical data
Table 644: IFPTOC Technical data
Characteristics Value
Operation accuracy Depending on the frequency of the measured current f
n
±2 Hz
Earth-fault current and touch voltage:
±1% of the set value or ±0.005 × I
n
for
Accuracy of follows accuracy.
Residual voltage:
±1.5% of the set value or ±0.002 × U
n
Residual current:
±1.5% of the set value or ±0.002 × I
n
(at currents ≤10 x I
n
, when Uo is nominal)
±5.0% of the set value (at currents > 10 x I
n
)
Start time
1
Typically 30 ms
Reset time <30 ms
Reset ratio Typically 0.96
Retardation time <50 ms
Operate time accuracy
±1.0% of the set value or ±20 ms (DT)
±3% of the theoretical value or ±40 ms (IDMT)
4.3 Differential protection
4.3.1 Line differential protection with in-zone power
transformer LNPLDF (ANSI 87L)
4.3.1.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Line differential protection with in-
zone power transformer
LNPLDF 3Id/I> 87L
1
Measured with static signal output (SSO)
1MRS759142 F Protection functions
REX640
Technical Manual
643