ABB RET670 - Page 55

Table 26. Additional security logic for differential protection LDRGFC
Function Range or value Accuracy
Operate current, zero sequence current (1-100)% of lBase ±1.0% of I
r
Operate current, low current operation (1-100)% of lBase ±1.0% of I
r
Operate voltage, phase to neutral (1-100)% of UBase ±0.5% of U
r
Operate voltage, phase to phase (1-100)% of UBase ±0.5% of U
r
Independent time delay, zero sequence current at 0 to 2 x I
set
(0.000-60.000) s ±0.2% or ±40 ms
whichever is greater
Independent time delay, low current operation at 2 x I
set
to 0 (0.000-60.000) s ±0.2% or ± 40 ms
whichever is greater
Independent time delay, low voltage operation at 2 x U
set
to 0 (0.000-60.000) s ±0.2% or ±40 ms
whichever is greater
Reset time delay for startup signal at 0 to 2 x U
set
(0.000-60.000) s ±0.2% or ±40 ms
whichever is greater
Transformer protection RET670 2.0
1MRK 504 141-BEN C
Product version: 2.0
ABB 55