ABB 1MRK002826-AG - Page 88

GUID-A1CB5B4F-768E-4B1B-937E-B91EC3EFA2CC v4
Table 67. Generator rotor overload protection GRPTTR
Function Range or value Accuracy
Overcurrent start level for overload
protection
(105.0–900.0)% of IBase ±1.0% of I
r
at I ≤ I
r
±1.0% of I at I > I
r
Reset ratio, overcurrent >95% —
Start time, overcurrent at 0 to 2 x
I
set
Min = 50 ms —
Max = 170 ms
Thermal time characteristic According to
IEEE Std C50.13–2005
±1.5% or ±200 ms whichever is greater
Minimum operate time for thermal
characteristic
(1.0–120.0) s ±1.5% or ±200 ms whichever is greater
Maximum operate time for thermal
characteristic
(100.0–2000.0) s ±1.5% or ±200 ms whichever is greater
Undercurrent start level (5.0–500.0)% of IBase ±1.0% of I
r
at I ≤ I
r
±1.0% of I at I > I
r
Start time, undercurrent at 2 x I
set
to 0
Min = 15 ms —
Max = 30 ms
Independent time delay for
undercurrent function at 2 x I
set
to
0
(0.0–600.0) s ±0.2% or ±45 ms whichever is greater
Generator protection REG670
1MRK 502 074-BEN M
Version 2.2
88 Hitachi Power Grids
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