ABB 1MRK002826-AG - Page 100

Table 80. General current and voltage protection CVGAPC, continued
Function Range or value Accuracy
Impulse margin time 15 ms typically -
Undervoltage:
Critical impulse time 10 ms typically at 1.2 x U
set
to 0.8 x
U
set
-
Impulse margin time 15 ms typically -
SEMOD175176-2 v5
Table 81. Rotor earth fault protection based on General current and voltage protection (CVGAPC) and RXTTE4
Function Range or value
For machines with:
• rated field voltage up to 350 V DC
• static exciter with rated
supply voltage up to
700 V 50/60 Hz
Supply voltage 120 or 230 V 50/60 Hz
Operate earth fault resistance
value
Approx. 1–20 kΩ
Influence of harmonics in the
DC field voltage
Negligible influence of 50 V,
150 Hz or 50 V, 300 Hz
Permitted leakage capacitance (1–5) μF
Permitted shaft earthing
resistance
Maximum 200 Ω
Protective resistor 220 Ω, 100 W, plate
(the height is 160 mm (6,2
inches) and width 135 mm (5,31
inches))
Generator protection REG670
1MRK 502 074-BEN M
Version 2.2
100 Hitachi Power Grids
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