ABB Relion 630 Series RET630 Product Manual page 54

Transformer Protection and Control
RET630
Product version: 1.1
Table 78. Tap changer control with voltage regulator (OLATCC)
Characteristic
1)
Operation accuracy
Operate time accuracy in definite time mode
Operate time accuracy in inverse time mode
Reset ratio for control operation
Reset ratio for analogue based blockings (except run back
raise voltage blocking)
1) Default setting values used
2) Default setting values used
3) Default setting values used
54
Value
Depending on the frequency of the current measured: fn ±2
Hz
Differential voltage Ud
Operation value
2)
3)
1MRS756978 D
Issued: 2011-05-18
± 1.0% of the measured value
or ± 0.004 x Un (in measured
voltages < 2.0 x Un)
± 1.0% of the Ud or ±0.004 x
Un for Us = 1.0 x Un
± 1.0% of the set value or
0.11 seconds
± 15.0% of the set value or
0.15 s
(at theoretical B in range of
1.1...5.0) Also note fixed
minimum operate time
(IDMT) 1 s
Typical 0.80 (1.20)
Typical 0.96 (1.04)
ABB