ABB REG670 Applications Manual page 430

Section 10
Voltage protection
424
Table 47: Settings
U/f op (%) Timer
105 t1
112 t2
119 t3
126 t4
133 t5
140 t6
Information on the cooling time constant T
transformer manufacturer.
V/Hz
%
150
140
130
120
110
100
0.05 0.1 0.2 0.5
t6 t5 t4
IEC01000377 V1 EN
Figure 209: Example on overexcitation capability curve and V/Hz protection
settings for power transformer
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Time set (s)
7200 (max)
600
60
20
8
4
should be retrieved from the power
cool
transformer capability curve
relay operate characteristic
1 2 5 10
t3 t2
1MRK 502 071-UEN -
Continous
20 50 100 200
(minutes)
t1
en01000377.vsd
Application manual
Time