18
Inverse time
characteristic
T1: The first delay time to start, when the meas-
ured voltage exceeds or falls below the limit
value.
T2: The second delay time to start, when the
first voltage regulation fails.
Both T1 and T2 can be given definite time char-
acteristic or inverse time characteristic. The
minimum time at inverse time characteristic is
1 s, even though T1 and T2 have the setting 0 s.
The inverse time function is defined by the fol-
lowing expression :
B =
t =
where
U
d
= U
m
- U
p
, differential voltage
∆
U
s
= bandwidth
T
= T1 or T2
U
d
∆
U
s
T
2
(B-1)
Fig. 5. Time characteristics of the automatic voltage regulating module SPCU 1D50
Technical data
Delay time setting range
0.0...300 s
Operate time accuracy at definite time
±
1% of set value or
±
250 ms
characteristic
Operate time accuracy at inverse time
±
250 ms and the inaccuracy appearing,
characteristic
when the measured voltage varies
±
0.4%
Minimum operate time at inverse time
characteristic
1 s
Minimum values at which the phase shift
0.04 x I
n
calculation is enabled
0.05 x U
n
0
50
100
150
200
250
300
0
T1,T2
300
150
120
90
60
30
1
2
3
4
5
6
7
8
B
