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CT scaling: current transformer ratio.
Example: a 250A / 5A CT has a CT Scaling of 50.
C/k: starting current of the RVT Controller. It is usually set equal to 2/3 of the current of the capacitor step (Qstep)
(see paragraph 4.3.1.1.)
It represents the threshold current value for the RVT to switch ON or OFF a capacitor step. The C/k can be pro-
grammed from 0.01 to 5.
The following example shows the effect of a too low C/k value and how it can lead to useless switching:
A too high C/k value will lead to insufficient capacitor steps being switched ON in order to reach the target cos .
The recommended setting of C/k can be calculated by the following formula or can be read directly in the table below.
Formula
Three phase network
CT ratio
10/1
50/5
20/1
100/5
30/1
150/5
40/1
200/5
STATUS
Approved
Figure 36 RVT installation settings
Table 2 C/k table for a 3-phase balanced 400V system
K
5
10
15
10
0.48
0.97
1.45
20
0.24
0.48
0.73
30
0.16
0.32
0.48
40
0.12
0.24
0.36
SECURITY LEVEL
Public
PO WER FACTO R CON TR O LL ER RV T
Single phase (L-L or L-N) network
20
30
40
50
1.93
2.90
3.87
4.84
0.97
1.45
1.93
2.42
0.64
0.97
1.29
1.61
0.48
0.73
0.97
1.21
DOCUMENT ID
9AKK107045A9645
Capacitor step rating (kvar)
60
70
90
100
2.90
3.38
4.35
4.84
1.93
2.26
2.90
3.22
1.45
1.69
2.18
2.42
REV.
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120
3.87
2.90
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