ABB 615 series Technical Manual page 478

Section 4
Protection functions
472
A B C
P2
S2
S1
P1
P2
S2
S1
P1
A B C
GUID-75245AA5-315C-4018-95E3-FEEC1D1CD4B3 V1 EN
Figure 231: Connection example of current transformers of Type 2
Transformer vector group matching
Before differential and bias currents can be calculated, the phase difference of the currents
must be vector group matched based on the transformer connection type. The vector group
X120
1/5A
7
IA
N
8
1/5A
9
IB
10 N
11 1/5A
IC
12
N
X120
7 1/5A
IA
8
N
9
1/5A
IB
10
N
11
1/5A
IC
12
N
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615 series ANSI
Technical Manual