Wye ∆2 – Basler Electric BE1-87T User Manual
Page 74
4-32
BE1-87T Installation
9171300990 Rev V
Figure 4-35. Three-Phase Connections, Autotransformer With Loaded Delta Tertiary
The transformer in the example shown in Figure 4-34 has a delta connection on the tertiary winding. The
currents in each winding of the delta are A, B, and C respectively as reflected from the wye or auto
connected winding. The delta connection of the transformer windings causes the current flowing in the
phase leads connected to the delta winding to be A-B, B-C and C-A respectively. The CT currents on the
wye or auto windings must be combined similarly to provide A-B, B-C and C-A to compensate. This is
shown in Figure 4-34 by selecting phase compensation jumper position ∆2 for these inputs. This also
provides zero sequence blocking for these inputs since this transformer configuration is a source of zero
sequence currents.
H
2
H
1
H
3
C
B
A
Switch
board
terminal
blocks
D2751-27.vsd
09-07-00
Y
2
Y
1
Y
3
C
B
A
16 17
18
15
12
14
13
11
∆2
X
3
X
2
X
1
C
B
A
6
7
2
5
BE1-87T
WYE
∆2
PHASE COMPENSATION JUMPER POSITION ON ANALOG BOARD #2.
Y
1
X
2
Y
3
H
2
H
1
X
1
H
3
X
3
H
0
X
0
Y
2
H
0
X
0
B
C
A