Basler Electric BE1-87T - Manual (Page 72)

4-30 BE1-87T Installation 9171300990 Rev V
Figure 4-33. Three-Phase Connections, Wye-Wye or Autotransformer Configuration, CT Compensation
The Wye-Wye or Autotransformer does not require phase shift compensation. However, it is necessary to
Delta compensate the currents to block zero sequence currents being supplied by the transformer bank.
This is shown in Figure 4-32 by connecting the CTs in Delta. In Figure 33, compensation is shown by
internal phase compensation jumper setting.
H
2
H
1
H
3 C
B
A
Switch
board
terminal
blocks
H
3
H
2
H
1
X
1
X
2
X
3
D2751-25
04-16-99
1
H
0
, X
0
, OR H
0
X
0
BUSHING, AS
APPROPRIATE
H
0
H
2
H
1
X
1
H
3
X
3 H
0
X
0
OR
X
2
X
1
X
3 C
B
A
16
17
18
15
12
14
13
11
WYE
WYE
BE1-87T
1 C
B
A
N
B
C
N
A
(WITH UNLOADED TERTIARY)
1 AN ALERNATIVE TO GROUNDING THE CORNER OF THE THE DELTA CONNECTED CTs
IS TO CONNECT THE GROUND TO LEADS CONNECTED TO TERMINALS 13 AND18.
2
2 IF THERE IS NOT A DELTA TERTIARY, OR IF THE WYE WINDING IS UNGROUNDED, IT IS
UNNECESSARY TO DELTA SHIFT THE CURRENTS FOR ZERO SEQUENCE BLOCKING.
NOTES:
X
2
Phase shift jumper
position on analog
board #2.
B
C A