Megger TTR310 - Page 52

M
AVTMTTR310 Rev 8 May 2016
40
Table 5-4. ANSI Transformer Winding Phase Relationship
Copyright 2009  Megger
Winding Connection Winding Tested
Diag
No.
IEC
Vector
Group
High-Voltage
Winding (H)
Low-Voltage
Winding (X)
Phase
Tested
Winding
Shorted
By TTR
High-
Voltage
Winding
Low-
Voltage
Winding
Measured
Turn Ratio
Remarks
20
Yyn0
A+C
B+A
C+B

H
1
- H
3
H
2
- H
1
H
3
- H
2
X
1
- X
3
X
2
- X
1
X
3
- X
2
V
V
H
X
No
accessible
neutral on
high-voltage
winding
21
Yy0
A
B
C

H
1
- H
3
H
2
- H
1
H
3
- H
2
X
1
- X
3
X
2
- X
1
X
3
- X
2
V
V
H
X
No
accessible
neutral both
wye windings
22
YNy6
A
B
C
H
2
- H
0
H
3
- H
0
H
1
- H
0
H
1
-(H
2
-H
0
)
H
2
-(H
3
-H
0
)
H
3
-(H
1
-H
0
)
X
2
- X
1
X
3
- X
2
X
1
- X
3
V
V
H
X
No
accessible
neutral on
low-voltage
winding
23
Yyn6
A+C
B+A
C+B

H
1
- H
3
H
2
- H
1
H
3
- H
2
X
3
- X
1
X
1
- X
2
X
2
- X
3
V
V
H
X
No
accessible
neutral on
high-voltage
winding
24
Yy6
A+C
B+A
C+B

H
1
- H
3
H
2
- H
1
H
3
- H
2
X
3
- X
1
X
1
- X
2
X
2
- X
3
V
V
H
X
No
accessible
neutral on
both wye
windings
25
Yzn1
A
B
C

H
1
- H
3
H
2
- H
1
H
3
- H
2
X
1
- X
0
X
2
- X
0
X
3
- X
0
V
V
H
X
v 3
No
accessible
neutral on
wye winding