Megger TTR310 - Additional Winding Identification

M
AVTMTTR310 Rev 8 May 2016
36
Additional Transformer Winding Identification
External terminal markings for three-phase power transformers with more than
two windings are as follows:
Y
1
, Y
2
, Y
3
Third winding (if any).
Z
1
, Z
2
, Z
3
Fourth winding (if any).
If unable to find a corresponding diagram for a transformer with, for example,
accessible neutral winding but can find the corresponding diagram for the same
transformer with no neutral accessible winding, follow the test procedure for the
transformer with no neutral accessible winding. In this case, specify the diagram
number for the transformer with no neutral accessible winding and do not
connect H0 or X0 lead to the neutral. Note that on the print out of the results,
the vector designation and the corresponding diagram will not be EXACT, but
will be close to the actual transformer configuration.
As an example, if transformer winding connection is identical to Table 5-4
Diagram No. 26 except the wye winding has an accessible neutral winding,
perform test per Diagram 26. Do not connect H0 lead to the wye winding
neutral terminal. The test results are identical and do not require any corrections.
Note that on the print out of the results, the vector designation and the
corresponding diagram will not be EXACT, but will be close to the actual
transformer configuration.