SKF AWAIV-12, User Manual, Page: 158 / 250

Three-phase transformers
It is beyond the scope of this manual to cover all possible transformer connections. It is
important to remember that you must surge test each line high side connection point to the
other end of its own coil, and that the secondary side of the coil being surged must be
shorted out (with jumpers connected together and to ground).
NOTE
A wye-wye transformer with the star point internally tied can be surge tested
without opening the tie point.
1) Use test lead No. 1.
2) Connect the black ground test (GND) lead to the frame (ground) of the transformer.
3) Follow one of the charts below for connections for wye-wye or delta-wye
transformers. You should surge test the transformer windings for all the
configurations shown.
4) Test procedures follow identically as for single-phase transformer testing (refer to
single-phase motors and two-terminal devices).
Table 5. Wye-wye transformers.
Test Lead No. 1 Test Lead No. 2 Jumper
H1 H0 X0 to X1
H2 H0 X0 to X2
H3 H0 X0 to X3
Table 6. Delta-wye transformers.
Test Lead No. 1 Test Lead No. 2 Jumper
H1 H2 X0 to X2
H1 H3 X0 to X1
H2 H1 X0 to X2
H2 H3 X0 to X3
H3 H2 X0 to X3
H3 H1 X0 to X1
Determining a fault
The determination of a fault when surge testing a transformer winding follows that of the
two-terminal device (refer to single-phase motors and two-terminal devices).
144 SKF Static Motor Analyzer—Baker AWA-IV User Manual
Motor testing theory and reference