Megger DELTA4000, Instruction Manual, Page: 30 / 74

M
AVTMDELTA4000-EN Rev 6 April 2018
22
Setup
The following steps are a general guide for setting up the test set. Figure 4 shows
a typical setup for testing inter-winding and ground capacitance on a three-phase
delta-wye power transformer; Figure 5 shows a typical setup for making
excitation current measurements on the same transformer. The test set controls
and connectors are identified in Figures 1 through 3. Refer to the Application
Guide for specific instructions on connecting this and other power equipment to
the test set.
When making capacitance measurements on transformer windings always short
each winding on itself with a jumper lead to eliminate winding inductance effect.
The shorting wire is usually non-insulated and must not be in contact with any
other insulated or non-insulated parts of the transformer.
When making transformer excitation current measurements conduct all tests on
high-voltage windings only. This reduces the required charging current. In load
tap changers, set to fully raised or fully lowered position for routine tests.
F
WARNING
There is always the possibility of voltages being
induced at the terminals of a test specimen because
of proximity to energized high-voltage lines or
equipment. A residual static voltage charge may also
be present at these terminals. Ground each terminal
to be tested with a safety ground stick, then install
safety ground jumpers, before making connections.