Baker D30R, User'S Manual & Operating Instructions

Page: 103 / 142

D30R Users Manual
103
Do Not Touch Test Leads while test is in Progress!
71-023 Rev C 5/8/2007
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The surge test circuit will be loaded by the feeder cable capacitance as
well as the motor. Significantly higher Output settings will be needed
to reach the required test voltage. If the surge tester is too small to
handle both the cable and the motor load, a trace will be observed but
the proper test voltage will not be reached. A higher output surge tester
model will be required or the motor may have to be tested while
disconnected from the feeder cable.
There is no precise science to determine what size motor, with what
size and length feeder cable a particular surge test model can
adequately test. In general, the closer the size of the motor is to the
recommended maximum motor size for a given model surge tester, the
shorter the cables can be and still allow testing at the required voltage.
Conversely, the smaller the motor size, the longer the cable can be.
Transformers
Transformers contain similar insulation systems as motors: ground, turn-to-turn
and phase insulation. However, the spectrum of winding characteristics for
transformers is much broader than for motors.
The Surge test is only one of many tests that should be performed to properly
test a transformer. If the transformer has thousands of turns, the surge tester
may not be sensitive enough to detect a single shorted winding. It may also
sense the high inductance of a transformer as an open.
The following procedures for single phase and three phase transformers provide
the basics necessary to surge test transformers. Please call Baker Instrument
Company at 800-752-8272 for further assistance or if difficulties are
encountered when testing transformers.
Single Phase Transformers
1. Jumper (or short out) the secondary side (low side) of the transformer.
2.
Select TLS #1. Follow the diagram below to connect test lead #1 to H1
and to H2 of the transformer. The black GRD lead and test lead #3 go
to the frame.