5
Overhead Applications
Such typical components as capacitors, transformers, potheads, terminations
and insulators can be tested with the PT-5000W as shown here.
Transformers can be tested to verify insulation between both primary and secondary
windings. For two bushing transformers connect the tester from either primary bushing
to ground and select the 5,000VDC range. Single primary bushing transformers cannot
be tested here.
Test transformer secondary insulation to ground only when the secondary center
tap has been ungrounded. Select the 500VDC range.
Test insulation from primary winding to secondary winding as shown here.
Select the 500VDC range.
Test capacitor insulation to ground on two bushing capacitors as shown. Select
the 5,000VDC range for typical primary voltage power factor correction capacitors.
Testing across the two bushings of a two bushing capacitor or from bushing to ground on
a one bushing capacitor will place a substantial charge on the capacitor and the PT-5000W
will indicate leakage current until the capacitor is fully charged. Because of the built in 30
second time limit, capacitors tested in this manner can only be charged up to 500VDC and
should only be tested with the 500VDC range. Remember that the tester requires up to 2
minutes to fully discharge a charged capacitor and should remain connected for that time.
Underground Applications
Underground insulation systems include a wide variety of cable and equipment and
almost any insulating system or component can be tested with the PT-5000W. Secondary
voltage systems should be tested only with the 500VDC range except some direct bury
secondary cables with higher test voltages can be tested on the 5,000VDC range. Consult
the cable supplier for more information.
Pad mount transformers can be tested with the same connections as shown for overhead
transformers as shown for overhead transformers above.
Primary voltage insulating systems can be tested with the 5,000VDC range. When
testing primary voltage systems that include lengths of underground cable, the
PT-5000W may initially show a high leakage indication until the cable charges up.
If the high leakage indication does not turn off before the end of the test then leaky
or shorted cable would be indicated. For very long cable lengths, it may be possible
to test only with the 500VDC range.
Содержание PT-5000W
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