Compliance West HT-2000PR, Instruction Manual

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8
Chronic Leakage Current Failures
AC Dielectric Withstand testing charges all primary circuit capacitors connected line to ground
or neutral to ground. The current flowing through these capacitors is defined as leakage current.
If almost all examples of a model of equipment are not passing the leakage current test, we
recommend that the leakage current limit be increased by resetting the leakage current level on
the rear panel to a higher level.
If the leakage current adjustment of the HT-PR is set to 20mA AC or 5mA DC and almost all
examples of the model being tested are still failing, the primary circuit capacitance of the
equipment may be too high to allow the AC dielectric withstand test to be used. This is due to
the AC voltage charging all capacitors connected between primary voltage and ground. If the
overall value of these capacitors cause a leakage current of more than 20mA to flow at the
desired test voltage, the HT-PR cannot generate full voltage, and cannot successfully conduct the
dielectric withstand test.
However, a DC dielectric withstand test is acceptable for most categories of equipment and will
not charge the primary circuit capacitors. The DC test can be conducted by switching the front
panel switch to DC (only HT-3000PR). If the problem was due to high leakage current on the
capacitors of the circuit, the test should now be successful.
High Voltage Dielectric Withstand Test
This test checks for insulation system breakdowns between the primary and ground circuits. The
HT-PR uses a separate high-frequency transformer circuit to detect arc breakdowns.
The dielectric withstand test is conducted by shorting the line and neutral conductors of the
power supply cord and applying high voltage between them and the exposed dead metal of the
chassis of the equipment being tested. The duration of the test is controlled by the test time
control on the back panel. The test time is counted from the time the
Full Voltage LED is lit to
the completion of the test.
If the green
Hipot Pass LED light is on, the test cycle has been successfully completed. The
equipment under test is in accordance with the preset test parameters. The HT-PR is ready to test
the next piece of equipment.
High Voltage Dielectric Withstand Test Failures
If the red Hipot Fail LED light is on, a problem has been found with the insulation between
primary and ground. The equipment under test should be examined, reworked and successfully
tested before being shipped.
High Voltage Discharge
The HT-PR is designed to discharge the high voltage after completion of the dielectric withstand
test. The equipment being tested should remain connected to the HT-PR until the voltage has
discharged to a safe level to protect the operator and also to ensure that there is no energy stored
in the tested equipment.