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Section 1
An Introduction to Dielectric Withstand Testing with the HT-2800
The continuity test/dielectric withstand test is a production line test which is recognized by safety
agencies worldwide as a valid criterion of safe assembly of end-use equipment. The test ensures that the
primary circuit power and ground conductors were properly wired and connected for safe operation. It also
applies a high-voltage potential between power and ground conductors to make sure that no unintentional
leakage or arcing paths exist between power and ground. The test consists of a continuity check, a leakage
current check and a high voltage check. It is non-destructive to the equipment under test, and can be
accomplished in a short time.
Safety Precautions
The dielectric withstand test generates voltages of up to 2800 volts dc at potentially lethal current
levels. Currents of as little as 5 mA at 120 volts can cause death, and the HT-2800 is capable of generating 5
mA at up to 2800 volts. Because there is no zero volts crossing point as there is for ac voltage, dc voltage is
considered the more dangerous of the two. It is more likely that a person will be thrown clear or be able to
extricate himself from ac because of the zero crossing. The HT-2800 has been designed to minimize exposure
to high voltages. However, the potential for serious injury or death exists and personnel should be aware
when they conduct this test.
Test Personnel
Personnel require special training to conduct the dielectric withstand test. They should
understand ele ctrical fundamentals clearly, and be aware that high voltage is adept and creative at
completing a path to ground. Instructions should include a warning against any metal jewelry. Operators
should not allow others in the testing area, especially when tes ts are being conducted. Organization is to be
stressed. The operator should keep the area free of unused leads and equipment.
Testing Area
The area used for conducting the dielectric withstand test should be as remote as possible from
normal production line activities. Only personnel actually conducting the test should be allowed in the area,
and it should be taped or roped off to preclude casual entry by other employees. In addition, the area
should be marked "WARNING - HIGH VOLTAGE TESTING" or the equivalent to warn others of the nature
of the testing taking place.
The bench being used should be non-conductive, and any exposed metal parts should be tied
together and grounded. If a conductive surface must be used, it should be grounded.
Because of sparking during a dielectric test failure, it is not safe to conduct dielectric withstand
tests in combustible atmospheres.