7
Test Personnel
Personnel require special training to conduct the dielectric withstand test. They should understand
electrical 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 tests 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.
It is imperative that a good ground be provided to the HT-S unit. Before connecting the HT-S,
ensure that a low-resistance ground is provided by the building wiring. If the HT-S is used on a high-
resistance grounding circuit, dangerous high voltages may be present to the operator. In addition, the
power to the Testing Area should be provided with an easily reached shutoff switch which can be actuated
by personnel outside the area if needed.
Safety Techniques
The high voltage circuit of the HT-S can be shut off at any time by pressing the
RESET
button.
The HT-S has been provided with a Reset button to provide an unarmed "Standby" setting when it is
energized, but idle. When the red
RESET
light is lit the tester will not provide high voltage until the
RESET
button and the
TEST
button have been pressed in order. To prevent inadvertent operation, the
operator should be instructed not to press the
RESET
button until the test is finish.
The HT-S is equipped with a ground continuity check which will not allow high voltage to be
applied if the Test Return Lead is not properly connected. This is an important safety feature and should
not be defeated unless two wire products are being tested. In that event, it is imperative that the operator
make absolutely sure the Test Return Lead is properly connected to the equipment being tested. If the lead
is not properly connected, a dielectric withstand test failure may energize exposed dead metal of the
equipment being tested. Additionally, the HT-S may not recognize the failure. The test will continue for
its normal length of time, and the HT-S may show a "PASS", see connections for more details.
