Compliance West MegaPulse Capacitor A PF Series, Instruction Manual

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4
Using the MegaPulse PF Impulse Tester
The impulse test involves high voltage and caution should be exercised when using the tester. The
RETURN lead is referenced to building ground when properly connected. However, both the OUTPUT
and RETURN leads must always be treated as Hazardous whenever the power switch of the MegaPulse
is in the ON position.
The MegaPulse impulse tester generates the impulse waveform only; it does not determine Passing or
Failing results. It is the operator’s responsibility to monitor the output waveform and determine Passing
or Failing results. In monitoring the impulse waveform, consider the following points: The Impulse
waveform is high voltage and high frequency (short duration). Always ensure that the measuring
instrument (usually an oscilloscope with a high-voltage probe) is rated for the voltage involved, and that
the frequency response of the instrument and probe are capable of measuring the output waveform of the
MegaPulse Impulse Tester. A measuring instrument or probe with a low frequency response will result
in erroneous readings that could be mis-read.
Note that the voltage meter may indicate that some residual voltage is present on the main storage
capacitor, even when the tester is first turned ON. This is due to inherent charging of the internal
capacitors.
Note that the peak amplitude of the measured output waveform is proportional to the voltage that is read
on the front panel of the MegaPulse, but it will always be somewhat lower. This is because the meter on
the MegaPulse is measuring the voltage on the main impulse storage capacitor. This voltage will
intentionally dissipate to some extent before reaching the output leads. Therefore, it is important to
measure the peak amplitude of the output waveform, and adjust the output of the MegaPulse accordingly.