7
Safety Techniques
The high voltage circuit of the MegaPulse can be shut off at any time by turning OFF the
rear power switch. Note that there are residual voltages inside the equipment that may take up to
5 minutes to bleed off to safe levels.
The MegaPulse tester is provided with a
VOLTAGE ADJUST
knob on the front panel. This
voltage setting should always confirm by pressing the VOLTAGE ADJUST knob before start
any testing.
The MegaPulse tester is provided with a
CHARGE
switch that is in the unarmed
"Standby" setting when the tester is first turned ON. When the yellow
CHARGE
button is lit,
the tester will not provide high voltage until the
CHARGE
Button and the
TRIGGER
Button
have been pressed in order. To prevent inadvertent operation, the operator should be instructed
not to press the
CHARGE
Button until the test is ready.
The MegaPulse tester has been designed for one-touch operation with the right hand. If
possible, it should be set up to the left and in front of the equipment under test. The equipment
under test should be connected to the MegaPulse tester and then left alone by the operator. After
the operator is clear of the tester and the equipment under test, the operator should turn the rear-
panel power switch to ON, press the
CHARGE
Button, adjust the voltage to the desired level (as
displayed on the front panel meter), then press the
TRIGGER
Button, with his right hand. This
will allow the greatest separation between the operator and the test being conducted.
The MegaPulse tester is designed to bleed the high voltage away after the test has
concluded. In order to ensure that any voltage present in the equipment being tested has been
completely bled away, the operator should not unplug the equipment under test from the
MegaPulse until the front panel meter reads a safe level (40 volts or less is generally considered a
safe level). Pressing the TRIGGER button before disconnecting main power (or turning the
equipment off) will ensure that the internal capacitors are discharged as much as possible.
Using the MegaPulse Impulse Tester
The impulse test involves high voltage and caution should be exercised when using the
tester. Both the
OUTPUT
and
RETURN
leads are floating (not referenced to chassis ground.
The impulse output waveform is Positive on the
OUTPUT
lead relative to the
RETURN
lead
when the output is configured for Normal (
NOR
) polarity. The impulse output waveform is
Negative on the
OUTPUT
lead relative to the
RETURN
lead when the output is configured for
Reverse (
REV
) polarity. 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.
Pressing the POLARITY switch on the front panel can change the polarity of the output
waveform. The polarity is Normal when the
NOR
indicator is lit. In this case, the high voltage
will appear on the
OUTPUT
as a positive pulse relative to the
RETURN
jack. When the
