Compliance West MegaPulse 2x10s-2.5, Instruction Manual

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16
TestMinder Operation
TestMinder computer operation is described in a
specific manual included with your tester, if so
equipped.
Please be sure to start TestMinder before the
MegaPulse. For safety considerations, the
MegaPulse output should be set to zero when
energized.
EN60335 Pulse Trains
The MegaPulse Tester is a manual device.
When the MegaPulse 1.2x50-7 is equipped with
the 60335 Option, Including Fast Charge Supply
and Virtual 12 ohm Impedance Output, Pulse
trains of alternating polarity can be
approximated by using the CHARGE,
POLARITY and TRIGGER buttons on the front
panel of the tester.
1.
To begin the pulse train, push the
CHARGE button. The MegaPulse will
charge to the preset level within 2 sec.
2. Push the TRIGGER button, releasing
the surge to the EUT. Immediately push
the POLARITY button, which will switch
the pulse polarity, in accordance with
EN60335.
3. Push the CHARGE button.
4. Push the TRIGGER button. Time the
sequence so the TRIGGER button is
pushed every 2 seconds.
NOTE: If the MegaPulse is equipped with
TestMinder, the pulse train information
can be entered and the pulse trains will be
under computer control. See the
TestMinder Manual for details.
Breakdown Detection Circuit
Option
The MegaPulse tester can optionally be
configured with a Breakdown Detection circuitry
that can detect a quickly decaying waveform,
indicative of a breakdown in the insulation
system being tested. This circuit detects
abnormal current flows and interprets this flow
as a failure of the insulation system being tested.
Proper operation requires calibration of the
Sensitivity Control when the output voltage is
changed. For best results, a known good and a
known bad sample of the insulation system can
be used to set the Sensitivity Control. If these
samples are not available, a starting setpoint can
be set with the supplied calibration resistor (50
ohms).
Sensitivity setting using known
good and known bad samples
1. Remove power to the MegaPulse and turn
the Voltage Control to zero. Turn the
Sensitivity Control to the maximum setting,
i.e. the knob pointer at 5 o’clock.
2. Using the supplied High Voltage Test leads,
connect the known bad sample across the
High Voltage outputs of the MegaPulse.
3. Energize the MegaPulse and press the
Charge Button. Use the Voltage Control to
set the output to the desired level as shown
on the MegaPulse voltage meter.
4. Press the TRIGGER button. The green
PASS light should illuminate.
5. Retest, turning the Sensitivity Control to a
progressively lower setting, until the red
FAIL light lights. In general, the pointer on
the knob will be at approximately 2 o,clock
for 10-12kV and approximately 8 o’clock
for 1-2kV test voltages.
6. Check the setting by substituting the known
good sample in the circuit, and ensuring the
result is a green PASS light. If it is not, the
difference in resistance between the known
good and known bad samples appears the
same to the Breakdown Detection Circuit. It
may help to repeat the setup using the
known bad sample, and working to define
the point of failure exactly by repeating tests
until the exact point where the red FAIL
light illuminates.
7. If the output voltage of the MegaPulse is
changed, the Sensitivity Control should be
reset.
Approximate Sensitivity Setting
using the supplied 50 ohm resistor
If known good and known bad samples are not
available, an approximate setting, using a 50
ohm resistor, is a recommended starting point.
Depending on requirements of the particular test
being conducted, a higher or lower resistance
may be indicated. We have chosen the 50 ohm
resistor as a balance between repeatability and
sensitivity. As the resistance of the test resistor
increases, current flow decreases, and this may