Compliance West GFM-40ac, Instruction Manual

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6
NOTE
Ensure that the non-detachable
power cord used on the product
to be tested meets the length and
conductor size requirements of
Table 1-1 before attempting to
calibrate the tester. If a non-
detachable power cord not
meeting the length requirements
in Table 1-1 is used, the tester
voltage zero procedure may not
be successful. However, if the
voltage zero procedure is
successful, the GFM-40ac will
test products correctly.
1. The voltage zero procedure requires the use
of a power cord assembly from the EUT.
Remove the power cord assembly from the
EUT or use a representative sample. Crimp
or solder an alligator clip to the green
(grounding) conductor of the cord at the
non-plug end.
2. Connect your GFM-40ac Tester to a
correctly rated source of supply and turn the
power switch to the I or ON position. The
tester will perform a self-diagnostic test. If
the Volts/Amps switch is set to Volts, the
meter will swing.
3. Plug the split end plug of the 10 AWG Test
return lead into the "Chassis" Receptacle of
the Tester.
4. Plug the EUT Power Cord prepared in Step
1 above into the "Device" Receptacle of the
tester. Firmly attach the alligator clip
previously crimped or soldered to the EUT
Power Cord to the alligator clip of the
Return lead. It is imperative that the
connection made is solid, as the accuracy of
the voltage zero adjustment is dependent on
the integrity of this connection.
5. Set the meter selection switch on the front
panel to Volts.
6. Insert the plastic calibration screwdriver into
the potentiometer behind the upper hole in
the rear panel marked "Voltage Zero".
7. Push and hold the Test Button. Holding the
test button will continue the test until the
button is released.
8. With the Test Button pressed, adjust the
"CAL" knob on the front panel.
Simultaneously adjust the rear panel
potentiometer until the meter output remains
steady while the "CAL" knob is adjusted
throughout its range.
9. Confirm proper operation of the v=ir tual
voltage sense circuit by unclipping the
alligator clips from each other and clipping
them to the leads of the rear panel
calibration resistor.
10. With the Volts/Amps switch set to "Amps",
adjust the "CAL" knob on the front panel so
the meter shows a 25A output.
11. Move the Volts/Amps switch to "VOLTS".
Proper operation is confirmed by a 2.5 volt
reading, the voltage drop expected in the
resistor alone.
Operating Techniques
The following paragraphs describe how to
operate your GFM-40ac Tester in both
laboratory use and on the production line. In the
following sections, EUT means Equipment
Under Test.
Testing the EUT (Laboratory Use)
This section describes how the Tester is used to
conduct an actual test.
CAUTION
High current. Risk of burns.
Remove any conductive
jewelry before using the
Tester.
NOTE
If the EUT is equipped with a
detachable power cord, use the
supplied 10 AWG Test Power
Cord , not the EUT power cord.
The accuracy of the calibration
procedure depends on use of the
same power cord type for all
testing.
1. Connect your Tester to a correctly rated
source of supply and turn the power
switch to the I or ON position. The tester
will perform a self-diagnostic test.If the