GENERATOR

Portable Generator Familiarization & Troubleshooting Guide
Section 3 • Generator Diagnostics and Adjustments
XL&MC Generators, 8000-10000
Watt
Refer to Figure 3.4.
Test 1: — Check (AC) Frequency and Voltage
Connect an accurate (AC) frequency meter across the two
parallel blades of one of the panel 120VAC receptacles.
• Start the engine and let it stabilize.
Read the (AC) frequency.A frequency reading of 61-63
Hertz should be obtained.
With the generator engine running:
• Connect the VOM test probes across the parallel blades
of the panel 120VAC receptacles.A reading of
approximately 130-140VAC should be indicated.
If voltage checks as specified:
• Discontinue test.
Test 2: — Check Idle Control Board Input
Using a digital volt meter set to the VDC scale,
• Connect the positive test lead to pin J2 on the idle
control circuit board. Connect the negative test lead to
J3 on the idle control circuit board. Pin J3 is the ground
terminal of the board (Figure 3.5).
If the unit does produce (AC,) but (DC) voltage is not
present at pins J2 and J3, check for a failure in the battery
charge circuit of the generator.
Test 3: — Check Idle Control Switch Operation
Remove wires 83 and 84 from the idle control board. Set a
VOM to measure ohms. Connect the meter test leads to
wires 83 and 84.Turn the idle switch ON.A reading of less
than 0.3 ohms should be measured.Turn the idle switch
OFF.A reading of “Infinity” should be measured.
Test 4: — Check Idle Control Board Outputs
Using a digital volt meter set to the “DC Volts” scale,
• Connect the negative test lead to pin J3 on the idle
control circuit board.
Referring to Figure 3.6, connect the positive test lead as
follows:
Figure 3.6 — Testing Idle Control Board Outputs
Figure 3.5 — Testing Idle Control Board Input
• Start the generator and note the reading.The reading
should measure 12VDC (See note on top of page 62). If
no voltage is present, check to see if the generator is
producing (AC) voltage.
• Individually test the two pins in connector J1 on the
idle control board closest to pin J3.Approximately
12VDC should be measured only while the stepper
motor is moving in either direction.
• Individually test the four pins in connector J1 closest to
pin J4 on the idle control board. Approximately 6VDC
should be measured only while the stepper motor is
moving in either direction.
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