Additional Information; Adjusting The 120 Ac Voltage; Capacitor Troubleshooting; Capacitor Theory - Carrier ComfortPro PC6000 Operation & Service Manual

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3.9 ADDITIONAL INFORMATION

3.9.1 Adjusting the 120 AC Voltage

This does not need to be adjusted under normal operation. If you find low
AC voltage, check the generator belt, air filter, fuel filters and exhaust
system before adjusting.
1 With the APU running turn all 120-volt components off.
2 Measuring the voltage at the outlet panel adjust the engine speed
until 120 (+/- 10) volts AC and 60 Hz +/- 2 Hz is read.

3.9.2 Capacitor Troubleshooting

1 Disconnect generator output from breaker.
2 With APU running, measure generator output voltage.
3 If voltage < 105 volts AC, try a known good capacitor and retest.
NOTE: Most multimeters will not test this capacitor reliably in either MF
(capacitance) or Ω (resistance) modes. The above methods are the ONLY
reliable means of testing the capacitor without a lab-grade capacitance meter.

3.9.3 Capacitor Theory

A single-phase motor can not be "fed" with just single-phase current
(120 Volt AC), there must be some way to create an artificial second
(or third) phase to smooth out the magnetic filed. Capacitors are electrical
components that help create and strengthen the artificial second phase in
single-phase electric motors. They work much like a battery, storing and
releasing a charge of electricity (AC Voltage) that is out of phase with the
oscillating (AC) current that is fed into the motor.
If single-phase induction motors do not have a second phase (created by
the capacitor) then it will not have an even magnetic field. This will cause
the rotor to hesitate at those spots that are uneven. This hesitation will
cause the rotor to spin slowly or even stop moving (compounding the
problem), draw more current (Amp's), become noisy, and overheat.
The CCU Fan and the Compressor use a Run Capacitor. Run Capacitors
are designed for continuous duty, and are energized the entire time the
motor is running.
The Compressor motor needs a Start Capacitor in addition to the Run
Capacitor. Start Capacitors are designed for momentary use. Start
capacitors stay energized long enough to bring the motor to75% of full
speed (RPM) and are then taken out of the circuit by means of a
Potential Relay.
62-11175 COMFORTPRO SERVICE MANUAL