Service Manual

SERVICING
28
Wiring is subject to change. Always refer to the wiring diagram on the unit for the most up-to-date wiring.
across the start winding will energize the start relay holding
coil and open the contacts to the start capacitor.
Two quick ways to test a capacitor are a resistance and a
capacitance check.
S-15A RESISTANCE CHECK
WARNING
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
Check for Digital Test
1. Set the meter on Ohm range (Set it at lease 1000 Ohm
=1k).
WARNING
Discharge capacitor through a 20 to 30 OHM
resistor before handling.
WARNING
2. Connect the Meter leads to the Capacitor terminals.
3. Digital meter will show a reading momentarily (Figure 1).
Note the reading.
Figure 1 Figure 2
4. Reading will immediately return to the OL = (Open Line)
(Figure 2). Every attempt of Step 2 will show the same
result as was in step 4 and Step 5. This indicates that the
capacitor is good.
5. If there is no Change, then capacitor is dead and must be
replaced.S-15B CAPACITANCE CHECK
S-15B Capacitance Check using a digital multi-
meter (In capacitance mode)
WARNING
Discharge capacitor through a 20 to 30 OHM
resistor before handling.
WARNING
NOTE: You can do this test with a multi-meter if you have a
Capacitance meter on your multi-meter.
1. Remove the capacitor from the circuit.
2. Now Select "Capacitance" on your multi-meter.
3. Now connect the capacitor terminals to the multi-meter
leads.
4. If the reading is near to the actual value of the capacitor
(i.e. the printed value on the capacitor). The capacitor is
good. (Note that the reading may be less than the actual
printed value of the capacitor).
5. If you read a significantly lower capacitance or none at
all, then capacitor is dead and must be replaced.
Capacitance (MFD) =
2650 X Amperage
Voltage
S-16A CHECKING FAN AND BLOWER MOTOR
WINDINGS (PSC MOTORS)
The auto reset fan motor overload is designed to protect the
motor against high temperature and high amperage conditions
by breaking the common circuit within the motor, similar to the
compressor internal overload. However, heat generated within
the motor is faster to dissipate than the compressor, allow at
least 45 minutes for the overload to reset, then retest.
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Remove the motor leads from its respective connection
points and capacitor (if applicable).
2. Check the continuity between each of the motor leads.
3. Touch one probe of the ohmmeter to the motor frame
(ground) and the other probe in turn to each lead.
If the windings do not test continuous or a reading is obtained
from lead to ground, replace the motor.