SERVICING
29
relay holding coil is wired parallel with the start winding. As
the motor starts and comes up to speed, the increase in
voltage 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.
START
RELAY
C
O
M
H
E
R
M
F
A
N
RUN
CAPACITOR
CONTACTOR
T2 T1
L1
L2
START
CAPACITOR
RED 10
VIOLET 20
YELLOW 12
ORANGE 5
HARD START KIT WIRING
S-15A RESISTANCE CHECK
1. Discharge capacitor and remove wire leads.
WARNING
Discharge capacitor through a 20 to 30 OHM
resistor before handling.
OHMMETER
CAPACITOR
TESTING CAPACITOR RESISTANCE
2. Set an ohmmeter on its highest ohm scale and connect
the leads to the capacitor -
A. Good Condition - indicator swings to zero and slowly
returns to infinity. (Start capacitor with bleed resistor will
not return to infinity. It will still read the resistance of the
resistor).
B. Shorted - indicator swings to zero and stops there -
replace.
C. Open - no reading - replace. (Start capacitor would
read resistor resistance.)
S-15B CAPACITANCE CHECK
Using a hookup as shown below, take the amperage and
voltage readings and use them in the formula:
VOLTMETER
CAPACITOR
AMMETER
15 AMP
FUSE
TESTING CAPACITANCE
WARNING
Discharge capacitor through a 20 to 30 OHM
resistor before handling.
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 condi-
tions 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.
