Specifications

185 Rev. 3
SERVICING
S-15B Capacitance Check
Using a hookup as shown below, take the amperage and
voltage readings and use them in the formula:
Capacitance (MFD) = 2650 X Amperage
Voltage
WARNING
DISCHARGE CAPACITOR THROUGH A 20 TO 30 OHM
RESISTOR BEFORE HANDLING.
VOLTMETER
CAPACITOR
AMMETER
15 AMP
FUSE
TESTING CAPACITANCE
S-16 CHECKING FAN AND BLOWER MOTOR
WINDINGS
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, simi-
lar to the compressor internal overload. However, heat gen-
erated within the motor is faster to dissipate than the com-
pressor, allow at least 45 minutes for the overload to reset,
then retest.
WARNING
Disconnect Electrical Power Supply:
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 to not test continuous or a reading is obtained
from lead to ground, replace the motor.
S-17 CHECKING COMPRESSOR WINDINGS
WARNING
HERMETIC COMPRESSOR ELECTRICAL TERMINAL
VENTING CAN BE DANGEROUS. WHEN INSULATING
MATERIAL WHICH SUPPORTS A HERMETIC COMPRES-
SOR ELECTRICAL TERMINAL SUDDENLY DISINTE-
GRATES DUE TO PHYSICAL ABUSE OR AS A RESULT
OF AN ELECTRICAL SHORT BETWEEN THE TERMINAL
AND THE COMPRESSOR HOUSING, THE TERMINAL MAY
BE EXPELLED, VENTING THE VAPOROUS AND LIQUID
CONTENTS OF THE COMPRESSOR HOUSING AND SYS-
TEM.
If the compressor terminal PROTECTIVE COVER and gas-
ket (if required) are not properly in place and secured, there
is a remote possibility if a terminal vents, that the vaporous
and liquid discharge can be ignited, spouting flames several
feet, causing potentially severe or fatal injury to anyone in its
path.
This discharge can be ignited external to the compressor if
the terminal cover is not properly in place and if the discharge
impinges on a sufficient heat source.
Ignition of the discharge can also occur at the venting termi-
nal or inside the compressor, if there is sufficient contami-
nant air present in the system and an electrical arc occurs
as the terminal vents.
Ignition cannot occur at the venting terminal without the pres-
ence of contaminant air, and cannot occur externally from
the venting terminal without the presence of an external igni-
tion source.
Therefore, proper evacuation of a hermetic system is essen-
tial at the time of manufacture and during servicing.
To reduce the possibility of external ignition, all open flame,
electrical power, and other heat sources should be extin-
guished or turned off prior to servicing a system.
If the following test indicates shorted, grounded or open wind-
ings, the compressor must be replaced.
S-17A Resistance Test
Each compressor is equipped with an internal overload.
The line break internal overload senses both motor amper-
age and winding temperature. High motor temperature or
amperage heats the disc causing it to open, breaking the
common circuit within the compressor on single phase units.
The three phase internal overload will open all three legs.
Heat generated within the compressor shell, usually due to
recycling of the motor, high amperage or insufficient gas to
cool the motor, is slow to dissipate. Allow at least three to
four hours for it to cool and reset, then retest.
Fuse, circuit breaker, ground fault protective device, etc. has
not tripped -