SERVICING
43
S-15A RESISTANCE CHECK (5 TON ONLY)
HIGH VOLTAGE !
D
ISCONNECT
ALL
POWER
BEFORE
SERVICING
OR
INSTALLING
. M
ULTIPLE
POWER
SOURCES
MAY
BE
PRESENT
. F
AILURE
TO
DO
SO
MAY
CAUSE
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
.
WARNING
1. Discharge capacitor and remove wire leads.
D
ISCHARGE
CAPACITOR
THROUGH
A
20
TO
30 OHM
RESISTOR
BEFORE
HANDLING
.
WARNING
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 re-
turns to infinity. (Start capacitor with bleed resistor will not
return to infinity. It will still read the resistance of the resis-
tor).
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 (5 TON ONLY)
Using a hookup as shown below, take the amperage and voltage
readings and use them in the formula:
Capacitance (MFD) = 2650 X Amperage
Voltage
D
ISCHARGE
CAPACITOR
THROUGH
A
20
TO
30 OHM
RESISTOR
BEFORE
HANDLING
.
WARNING
VOLTMETER
CAPACITOR
AMMETER
15 AMP
FUSE
TESTING CAPACITANCE
S-17 CHECKING COMPRESSOR
WARNING
Hermetic compressor electrical terminal venting can
be dangerous. When insulating material which
supports a hermetic compressor or electrical terminal
suddenly disintegrates 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 vapor and liquid contents of the
compressor housing and system.
If the compressor terminal PROTECTIVE COVER and gasket (if re-
quired) are not properly in place and secured, there is a remote
possibility if a terminal vents, that the vaporous and liquid dis-
charge can be ignited, spouting flames several feet, causing po-
tentially 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 im-
pinges on a sufficient heat source.
Ignition of the discharge can also occur at the venting terminal or
inside the compressor, if there is sufficient contaminant 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 ignition
source.
Therefore, proper evacuation of a hermetic system is essential at
the time of manufacture and during servicing.
To reduce the possibility of external ignition, all open flame, elec-
trical power, and other heat sources should be extinguished or
turned off prior to servicing a system.
S-17A Resistance Test
The Inverter on the outdoor control board takes the position sig-
nal from the UVW line, connected with the compressor. If the
system detects a malfunction on the compressor, check the insu-
lation resistance in accordance with the following procedure.
