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Fuses - TM-5-4120-337-140046
TM-5-4120-337-14 Air Conditioner Vertical: Compact Self-Contained Air Cooled Electrical Motor Driven Manual
Heater Thermostat
and using an ohmmeter measure for continuity
in the LOW speed position. Using an ohmmeter a
a c r o s s terminals 2 and 3 of terminal board TB2 in
high resistance should be read between contacts 1
the junction box. If the temperature at the ther-
a n d 2. Place the switch in the High speed position.
mostat (located on the rear panel above the con-
Zero ohms should be read between contacts 1 and
d e n s e r coil) is above 50 F., the resistance should
be very low. An open circuit (high resistance)
c. Removal. Remove the hexagon nut which
indicates that the thermostat is defective.
s e c u r e s the switch to the front of the control panel.
c. R e m o v a l . R e m o v e t h e t w o s c r e w s w h i c h
d. Installation. Installation shall be in the
reverse order of removal.
s e c u r e the thermostat and gasket to the rear panel.
Remove the junction box from the air conditioner
Fan  Motor
(para 4 - 3 6 b ) . Remove electrical plug P4 from the
l e f t back of the junction box. Disconnect electrical
a. Function. Two capacitors are incorporated in
connector P4 per paragraph 4-49. Unsolder only
the electrical circuit to improve the power factor,
the two wires V8D16 and V9A16 which are an
reduce motor currents, supply the required starting
integral part of the outside air thermostat.
torque for the fan and compressor motors and to
d. Installation. Installation shall be in the
i m p r o v e the efficiency of the two motors. One run
reverse order of removal.
c a p a c i t o r C2 is utilized to improve the compressor
4-49. Wiring Harness Repair
motor characteristics and the second capacitor C1
i s utilized to improve the fan motor characteristics.
a . General. Six wiring harnesses are used in the
air conditioner to distribute the control and elec-
b. Removal. Remove the junction box from the
trical power supply.  If a harness is severely
air conditioner (para 4 - 3 6 d ) . Tag and disconnect
t h e four leads to the two capacitors located behind
damaged, it should be replaced. The procedures
the left side junction  box mounting bracket.
c o n t a i n e d here provide for repair to minor damage.
Remove the four screws located on the lower left
b. Test and Inspection.
o u t s i d e panel of the air conditioner casing. Lift the
(1) Inspect the connectors for cracked or
capacitor and bracket assembly out of the air
damaged shells and for bent pins.
c o n d i t i o n e r . Remove the two nuts and screws which
(2) Inspect the harness wiring for broken
s e c u r e the capacitor retaining strap to the mounting
wires and frayed or damaged insulation.
bracket and remove the capacitors.
(3) Use an ohmmeter and check continuity of
c. Testing. A c a p a c i t o r  s u s p e c t e d o f b e i n g
each wire from the pin of one connector to the
d e f e c t i v e should be inspected for cracks or external
corresponding pin of the other connector, (wiring
diagram fig. 1-5). Ohmmeter should read ap-
deformation. If a visual defect is observed the
proximately zero ohms.
c a p a c i t o r may be assumed to be defective. Shorted
fuses or a tripped circuit breaker is an indication
( 4 ) Check continuity between each pin and all
other pins on all connectors. Infinite ohms should
t h a t a capacitor is shorted. A shorted run capacitor
exist between all pins, unless connected as shown
will also run hot. If the compressor or fan motor
on wiring diagram.
starts and runs but fails to carry the load or trips
c. Disassembly.
out the protector when not overloaded, an open
running capacitor is indicated. Take an amp
(1) Disassemble the connector to gain access
to the wiring soldered to the connector pins.
reading of the motor associated with a suspect
(2) To remove a wire, unsolder it from the
c a p a c i t o r with the capacitor both in and out of the
p i n s on each connector and pull the wire from the
circuit. If the current draw of the motor does not
harness assembly.
i n c r e a s e with the run capacitor out of the circuit, it
indicates an open capacitor. The capitance rating
( 3 ) To remove a connector, unsolder all wires.
one at a time, from the connector to be removed.
may be checked using the procedures specified in
Tag each wire as it is unsoldered.
paragraph 4-43b. Test voltage shall not exceed
d. Reassembly. Reassemble the connector shells
370 volts for this test.
i n reverse order of removal. Be sure that the shell
d.  installation. Installation shall be in the
reverse order of removal.
insulator is in place and not damaged.
4-48. Outside Air Thermostat
4-50. Heating Elements
a. Function. The outside air thermostat is a
a. Function. There are two banks of three
normally open device which opens at 50 F. to
heating elements per bank. Their purpose is to
prevent operation of the compressor below this
p r o v i d e heated air on demand. They are controlled
by a relay and a selector switch. When the mode
b . Testing. R e m o v e t h e f r o n t a c c e s s p a n e l ( p a r a
s e l e c t o r switch is placed in LO-HEAT position, one
4-12) and the junction box cover (para 4 - 3 6 b ) .
bank of three heating elements is energized; with
P l a c e the mode selector switch in the OFF position
the selector switch in HI-HEAT position, both

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