HI-HEAT position, the remaining heaters are en-
ergized, providing maximum heating capacity
( 12,000 BTUH) .
6-3. Repair Procedures
a. If the system must be opened for repair or
replacement of parts, open the suction service
valve and relieve the system pressure. Connect a
hose line to the suction service valve and purge
the refrigerant to an outside area.
b. After purging the system, allow the tubing
to warm to the ambient temperature before open-
ing the system; this delay will help prevent the
formation of condensation on the inside walls of
the tubing. Plug or cap all openings as a part is
removed to minimize the entry of dirt and mois-
c. Use a silver solder on all soldered connec-
tions. Easy-Flo silver solder (or equivalent) with
a 50 percent silver capacity and a melting point
of approximately 1160° F is recommended. Con-
tinually pass dry nitrogen through the tubing or
connections being soldered to prevent formation
of harmful copper oxides.
d. No metal contact on capillary tubes is allow-
able; use tape to prevent such contact.
6-4. Fan Motor
a. On-Equipment Testing. Before removing the
motor for replacement, test the motor windings
for any opens, grounds, and resistance tolerances.
(1) Disconnect electrical connector from
(2) Check for continuity across each combi-
nation of two motor terminals. Lack of continuity
indicates an open winding.
(3) Place one probe of the continuity tester
against the motor housing and the other probe
against each of the motor terminals, one at a
time. If continuity is indicated between any ter-
minal and the housing, the motor is defective.
(4) Connect the motor to a 208V, 3-phase,
60 Hz power source. Use a clampon or inseries
type ammeter and measure the amperage in each
of the motor leads. Amperage should be 4.2 amps
in each lead.
b. Removal. Refer to paragraph 3-36 and re-
move the motor.
c. Disassembly. Refer to figure 6-2 and disas-
semble the motor.
(1) Overload protector. Disconnect the elec-
trical leads from the overload protector (fig.
6-2). Test the protector for continuity; if conti-
nuity does not exist, replace the overload protec-
(2) Motor bench test. Perform the growler
tests on the stator as instructed in TM 5-764. Re-
place a defective stator.
e. Ceaning, Inspection, and Repairs.
(1) Clean all parts with a cloth dampened
in approved cleaning solvent.
(2) Inspect stator
breaks, or other defects.
(3) Inspect bearings
and out-of-round. Replace
housing for cracks,
Replace a damaged or
for pits, scoring, wear,
a damaged or defective
(4) Inspect the rotor shaft for cracks, wear,
or misalinement. Replace a damaged or defective
(5) Inspect the rotor for cracks, breaks, and
damaged laminations. Replace damaged rotor.
(6) Replace stator if it does not meet test
standards (d, above).
(7) Refer to TM 5-764 for motor repair in-
f. Reassembly. Refer to figure 6-2 and reas-
semble the motor.
g. Installation. Refer to paragraph 3-36 and
install the fan motor.
6-5. Refrigerant System Servicing
Warning: Avoid bodily contact with liquid
refrigerant and avoid inhaling refrigerant gas.
Be especially careful that refrigerant does not
come in contact with the eyes. In case of refrig-
erant leaks, ventilate the area immediate y.
a. Testing Refrigerant System for Leaks.
(1) Halide torch leak detector method. The
preferred method of testing for refrigerant sys-
lem leaks is by using a halide torch. The halide
torch exploring tube is passed over all joints, cou-
plings, and valves. A refrigerant leak will cause
the flame of the torch to change from blue to
green. If the leak is large, the flame will be dense
blue with a reddish tip. A very large leak may ex-
tinguish the flame. Mark all spots where leaks
are noticed. Drain the refrigerant system, repair
the leak, and pressure test the system.
(2) Soap solution method. While operating
the air conditioner, brush all possible points of
leakage with soap solution and watch for bub-
bles. Wipe off soap solution and mark leaks.
Drain the refrigerant system; repair leaks and
pressure test the system.
b. Draining. Refer to figure 6-3 and drain the
c. Pressure Testing and Evacuating. Refer to
figure 6-4 and pressure test and evacuate the re-
6 - 3