TM 55-203
piece bolts.
Both should be tied tightly in place.
oil, or after any change resulting in the loss of oil Add
Enclosing covers of tin should be placed over the
more oil if required.
condenser openings on both ends of the unit and the
(5) Check that all shutoff valves are in open
condenser fan opening in the back cover of the unit.
position before starting equipment. This is particularly
(9) Shut off the air pressure to the spray water
applicable to the compressor discharge shutoff valve, as
supply tank where a separate tank is provided, and drain
the compressor will be damaged if it is operated with
the system. If separate water tanks are not provided,
these valves closed.
close the valve in the water line leaving the tank.
(6) Service valves to be left open will be
(10) Clean the strainers in the water line of
turned back slightly from the wide open position to insure
sediment and dirt.
that they will not bind in the open, or back seated position.
(11) Open the petcocks in the spray nozzle
(7) Purge all parts previously opened to the
piping to drain all the water out, then close petcocks and
atmosphere to remove all air by releasing some
blow down openings to prevent the entrance of dirt and
refrigerant.
foreign matter during the winter period.
(8) Check thoroughly for leaks at any point
where repairs have been made.
i. Summer Preparation. Before operation of the
(9) Seal all valve connection plugs by
applying Clyptol to the slug threads. Do not apply it to the
air-conditioning equipment after the winter shutdown
female threads.
period, take the following actions:
(10) Use new gaskets when replacing parts
(1) Remove all winter hoods and covers.
requiring gaskets. Be sure all parts are removed from the
(2) Inspect the apparatus for cleanliness and
surfaces before new gaskets are applied.
blow out any dirt that may have collected.
(3) Examine all bearings; add any lubrication
h. Winter Preparation. When the use of air
required.
(4) Tighten all bolted joints in the wiring.
conditioning equipment is discontinued for the winter
(5) Inspect all contacts in the control for
months, the following precautions should be taken:
proper condition.
(1) Close the receiver shutoff valve and pump
(6) Check brushes in the motor for freedom
the refrigerant into the receiver, stopping the operation as
and spring pressure.
soon as 5 pounds suction pressure is reached.
(7) Remove the slushing compounding from
(2) Leave the crankcase with this positive
the compressor flywheel and motor pulley and replace the
pressure imposed to help prevent air and moisture from
belts, keeping each set of belts intact. Check belt tension
being drawn into the system at the shaft seal.
and the proper alinement of pulleys.
(3) Close the condenser shutoff valve, the
(8) Loosen or remove both purge plugs, and
compressor suction cutoff valve, and the compressor
note whether or not any Freon is purged from the
discharge shutoff valve. Leave all other valves in normal
compressor.
operating position.
(9) Operate the compressor by hand to pull a
(4) Remove the compressor driving belts,
vacuum on the crankcase; then open the receiver shutoff
keeping each set intact and store them in a clean dry
valve and the compressor suction shutoff valve. This will
place.
permit Freon to flow from the receiver to the compressor
(5) Cover the unpainted surfaces of the
crankcase. Again rotate the compressor by hand to purge
compressor flywheel pulley and motor pulley with rust
any air that has leaked into the crankcase.
preventive.
(10) Replace the purge plugs and open the
(6) Remove the d.c. compressor motor fuse.
compressor discharge cutoff valves and condenser
(7) Place the narrow canvas belt provided
shutoff valves. Check all valves for operating positioning,
with the equipment over the fan openings in the middle of
and replace the d.c. compressor motor fuse.
the motor. The ends of the belt should be at the bottom
(11) Operate the equipment for a few minutes
and the belt tied tightly around the motor.
and check oil level in the compressor crankcase. Operate
(8) Place the canvas hood over the pulley and
for an hour making checks at intervals on refrigerant and
the commutator end of the motor. The drawstring at the
oil levels.
end of the hood will be at the outer end of the motor
(12) Check all joints for Freon leaks.
frame, while the drawstring placed through the ears of
extensions of the hood will be behind the rear row of pole
12-4
Previous Page
