TM 9-4120-371-14
(9) Carefully slide compressor from air conditioner.
(10) Check the compressor to see if a motor burn out is indicated.
f. Compressor motor burn out
(1) After removal of a bad compressor from the refrigeration system, remove all external tubing and
tip the compressor toward the discharge port to drain sample of oil into a clear glass container.
Avoid inhaling fumes and burns from any acid formed by burn out of oil and refrigerant.
(2)
f the oil is clean and clear, and does not have a burnt acid smell, the compressor did not fail
because of motor burn out. If a burn out is not indicated, proceed to g.
If the oil is black, contains sludge, and has a burnt acid odor, the compressor failed because of
(3)
motor burn out.
(4)
You must clean the entire refrigeration system after a burn out has occurred, since contaminants
will have been carried to many corners and restrictions in the piping and fittings. These contaminants will soon
mix with new refrigerant gas and compressor oil to cause repeated burn outs.
Remove the dehydrator (filter-drier), and blow down each leg of the refrigeration system. To do
(5)
this, connect a cylinder of dry nitrogen to each dehydrator connection, in turn, and open the cylinder shutoff
valve for at least 30 seconds at 50 psig (3.5 kg/cm2) pressure.
(6) Connect the two dehydrator fittings with a jumper, locally manufactured from refrigerant tubing and
fittings.
(7)
Clean system by backflushing with liquid R-11 (item 12, Appendix E) from pressurized cylinder
or circulating pump and reservoir with pressure of at least 100 psig.
If pump is used, connect the discharge line of the refrigerant system to the discharge side of
(8)
pump.
(9)
Connect a line containing a filter to the suction line in the unit.
NOTE
An unused dehydrator or other suitable medium may be used as a filter.
(10)
The other end of the temporary suction line should be connected to a small drum or suitable
reservoir.
(11)
A line should be run from the bottom of the reservoir to the inlet of the pump.
Avoid inhaling fumes and burns from any acid formed by burn out of oil and refrigerant,
Wear a gas mask if area is not thoroughly ventilated. Wear protective goggles or
glasses to protect eyes. Wear rubber gloves to protect hands.
(12) Fill reservoir with fluorocarbon refrigerant, R11, and start the pump. Continue filling the reservoir
with refrigerant, R11, until it begins to pour out of the return line. Continue flushing for at least 15 minutes.
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