TM 9-4120-399-14
5-28. COMPRESSOR (B1). - Continued.
f. Compressor Motor Burn Out. - Continued.
(4) You must clean the entire refrigeration system after a burn out has occurred, since
contaminants will have been carried to many comers and restrictions in the piping and fittings.
These contaminants will soon mix with new refrigerant gas and compressor oil to cause repeated
bum outs.
(5) Remove the filter/dryer dehydrator (see para. 5-15), and blow down each leg of the
refrigeration system. To do this, connect a cylinder of dry nitrogen (Appendix E,item 2) to each
filter/dryer connection in turn and open the cylinder shut off valve for at least 30 seconds at 50
psig (3.5 kg/cm) pressure.
(6) Connect the two filter/dryer fittings with a jumper locally manufactured from
refrigerant tubing and fittings.
(7) Clean system by back-flushing with liquid R-11 (Appendix E, item 19) from
pressurized cylinder or circulating pump and reservoir with pressure of at least 100 psig.
(8) If pump is used, connect the discharge line of the refrigerant system to the discharge
side of pump.
(9) Connect a line containing a filter to the suction line in the unit.
NOTE
An unused filter/dryer or other suitable medium may be used as a
filter.
(10) The other end of the temporary suction line should be connected to small drum or
suitable reservoir.
(11) A line should be run from the bottom of the reservoir to the inlet of the pump.
WARNING
Avoid skin contact or inhaling fumes 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 R-11 (Appendix E, item 19) and start the
pump. Continue filling the reservoir with refrigerant R-11 (Appendix E, item 19) until it begins
to pour out of the return line. Continue flushing for at least 15 minutes.
(13) Reverse the pump connections, replace the filter with a new filtering medium, and
backflush the system for an additional 15 minutes.
5-76
