TM 9-4120-411-14
(a) Remove protective caps from angle drain valve.
NOTE
It may be necessary to slightly pressurize the system using dry nitrogen to remove
oil from the compressor.
(b) Place a suitable container under the angle drain valve then slowly open the valve to remove oil.
(c) Measure and note the amount of refrigerant oil that was removed.
(d) Discard used refrigerant oil in accordance with established guidelines.
(4) When compressor is installed in unit and does not have an oil level indicator or angle drain valve.
(a) Remove low pressure cutout switch located below the reversing val ve per paragraph 5.18.
(c) Remove self-sealing valve core from low pressure cutout switch fitting.
NOTE
It may be necessary to slightly pressurize the system using dry nitrogen to remove
oil from the compressor.
(d) Place a suitable container under the low pressure cutout switch fitting to collect the oil.
(e) Using a suitable lifting device or overhead hoist, lift the unit from the frame cornerpost nearest the
compressor until all oil has been removed.
(f) Measure and note the amount of refrigerant oil that was removed.
(g) Discard used refrigerant oil in accordance with established guidelines.
b. Filling.
(1) Carefully measure the appropriate amount of refrigerant oil as noted during draining and place into a suitable
container. If the amount of oil could not be determined, measure in six pints.
NOTE
Refrigerant oil must be drawn into tie unit using a vacuum pump. This process
can be performed more efficiently if the hose restrictions, such as self-sealing
valve cores and hose depression pins, are removed.
(2) Remove the self-sealing valve cores from the discharge and suction service valves located on the
compressor and reversing valve assembly piping and move the depressions from the ends of any hoses
being used.
(3) Connect one hose to either the suction or discharge service valve and a vacuum pump. Connect a second
hose to the remaining service valve and place into the pre-measured container of refrigerant oil.
(4) Start the vacuum pump and draw the required amount of refrigerant oil into the unit.
When completed,
remove hoses ad install self-sealing valve cores and depression pins as necessary.
Change 1 5-12.1