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STEP 3.
STEP 4.
STEP 5.
STEP 6.
SET THE REFRIGERANT DRUM IN AN INVERTED POSITION ON A SCALE,
DO NOT OPERATE THE AIR CONDITIONER. OPEN CHARGING LINE VALVE
AND CHARGING VALVE AND CHARGE REFRIGERANT SYSTEM UNTIL
SYSTEM AND DRUM PRESSURES HAVE EQUALIZED OR UNTIL 3.5 POUNDS
OF REFRIGERANT HAVE ENTERED THE SYSTEM.
CLOSE VALVES AND CAREFULLY LOOSEN THE CHARGING LINE TO RELEASE
TRAPPED PRESSURE. DISCONNECT CHARGING LINE AND INSTALL CHARGING
VALVE CAP. OPERATE AIR CONDITIONER IN COOLING MODE FOR 15 MINUTES.
CHECK LIQUID SIGHT INDICATOR. IF SYSTEM IS SHORT OF REFRIGERANT,
GAS BUBBLES WILL APPEAR REGULARLY IN THE INDICATOR. IF REFRIGERANT
SYSTEM IS UNDERCHARGED, ADD ADDITIONAL REFRIGERANT FOLLOWING
STEPS 6 THROUGH 9.
USING SAME DRUM AND CHARGING LINE, PLACE DRUM IN AN UPRIGHT
POSITION ON A SCALE. REMOVE CAP FROM LOW PRESSURE (SUCTION SIDE)
CHARGING VALVE AND LOOSELY CONNECT CHARGING LINE TO VALVE.
PURGE AIR FROM LINE AS IN STEP 2.
CAUTION:
WHEN ADDING REFRIGERANT, USE EXTREME CARE TO AVOID ADDING
STEP 7.
STEP 8.
STEP 9.
6-4. Repairing
REFRIGERANT TO THE SYSTEM TOO FAST WHICH WOULD CAUSE SLUGGING
AT THE COMPRESSOR.
WITH THE AIR CONDITIONER OPERATING, ADMIT GAS TO SYSTEM SLOWLY
(APPROXIMATELY 1 OUNCE PER MINUTE). CONSTANTLY OBSERVE DRUM
WEIGHT TO INSURE THAT ONLY 3.5 POUNDS TOTAL WEIGHT OF REFRIGERANT
IS IN SYSTEM.
REPEAT STEP 4.
CHECK LIQUID SIGHT INDICATOR. IF INDICATOR REGULARLY SHOWS BUBBLES,
REPEAT STEPS 6 THROUGH 9 ADDING REFRIGERANT IN 4 OUNCE INCREMENTS
UNTIL INDICATOR IS CLEAR.
ME4120-239-14/6-2 (2)
Figure 6-2. Charging refrigerrnnf system (Sheet 2 Of 2).
Refrigerant Leaks
a. Locate leak (para 4-64).
b. Discharge system (para 6-3), repair leak, and
recharge system (para 6-3).
Note. If soldering is necessary on any part of the system,
a constant purge of dry nitrogen must be fed through the
system being soldered to prevent scale formation within the
system.
6-5. Decontamination
a. General. The compressor is a hermetically
sealed unit and cannot be repaired. An inoperative
compressor is usually due to a mechanical failure or
motor burnout. If the compressor is mechanically
frozen or sustains a motor burn out it must be
replaced. A compressor failure generates h i gh
temperature causing
a breakdown of oil and
refrigerant with the resulting formation of acid,
moisture, sludge. These products are extremely
corrosive and ‘must be flushed from the system or
repeated burn outs will occur.
b. Procedure.
(1) Discharge system and purge with nitrogen
(para 6-3).
(2) Remove defective motor compressor (para
5-17).
(3) With compressor out of system, purge all
lines with dry nitrogen.
(4) Install a new compressor (para 5-17)
containing a full and proper oil charge.
(5) Replace the dehydrator (para 5-24). This
drhydrator will later be replaced.
6-5
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