SAFETY PRECAUTIONS
Troubleshooting
Working on air-conditioners can be very dangerous
The following chart (table 11-5) details some of the
if safety precautions are not taken. The following safety
more common problems encountered in trouble-
precautions are mandatory to prevent injury to
shooting an A/M32C-17 mobile air-conditioner. Also
personnel working on or in the immediate vicinity of
listed are suggested ways to fix the problems. Some of
air-conditioning units.
the steps may seem complicated, but they are really
basic troubleshooting procedures with which you need
Use approved goggles or a face shield when
to become familiar. As always, for more detailed
handling refrigerants.
information, refer to the technical manual NAVAIR
Do not allow liquid refrigerant to contact the
19-60-87.
skin.
Table 11-5.--Troubleshooting the A/M32C-17
INDICATION
PROBABLE CAUSE
SUGGESTED REMEDY
A. Compressor fails to start
1. Electromagnetic clutch not 1. Replace or repair
operating
electromagnetic clutch.
2. Broken or sheared coupling
2. Replace coupling.
3. Seized compressor, locked 3.
Overhaul compressor.
or damaged mechanism
4.
Check for loss of refrigerant.
4. Suction pressure below
Repair leaks and recharge.
setting of low-pressure
5.
Refer to G below.
5. Discharge pressure above
6.
Check compressor oil level,
cut-in setting of
oil pressure, wiring and
high-pressure cutout switch
controls.
6. Oil failure switch cutout
B. Compressor
1. Low-pressure controller
1. Reset low-pressure cutout, or
"Short-Cycles"
differential set too close
replace.
2. High-pressure controller
2. Reset high-pressure cutout or
differential set too close
replace.
3. Reduced airflow. Iced
3. Clean or defrost evaporator
coils. Check filters and fan
drive.
a. Dirty air filter
4. Repair or replace valve.
b. Broken fan belt
5. Remove excess refrigerant or
c. Improper fan belt
purge noncondensible gas and
tension
check for leaks.
4. Leaking liquid line solenoid
6. Repair refrigerant leak and
valve.
recharge.
5. Overcharge of refrigerant or
7. Clean or replace strainer
noncondensible gas in
system
6. Insufficient refrigerant
7. Restricted drier strainer
11-33
