TM9-4120-400-14
SYMPTOM INDEX
Malfunction No.
Trouble
AIR CONDITIONER
Insufficient Cooling . . . . . . .. . . . . . . . . . . . . . . . . . . . . ..
Noisy During Operation . . .. . .. . . .. . .. . ... . . . .. . . . . . . . . . . ..
Operates Continuously On Cooling Cycle . . . .. . . . . . . . . . ..
COMPRESSOR
Will Not Start. . . . . . . . . . . . . . . .. . . . . . . . . .. . . . . . . .1
Short Cycles. . . . . . . . . . . . . . . . . .. . . . . . . . . .2
Refrigerant System
Contaminated. . . . . . . . . . . . . . . . . . .. . . .. . . . . . . . . . . . . . . . . 6
TROUBLESHOOTING
MALFUNCTION
TEST OR INSPECTION
C O R R E C T I V E ACTION
COMPRESSOR WILL NOT START.
NOTE
Be sure and check ltem 5, Steps 1 through 10, Table 4-2 Troubleshooting for unit
maintenance before proceeding with Step 1.
Step 1. Check that the LOW and HIGH PRESSURE cutoff switches are not tripped.
Press and release the LOW and HIGH PRESSURE switches to RESET. If switches do not
remain in, check and/or replace switches. (See para 5-28 and 5-29.)
Step 2. Check that the compressor motor thermal cutoff switch is operational. (See para 5-35.)
Replace compressor if thermal cutoff switch is defective.
Step 3. Inspect and check compressor for burnout. (See para 5-35.)
Replace burned out compressor.
COMPRESSOR SHORT CYCLES.
Step 1. Check head pressure (high pressure side) (See para 5-19.)
a. If pressure is too high, check HIGH PRESSURE cutout switch and replace if defective.
(See para 5-28.)
b. If pressure is excessive and sight glass is clear, release excess refrigerant.
(See para 5-11.) Release pressure until requirements of paragraph 5-19 are met.
5-3
