DIRECT SUPPORT MAINTENANCE
AIR CONDITIONER, HORIZONTAL, COMPACT
OPERATIONAL CHECKOUT AND TROUBLESHOOTING PROCEDURES
Before proceeding with the troubleshooting procedures, check Troubleshooting
Procedures for Unit Maintenance.
COMPRESSOR WILL NOT START.
The compressor will not start.
The LOW and HIGH-pressure switches are tripped.
Check that both the LOW and HIGH PRESSURE switches are not tripped. To
reset, press and release the LOW and HIGH PRESSURE switches. If the switch
The compressor motor thermal cutoff switch is not operational.
Conduct an operational check on the compressor motor thermal cutoff switch. If
the thermal cutoff switch is defective, replace the compressor. (WP 0090 00).
The compressor shows signs of burnout.
Replace the compressor if it shows signs of burn out. (WP 0090 00).
COMPRESSOR SHORT CYCLES
The compressor short cycles.
The head pressure is either too high or too low.
1. Check the head pressure (high pressure side). (WP 0000 00).
a) If the pressure is too high, check the HIGH PRESSURE cutout switch and
replace if defective. (WP 0083 00).
b) If the pressure is excessive and the sight glass is clear, release any excess
refrigerant. Release the pressure until the requirements of (WP 0074 00) are met.
2. Check the head pressure (low pressure side) and add refrigerant if low.