Section IV. TROUBLE SHOOTING
a. This Section contains troubleshooting information for locating and correcting most of the operating troubles
which may develop in the air conditioner. Each malfunction for an individual component, unit or system is followed by a
list of tests or inspections which will help you to determine corrective actions to take. You should perform the
tests/inspections and corrective actions in the order listed.
b. This manual cannot list all malfunctions that may occor, nor all tests or inspections and corrective actions. If a
malfunction is not listed, or is not corrected by listed corrective actions, notify your supervisor.
c. The Table lists the common malfunctions which you may find during the operation or maintenance of the air
conditioner or its components. You should perform the testinspections and corrective actions in the order listed.
Before you use this Table, be sure you have performed all applicable operating checks.
Table 4-2. Troubleshooting
TEST OR INSPECTION
1. AIR CONDITIONER FAILS TO OPERATE
Check to be sure that main power cable is connected.
Check mode selector switch for correct setting.
Turn selector switch to COOL.
Verify that circuit breaker has not tripped.
Pull then push the circuit breaker resset knob.
Make sure that you are using 208-volt, 50/60 cycle, 3-phase current.
Check each phase of supply line with voltmeter.
Inspect main power receptacle connector for breakage.
Replace broken connector.
Cheek for loose electrical connections.
Verify that high- and low-pressure cutout switches have not opened.
Press and release reset buttons on high- and low-pressure cutout switches.
Disconnect power from the air conditioner before doing maintenance work on the electrical
system. The voltage used can be lethal.
Replace bad fuses.
Check transformer: 208-volt primary, 30-volt secondary.
Check rectifier assembly by applying 30 + 3-volt ac to input terminals, and observing voltmeter attached to (+)
and (-) terminals. Voltmeter should read 2428 volts, dc.
Replace bad rectifier assembly.
2. INSUFFICIENT COOLING
Check evaporator intake and outlet louvers to be sure they are open and not obstructed.
Open louvers or remove obstruction.
Make sure that mode selector switch is positioned properly.
Set switch at COOL.
Verify that temperature selector switch is properly set.
Set switch at maximum DECREASE.