TM 9-4120-403-14
Section IV UNIT TROUBLESHOOTING
4-9.
GENERAL
a. This section contains troubleshooting information for locating and correcting most of the operating troubles
which may develop in the air conditioner unit. 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 occur, 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. Table 4-2 lists the common malfunctions which you may find during the operation or maintenance of the air
conditioner unit or its components. Before using this table, be sure you have performed all applicable checks and the
tests/inspections and the corrective actions in the order listed.
WARNING
HIGH VOLTAGE
is used in operation of this equipment.
DEATH ON CONTACT
may result if personnel fail to observe safety precautions.
Never work on electrical equipment unless there is another person nearby who is familiar with operation
and hazards of equipment and who is competent in administering first aid. When technician is aided by
operators, he must warn them about dangerous areas.
Whenever possible, input power supply to equipment must be shut off before beginning work. Take
particular care to ground every capacitor likely to hold a dangerous charge. When working inside, after
power has been turned off, always ground every part before touching it.
Be careful not to contact high-voltage connections of 115 volts ac input when installing or operating this
equipment.
Whenever nature of operation permits, keep one hand away from equipment to reduce hazard of current
flowing through vital organs of the body.
Do not operate equipment without all grilles, guards, louvers, and covers in place and tightly secured.
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