TM9-4120-398-14
b. A schedule for unit preventive maintenance inspection and service should be established immediately after
installation of the air conditioner. A quarterly interval, equal to three calendar months or 250 hours of operation (whichever
occurs first) is recommended for usual operating conditions. When operating under unusual conditions, such as a very dusty or
sandy environment it may be necessary to reduce the interval to monthly or even less if conditions are extreme.
c. Table 4-1 lists the unit preventive maintenance checks and services that should be performed at quarterly intervals (or
otherwise stated in table 4-1). The PMCS items in the table have been arranged and numbered in a logical sequence to provide
for greater personnel efticiency and least amount of required maintenance downtime.
WARNING
HIGH VOLTAGE
is used in the 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. For artificial respiration, refer
to FM 2111. 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 208/230 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, louvers, and covers in place and tightly secured.
4-7