Table 4-1. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS) QUARTERLY SCHEDULE (cont)

TM 5-4120-393-14

Table 4-1. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS) QUARTERLY SCHEDULE (cont)

Item

Item To Be

No.

Inspected/Serviced

Procedures

Turn TEMPerature control thermostat knob to fully

INCREASE (clockwise) position, then tur n mode

selector switch to COOL. Note that evaporator and

condenser fans start immediately and that compressor

starts approximately 30 seconds later. Hold your hand

in air flow at the center of the conditioned air outlet

grille; there should be no change in temperature. Now

turn TEMPerature control thermostat knob to fully

DECREASE (counterclockwise) position and feel outlet

air temperature begin to drop almost immediately.

Leave controls in present position and perform next

check.

After 15 minutes of operation, check the sight glass

and compare refrigerant condition with the color coded

information plate provided. (See para 2-3.) Ambient

temperature should be above 70F (21 C).

Turn mode selector switch to OFF and observe that all

air conditioner functions cease.

Set-up the air conditioner for the desired operational

mode.

Record performance of quarterly PMCS, including all

corrective actions taken.

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