OPERATION IN EXTREME COLD

TM 9-4120-425-14&P

OPERATION UNDER UNUSUAL CONDITIONS - Continued

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OPERATION IN EXTREME COLD

General

The air conditioner is designed to operate on the heating cycle in ambient temperatures as low as -50F (-45C) and on

cooling cycle with 35F (1.6C) air entering the condenser and 70F (21C) air entering the evaporator.

Before Operation

Before starting operation be sure canvas cover is rolled up and secured. Clear all ice and snow from openings. Be sure all

dampers are in operating condition.

After Operation

Roll down and snap on canvas cover over condenser intake and outlet.

CAUTION

Do not disturb wiring during cold weather unless absolutely necessary. Cold

temperatures make wiring and insulation brittle and easily broken.

OPERATION IN EXTREME HEAT

General

The air conditioner is designed to operate satisfactorily at temperatures up to 120F (49C). If unit is operated at

condenser inlet temperatures higher than 120F (49C), the cooling capacity will be lowered and long periods of

operation at extended temperatures may cause compressor or condenser fan motor to overheat and trip their internal

overload switches or the high pressure cutout switch to shut the unit off.

Filters

To maintain the highest capacity of the unit, the evaporator intake filter and fresh air screen should be cleaned weekly or

more often if necessary. Dirty filters reduce the flow of air across the evaporator coil, thereby reducing the capacity of

the air conditioner.

Guards and Louvers

Keep all guards and louvers clean and free of any obstructions to maintain full air flow through the air conditioner.

Ensure the condenser louver in the rear of the unit is open.

Coils

Clean evaporator and condenser coils as frequently as necessary to prevent dirt or other matter from obstructing the air

flow.

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