Section IV. OPERATION UNDER UNUSUAL CONDITIONS

TM 5-4120-369-14

Section IV. OPERATION UNDER UNUSUAL CONDITIONS

NOTE

The air conditioner can be equipped for operation in chemical biological radiological

(CBR) environment by connecting filtering equipment to the rectangular covered

opening at the lower left side of the rear surface of the unit.

OPERATION IN EXTREME COLD.

a. General. The air conditioner is designed to operate on the heating cycle in ambient temperatures as low as

minus 50F (-45C) and on cooling cycle with 0F (-18C) air entering the condenser and 70F (21C) air entering the

To start unit in cool mode at 0F (-18C) ambient, have organizational maintenance

personnel jumper LPCO switch (S-5).

b. Before Operating. Before starting on cooling cycle be sure cover is removed from condenser air intake and

discharge. Clear all ice and snow from openings. Be sure all dampers are in operating condition.

After Operation. Install cover over condenser air intake and discharge openings.

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

temperatures make wiring and insulation brittle and easily broken.

OPERATION IN EXTREME HEAT.

NOTE

Unit Preventive Maintenance Checks and Services (PMCS) should be performed at daily intervals.

a. General. The air conditioner is designed to operate in temperatures up to 120F (49C). Extra care should be

taken to minimize the cooling load when operating in extreme high temperatures.

b. Protection.

(1) Check all openings in the enclosure, especially doors and windows, to be sure they are tightly closed.

Limit in and out traffic if possible.

(2) When appropriate, use shades or awnings to shut out direct rays of the sun.

(3) When possible, limit the usc of electric lights and other heat producing equipment.

(4) Limit the amount of hot, outside air introduced through the fresh air damper to that essential for

ventilation.

NOTE

Weatherstripping, the installation of' storm doors, and windows, if appropriate, and insulation of surfaces

exposed to the outside is recommended when operating in extremely high temperatures for extended periods.

c. Cleaning.

(1) Clean outside grilles, coils, filters, and mist eliminator more frequently.

OPERATION IN DUSTY OR SANDY AREA.

NOTE

Unit Preventive Maintenance Checks and Services (PMCS) should be performed at daily intervals.

a. General. Dusty and sandy conditions can seriously reduce the efficiency of the air conditioner by clogging the

air filter, mist eliminator, and coils. This will cause a restriction in the volume of airflow. Accumulation of dust or sand in

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