Operation in Extreme Heat. - TM-5-4120-355-140025

TM 5-4120-355-14

b. Electrical System. Make sure the electrical system is free of ice and moisture.

CAUTION: Do not disturb the wiring during cold weather unless absolutely necessary. Cold temperatures make wiring

and insulation brittle and are easily broken.

27. 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 cooperate in temperatures up to 120F (49 C). 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 use 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.

28. Operation in Dusty or Sandy Areas.

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 the condenser

coil and/or in the compressor compartment may cause overheating of the refrigeration system. Dust or sand may also clog the

condensate trap and water drain lines.

CAUTION: Never operate the air conditioner without having the air filters in place.

b. Protection.

(1) Shield the air conditioner from dust as much as possible.

(2) Take advantage of any natural barriers which offer protection.

(3) Limit the amount of dusty or sandy outside air introduced through the fresh air damper.

(4) Roll down and secure the fabric cover on the back of the cabinet during periods of shutdown.

c. Cleaning.

(1) Keep the air conditioner as clean as possible.

(2) Pay particular attention to the outside grilles, condenser, filters, mist eliminator, louvers, and electrical

components.

(3) in extreme conditions, daily cleaning of condenser, filters, and outside grilles may be necessary.

29. Operation in Salt Water Areas.

Wash the exterior of the unit with clean, fresh water at frequent intervals. Do not damage the electrical equipment during

the cleaning operation. Coat exposed metal surfaces with rust proofing material. Remove corrosion and paint the exposed metal

surfaces.

2-10. Operation at High Altitudes.

The air conditioner is designed to operate without special attention at altitudes up to 5,000 feet.

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