Section IV. OPERATION UNDER UNUSUAL CONDITIONS

TM 5-4120-352-14

Section IV. OPERATION UNDER UNUSUAL CONDITIONS

2 - 1 0 . Operation in Extreme Cold

filters, coils, electrical components and grilles. Use

compressed air, if available, to aid in cleaning.

a. General. The air conditioner is designed to

c. Air Filters and Coils.

operate on the heating cycle in ambient tem-

(1) Under extremely dusty or sandy condi-

peratures as low as minus 50F (-45C) and on cool-

tions, the louvers, filters, coils, electrical com-

ing cycle with 0F (-18C) air entering the con-

ponents and grilles must be serviced more often.

denser and 70F (21C) air entering the evaporator.

b. Before Operation. Before starting on cooling

NOTE

cycle be sure cover is removed from condenser air

Never operate the unit without having the air fil-

intake and discharge. Clear all ice and snow from

ters in place.

openings. Be sure all dampers are in operating con-

(2) The condenser coil is subjected to ambient

dition.

air. Therefore, it requires cleaning more often than

c. After Operation. Install cover over con-

the evaporator coil.

denser air intake and discharge openings.

2-13.

Operation Under Rainy or

CAUTION

Do not disturb wiring during cold

H u m i d Conditions

weather unless absolutely necessary.

Take special precautions to keep equipment dry.

Cold temperatures make wiring and

If installed outdoors, cover the equipment with a

insulation brittle and easily broken.

waterproof cover when it is not in use. Remove

cover during dry periods. Take all necessary pre-

O p e r a t i o n in Extreme Heat

2-11.

cautions to keep the electrical components free

a. General. The air conditioner is designed to

from moisture.

operate satisfactorily at temperatures up to plus

120F (49C). If unit is operated at condenser inlet

temperatures higher than 120F (49C), the cooling

capacity will be lowered, and long periods of oper-

Make sure power is disconnected

ation at extended temperatures may cause con-

from air conditioner before touching

denser or condenser fan motor to overheat and trip

any wiring or other electrical parts.

their internal overload switches or the high pres-

sure cutout switch will shut the unit off.

2 - 1 4 . Operation in Salt Water Areas

b. Filters. To maintain the highest capacity of

the unit, the return air filter and fresh air screen

a. General. Wash the exterior and condenser

should be cleaned weekly or more often if necessary.

section of the unit, particularly condenser air dis-

Dirty filters reduce the flow of air across the evapo-

charge louver control mechanism, with clean fresh

rator coil, thereby reducing the capacity of the air

water at frequent intervals. Be careful not to dam-

conditioner.

age electrical system with water. Special attention

c. Guards and Louvers. Keep all guards and

must be given to prevent rust and corrosion.

louvers clean and free of any obstructions to main-

tain full air flow through the air conditioner.

d. Coils. Clean evaporator and condenser coils

Disconnect power source prior to

as frequently as necessary to prevent dirt or other

washing the air conditioner.

matter from obstructing the air flow.

2-12. Operation in Dusty or Sandy

b. Painting. Paint all exposed areas where

Areas

paint has cracked, peeled, or blistered, or report con-

dition to organizational maintenance. Coat all ex-

a. Protection. Shield the air conditioner from

posed areas of polished metal with a light coat of

dust as much as possible. Take advantage of any

grease.

natural barriers which offer protection.

b. Cleaning. Keep the air conditioner as clean

as possible. Pay particular attention to the louvers,

2-15