Section V. OPERATION UNDER UNUSUAL CONDITIONS
2-12. Operation in Extreme Cold
Caution: To start unit on cool mode at O°F
ambient ( min. operating temp), jumper LPCO
a. General. The air conditioner is designed to
the heating cycle in ambient t e m -
peratures as low as minus 50° F (Fahrenheit) and
on cooling cycle with O°F air entering the con-
denser and 70° F air entering the evaporator.
b. Before Operation. 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
c. After Operation. Install cover over condenser
air intake and discharge openings.
Caution: Do not disturb wiring during cold
weather unless absolutely n e c e s s a r y .
brittle and easily broken.
2-13. Operation in Extreme Heat
a. General The air conditioner is designed to
operate satisfactorily at temperatures up to plus
120°F. If unit is operated at condenser inlet
120°F, the cooling
capacity will be lowered and long periods of
at extended temperatures may cause
condenser or condenser fan motor to overheat and
trip their internal overload switches or the high
pressure cut out switch will shut the unit off.
b. Filters. To maintain the highest capacity of the
unit, the return air 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
c. Guards and Louvers. Keep all guards and
louvers clean and free of any obstructions to
maintain full air flow through the air conditioner.
d. Coils. Clean evaporator and condenser coils as
frequently as necessary to prevent dirt or other
matter from obstructing the air flow.
2-14. Operation in Dusty or Sandy Areas
a. Protection. Shield the air conditioner from
dust as much as possible. Take advantage of any
natural barriers which offer protection.
b. Cleaning. Keep the air conditioner as clean as
possible. Pay particular attention to the louvers,
filters, coils, electrical components and grilles. Use
compressed air, if available, to aid in cleaning.
c. Air Filters and Coils.
( 1 ) Under extremely dusty or sandy con-
ditions, the louvers, filters, coils, electrical com-
ponents and grilles must be serviced more often.
Note. Never operate the unit without having the air
filters in place.
( 2 ) The condenser coil is subjected to ambient
air. Therefore, it requires cleaning more often than
the evaporator coil.
2-15. Operation Under Rainy or Humid Con-
Take special precautions to keep equipment dry. If
installed outdoors, cover the equipment with a
waterproof cover when it is not in use. R e m o ve
cover during dry periods. Take all necessary
precautions to keep the electrical components free
Caution: Make sure power is disconnected
f r o m a i r c o n d i t i o n e r b e f o r e t o u c h i n g a ny
wiring or other electrical parts.
2-16. Operation in Salt Water Areas
a. General. Wash the exterior and condenser
section of the unit,
particularly condenser air
discharge louver control mechanism, with clean
fresh water at frequent intervals. Be careful not to
damage electrical system with water. Special at-
tention must be given to prevent rust and corrosion.
W a r n i n g : Disconnect power source prior
to washing the air conditioner.
b. Painting. Paint all exposed areas where paint
has cracked, peeled, or blistered or report condition
to organizational maintenance. Coat all exposed
areas of polished metal with a light coat of grease.