TM 9-4120-385-14
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 to the left of the fan
guard.
2 - 5 . OPERATION IN EXTREME COLD
a. GENERAL. The air conditioner is designed to operate on the heating cycle in ambient
temperatures as low as 50 F (-45.5 C) and on cooling cycle with 0 F (18 C) air entering the
condenser and 70 F (21 C) air entering the evaporator.
CAUTION
Do not disturb wiring during cold weather unless absolutely
necessary. Cold temperatures make wiring and insulation brittle
and easily broken.
b . BEFORE OPERATION.
(1) Before starting on cooling cycle, be sure cover is rolled from condenser air intake
and discharge.
(2) Clear all ice and snow from openings.
(3) To start unit on COOL mode below 0F (18C) ambient (mini mum operating
temperature), contact organizational maintenance.
c. AFTER OPERATION. Install cover over condenser air intake and discharge openings.
2 - 6 . 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 120 F
(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.
