OPERATION UNDER UNUSUAL CONDITIONS - TM-9-4120-428-140039

TM 9-4120-428-14

OPERATOR'S MAINTENANCE

AIR CONDITIONER, HORIZONTAL, COMPACT

(NSN 4120-01-502-1319)

OPERATION UNDER UNUSUAL CONDITIONS

GENERAL

The Keco model F9000H-4SPFI air conditioners are designed for operation in a wide range of climatic conditions. However,

some extreme conditions require special operating and servicing procedures to prevent un-due loading and excessive wear on

the equipment.

CAUTION

Prior to operation ensure that the condenser louver in the rear of the unit is closed when

the outside ambient temperature falls below +50F (+10C).

Before Operation

Before starting operation, be sure canvas cover is rolled up and secured. Clear all ice and snow from openings. Be sure all

dampers are in operating condition.

After Operation

Roll down and snap on canvas cover over condenser intake and outlet.

CAUTION

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

make wiring and insulation brittle and easily broken.

NOTE

The fabric cover must be rolled up when operating in the cooling mode or when the unit

is connected to a NBC filter. The fabric cover may be rolled down and snapped in place

during other modes of operation as appropriate for environmental conditions.

The fresh air damper should be positioned fully closed whenever the fabric cover is rolled

down and secured since outside air cannot be drawn in through the fresh air inlet screen.

Under normal operating conditions, before starting the air conditioner in any mode, make

sure that the fabric cover on the back of the cabinet is rolled up and secured, that the

condenser fan intake screen and fan guard are in place and unobstructed, and that the

evaporator fan intake and discharge grille louvers are fully open. EXCEPTIONS: Under

extreme climatic conditions, such as blowing snow, which might enter the compressor

section, the unit may be operated in the VENT, LOW HEAT or HIGH HEAT mode with

the fabric cover rolled down and snapped in place. When operated in this manner, outside

air cannot be drawn through the fresh air damper, which should be positioned fully

closed. The fabric cover cannot be rolled down if the unit is connected to a NBC filter.

Do not operate in the cool mode with the fabric cover rolled down.

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