Section III. Operation Under Usual Conditions

TM 5-4120-339-14

2-3.

GENERAL.

a. The instructions in this section are for the information and guidance of personnel responsible for the operation

of the air conditioner.

b. The operator must know how to perform every operation of which the air conditioner is capable. This section

gives instructions on starting and stopping the air conditioner, basic motions of the air conditioner, and on coordinating

basic motions to perform specific tasks for which the equipment is designed.

c. Although the air conditioner is normally used for mechanically cooling and heating the control space

automatically, it may also be used to ventilate only. Care should be taken to insure that doors to the conditioned space

close with a good seal against the ambient (outside) air. Frequent door opening will impose an abnormal load on the air

conditioner, preventing normal on and off cycles.

d. The operator must be observant at all times, particularly concerning unusual sounds that would indicate

malfunctioning of the air conditioner. When unusual sounds occur, stop operation and report to Organizational

Maintenance.

2-4.

OPERATION.

a. Preparation for Starting.

(1) Make sure that the air conditioner cover is unzipped and rolled up, and that the retaining straps are

attached to the top.

(2) Refer to paragraph 2-2 and perform the daily preventive maintenance checks and services.

(3) Make sure that the air conditioner is connected to a 208 volt, 3-phase 50/60 Hz electrical power source.

(4) Make sure that none of the air openings of the air conditioner are blocked.

b. Starting. (Refer to figures 2-1 and 2-2.)

(1) Cooling operation.

(a) Position thermostat for desired temperature.

(b) Place fan speed toggle switch in desired position.

(d) For cooling with 100 percent recirculated air, close damper door.

(e) For cooling with a mixture of recirculated air and fresh air, open damper door and partially close

intake grille damper.

2-4