Section III. CONTROLS AND INSTRUMENTS

TM 5-4120-273-15

tion in crate fabrication. Provide suitable blocking

2-8. Reinstallation After Movement

and tie downs to prevent unit from shifting dur-

Reinstall the air conditioner as instructed in para-

ing transfer.

graph 2-5.

Section III. CONTROLS AND INSTRUMENTS

in the upper rear panel, covered with a thin piece

2-9. General

of rubber material directly in front of the switch

This section describes, locates, illustrates, and

for this reason.

furnishes the operator, crew or organizational

maintenance personnel sufficient information

c. Low Pressure Switch. The low pressure

about the various controls and instruments for

switch, located at the upper left rear of the unit

proper operation of the air conditioner.

(fig. 1-3), is designed to sense line pressure from

the compressor and will cutout at 25 psig. When

the line pressure has increased to 50 psig, the low

2-10. Controls and Instruments

pressure switch can be reset by pushing the reset

a. General. The purpose of controls and instru-

button in, with a pencil like object, and holding it

ments and their normal readings are illustrated

for approximately 2 to 3 seconds. There is a hole

in the upper rear panel, covered with a thin piece

b. High Pressure Switch. The high pressure

of rubber material, directly in front of the switch

switch, located at the upper left rear of the unit

for this reason.

(fig. 13), is designed to sense line pressure from

the compressor and will cutout at 445

d. Liquid Line Sight Glass. The sight glass

psig (pounds per square inch gage). When the

(fig. 1-3) indicates dryness of the system. Mois-

line pressure has reduced to 400 psig, the high

ture in the refrigerant is shown by the indicator

pressure switch can be reset by pushing the reset

turning from green to yellow. A shortage of re-

button in, with a pencil like object, and holding

frigerant is indicated by flash gas in the sight

if for approximately 2 to 3 seconds. There is a hole

glass.

2-5