Chapter 7. CONTROLS AND INSTRUMENTS

TM 5-4110-217-14

CHAPTER 7

CONTROLS AND INSTRUMENTS

Installation.

7-1. General.

(1) Attach switch (4) to frame with two screws

(5).

A general description of the control box assembly is

(2) Connect wires to proper terminals.

given in paragraph 3-55. Organizational maintenance

(3) Connect flare nut of high pressure control

may make most all repairs or replacement in the control

switch (4) to compressor.

box, or on its panel. Removal or replacement of the high

(4) Back seat suction and discharge service

pressure cutout switch or any repair or replacement of

valves, opening one turn for gage connection.

parts which require the opening of the refrigeration

(5) Refer to paragraph 6-9 and test for leaks.

system must be referred to Direct Support. 7-2. Control

(6) Apply power.

Box Assembly.

a. Removal (fig. 8-24).

7-4. High Pressure Gauge.

(1) Remove six screws (5) securing the

Removal fig. 6-2).

control box assembly (6) to the frame and carefully pull

out the assembly.

(1) Back seat discharge service valve (16, fig.

(2) Disconnect main wire harness at

6-1), and remove gauge line nut at back of high pressure

connector receptacle (30, fig. 3-23).

gauge (62).

b. Cleaning and Inspection.

(2) Remove three nuts (66) and washers (66)

(1) Clean all parts with a clean lint-free cloth

securing gage (62) to frame.

or compressed air.

(3) Remove fitting at back of gage. Do not

(2) Inspect parts for cracks, burning or other

remove fitting unless gage is to be replaced.

b. Cleaning and Inspection.

damage. Replace all defective parts.

c. Installation.

(1) Clean gage with a clean lint-free cloth.

(1) Align holes in control box assembly (6)

(2) Inspect for cracks, dents or other damage.

with holes in frame and secure with six screws (5).

Inspect all threaded parts for damage.

(2) Connect main wire harness connector

Replace if defective.

c. Installation.

plug to connector receptacle (30, fig. 3-23) located on

side of control box.

(1) Place high pressure gage (62) in hole of

refrigeration unit frame as in original configuration and

secure with three nuts (66) and washers (65).

7-3. High Pressure Control Switch.

(2) Replace fitting at back of gage.

(3) Screw gage line nut on fitting at back of

Removal fig. 6-2).

gage and turn valve stem of discharge service valve (16,

(1) Refer to paragraph 6-1 and pump down

fig. 6-1) until pressure registers on gage.

7-5.

refrigeration system.

Compound Pressure Gage.

(2) Turn off power source.

a. Removal (fig. 6-2).

(3) Front seat discharge and suction service

(1) Back seat the suction service valve (11,

valves.

fig. 6-1) and remove gage line nut at back of compound

(4) Remove flare nut of high pressure control

pressure gage (63).

switch (4) at compressor (1).

(2) Remove three nuts (66) and washers (65)

(5) Remove wires carefully labeling each for

securing gage (63) to frame.

proper terminal.

(3) Remove fitting at back of gage. Do not

(6) Remove two screws (5) attaching switch

remove fitting unless gage is to be replaced.

(4) to frame.

b. Cleaning and Inspection.

(1) Clean gage with a clean lint-free cloth.

(1) Clean switch with an approved cleaning

solvent and dry thoroughly.

(2) Inspect switch for dents, cracks, or other

damage. Replace if defective.

7-1