Compressor Starts But Goes Out on Overload

TM 5-4120-273-3-15

Possible remedy

Probably cause

Possible remeby

Probable cause

Burned out heater

Replace heater element (s)

Reset circuit breaker

Circuit breaker contacts

(fig. 2-11 or 3-12).

open

(fig. 2-2).

element(s)

Contacts of high or low

Push reset button to reset

3-15. Suction Pressure Inadequate

pressure switch open

pressure switch. (fig.

1-3), hold 2-3 seconds.

Possible remedy

Probable cause

Inadequate air flow across

Check fan for tightness on

3-13. Compressor Starts But Goes Out on

evaporator coil

shaft. Clean evaporator

Overload

coid and filter (para 3-55c

Probable cause

Possible remedy

and 3-9b).

Condenser fan not

Check motor and motor

Reset thermostat (fig. 2-3).

Air temperature in con-

leads.

operating

ditioned space excessively

Condenser coil blocked ----- Clean condenser coil

low

(para 3-56c).

3-16. Low Suction and Discharge Pressure

3-14. Little or no Heating Capacity

Possible remedy

Probable cause

Prabable cause

Possible remedy

Lack of refrigerant -------- Check sight glass for

Seleector switch improperly Set switch to proper setting.

appearance of flash gas.

set

(fig. 2-3).

(fig. 3-14). Beport low

Clean the air filter, evapora-

Air movement over

refrigerant charge to

tor coil (para 3-9b, and

evaporator insufficient

direct support mainte-

3-55c).

nance.

Improper electrical

Check all heater wiring

Clogged air filter _____ Clean filter (para 3-9b).

(para 5-22).

connections

Section VI. HOUSING ASSEMBLY

b. Inspection and Repair. Inspect for minor

3-17. General

dents and cracked or chipped paint. Repair minor

The air conditioner is constructed with removable

damage, repaint.

aluminum panels. The front access panel provides

c. Installation. Refer to figures 3-4 and 3-6 to

access to the junction box, control panel, and

install panels and grilles.

access fittings. A discharge grille protects the

evaporator and controls the direction of discharge

3-19. Canvas Condenser Cover

of conditioned air. The intake grille protects the

a. Removal. Remove retaining hardware and

air conditioning filter and regulates the amount

lift off cover. Refer to figure 1-3.

of air returned to the unit. The condenser coil

b. Inspection and Repair. Inspect cover for rips

grille and fan guard protects the condenser coil

or tears. Repair with waterproof tape.

and fan. A fresh air inlet screen permits the entry

c. Installation. Place cover in position and se-

of outside air and is controlled by the damper door

cure with retaining hardware.

with the control spring and chain. The cover panel

3-20. Fresh Air Inlet Screen, Chemical and

covers the top of the unit.

Biological Inlet Cover, Condenser Fan

Warning: Disconnect the air conditioner from

Guard and Condenser Coil Grille

the power source before performing any mainte-

a. Removal. Refer to figure 3-4 and 3-5, and

nance on the components of the unit.

remove fresh air inlet screen, CB (chemical and

biological) inlet cover, condenser fan guard, and

3-18. Top Panel, Discharge Grille, Intake

condenser coil grille.

Grille, and Front Access Panel

b. Installation. Install the fresh air inlet screen,

a. Rmoval. Refer to figure 3-4 and 3-5 re-

CB inlet cover, fan guard, and condenser coil

move panels and grilles.

grille and screen. Refer to figures 3-4 and 3-5.

Section VII. GENERAL ORGANIZATIONAL MAINTENANCE

INSTRUCTIONS

3-21. Compressor

3-22. Evaporator Fan and Inlet Ring

(fig. 3-6)

a. General. Models CV-6-1-15-60 and CV-

Test for continuity across motor windings with

6-3-08-400 are equipped with a centrifugal in-

multimeter set on OHMS. Refer to the wiring dia-

clined blade evaporator fan. The fan reduces ex-

grams figure 1-5 to establish points of conti-

cessive vibration and noise.

nuity.

3-9