TB-9-2320-279-13-1

TECHNICAL BULLETIN; AIR CONDITIONING SYSTEM

OPERATOR’S, UNIT AND DIRECT SUPPORT MAINTENANCE MANUAL, INSTALLATION INSTRUCTIONS, AND REPAIR PARTS AND SPECIAL TOOLS LISTS

DECEMBER 2005

TB-9-2320-279-13-1 - Page 184 of 524

TB 9-2320-279-13-1

0015-16

AC DOES NOT COOL OR COOLS INADEQUATELY - Continued

DRAFT

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KNOWN INFO

Power to AC system OK.

AC heater/evaporator blower OK.

AC control circuits OK (except for

temperature control and low pressure

switches).

AC low pressure switch OK.

No AC condenser dryer desiccant

contaminant in AC refrigerant system.

No AC refrigerant oil contaminant in AC

refrigerant system.

AC system charge is not low.

No AC system leaks.

Temperature control switch OK.

No air or other contaminant in AC refrigerant

system.

POSSIBLE PROBLEMS

Restricted AC hoses.

AC compressor faulty.

AC condenser core faulty.

Moisture in AC refrigerant system.

AC expansion valve faulty.

AC system overcharged.

AC condenser dryer faulty.

AC evaporator core faulty.

10.

Does AC test set recovery/

recycling manifold gages

indicate high system low-side

pressure?

Go to Step 16 of this

fault.

NO

YES

Read WARNING on

page 0015-17.

WARNING

TEST OPTIONS

Pressure test.

AC test set manifold gage.

REASON FOR QUESTION

To isolate system fault.

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KNOWN INFO

Power to AC system OK.

AC heater/evaporator blower OK.

AC control circuits OK (except for

temperature control and low pressure

switches).

AC low pressure switch OK.

No AC condenser dryer desiccant

contaminant in AC refrigerant system.

No AC refrigerant oil contaminant in AC

refrigerant system.

AC system charge is not low.

No AC system leaks.

Temperature control switch OK.

No air or other contaminant in AC refrigerant

system.

AC condenser dryer OK.

AC evaporator core OK.

POSSIBLE PROBLEMS

Restricted AC hoses.

AC compressor faulty.

AC condenser core faulty.

Moisture in AC refrigerant system.

AC expansion valve faulty.

AC system overcharged.

11.

Does AC test set recovery/

recycling manifold gages

indicate high system high-

side pressure?

Go to Step 14 of this

fault.

NO

YES

Read WARNING on

page 0015-17.

WARNING

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TEST OPTIONS

Pressure test.

AC test set manifold gage.

REASON FOR QUESTION

To isolate system fault.