TM 5-3805-291-23-1
AIR CONDITIONING SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0018 00
WARN I N G
Injury to personnel can resultfrom contact with refrigerant.
This system is under pressure at all times, evenif engine is not running. Heat should never be
applied to a charged system.
Contact with refrigerantcan cause frost bite. Keep face and hands away to help prevent injury to
personnel.
Protective goggles must always be worn when refrigerant lines are opened, even if gages indicate
system is empty of refrigerant.
Always use caution when a fitting isremoved. Slowly loosen fitting. If system is still under pres-
sure, evacuate system recovering refrigerant before removing fitting.
Injury or death to personnel can result from inhaling refrigerant through a lit cigarette.
Inhaling AC refrigerant gas through a lit cigarette or other smoking method or inhaling fumes
released from a flame contacting AC refrigerant gas, can cause bodily harm or death to person-
nel.
Do not smoke when servicing AC or wh never refrigerant gas may be present.
e
Before any checks of AC and heaing system are made, move machine to a smooth horizontal sur-
t
face. Lower all implements to ground. Make sure transmission is in neutral or park and parking
brake is engaged. Keep all other personnel away from machine or where they can be seen.
CAU T I ON
Low refrigerant charge will cause a loss of cooing ability and a loss of lubrication in compressor,
l
which will result in failure of compressor. Too much oil in system will contribute to a low refriger-
ant charge. Too much oil in system will contribute to a low refrigerant charge.
Overcharge of refrigerant will ca se a loss of cooling ability. A system that is overcharged will
u
contain excess liquid refrigerant, which will severely damage compressor. An overcharged system
will fail two times faster than an undercharged system. Too much oil in system will contribute to a
low refrigerant charge.
N OT E
A small amount of moisture will penetrate hoses used in R-134a systems. Change dryer and change accu-
mulator and desiccant annually. Moisture causes sludge and moisture results in plugged systems. Moisture
also causes formation of ice at orifice tube assembly.
Gage readings for an undercharged R-134a system may appear as symptoms of over-
charge under certain conditions. This occurs when ambient temperature is above 90F
(32C) or in high humidity. Gage readings that are incorrect lead to a loss of cooling abil-
ity and failure of compressor.
Refrigerant removed from a sytem cannot be weighed accurately. A 20 to 30% error can
s
occur. Error is a result of oil removed from system and a result of inaccuracies of equip-
ment used for recovery.
After recovering a system, if system pressurerises above 0 psi (0 kPa) within 5 minutes,
system must be recovered again until pressure does not increase. Recovering system
again will empty accumulator of refrigerant.
0018 00-2
