Komatsu 930E-2, Руководство по ремонту

Страница: 539 / 739

SYSTEM SERVICING
Servicing an air conditioning system really means
closely monitoring refrigerant flow. For this reason,
the following procedures deal extensively with the
proper use, handling, care and safety factors involved
in the R-134a refrigerant quality and quantity in an air
conditioning system.
Because the refrigerant in an air conditioning system
must remain pressurized and sealed within the unit to
function properly, safety is a major consideration when
anything causes this pressurized, sealed condition to
change. The following warnings are provided here to
alert service personnel to their importance BEFORE
learning the correct procedures. Read, remember, and
observe each warning before beginning actual system
servicing.
NOTE: If the mine operates a fleet with some trucks
using R-12 and others using R-134a refrigerant, it is
essential that servicing tools that come into contact
with the refrigerant (gauge sets, charging equipment,
recycle/recovery equipment etc.) be dedicated to one
type refrigerant only, to prevent cross contamination.
Federal regulations prohibit venting R-12 and
R134a refrigerant into the atmosphere. An SAE and
UL approved recovery/recycle station must be
used to remove refrigerant from the AC system.
Refrigerant is stored in a container on the unit for
recycling, reclaiming, or transporting. In addition,
technicians servicing AC sytems must be certified
they have been properly trained to service the
system.
Although accidental release of refrigerant is a re-
mote possibility when proper procedures are fol-
lowed, the following warnings must be observed
when servicing AC systems:
Provide appropriate protection for your eyes (gog-
gles or face shield) when working around refriger-
ant.
A drop of the liquid refrigerant on your skin will
produce frostbite. Wear gloves and exercise ex-
treme care when handling refrigerant.
If even the slightest trace of refrigerant enters in
your eye, flood the eye immediately with cool water
and seek medical attention as soon as possible.
Ensure sufficient ventilation whenever refrigerant
is being discharged from a system, keeping in
mind refrigerant is heavier than air and will seek
low areas of shop.
When exposed to flames or sparks, the compo-
nents of refrigerant change and become deadly
phosgene gas. This poison gas will damage the
respiratory system if inhaled. NEVER smoke in area
where refrigerant is used or stored.
Never direct steam cleaning hose or torch in direct
contact with components in the air conditioning
system. Localized heat can raise the pressure to a
dangerous level.
Do not heat or store refrigerant containers above
120° F (49° C).
Do not flush or pressure test the system using shop
air or another compressed air source. Certain mix-
tures of air and R-134a refrigerant are combustible
when slightly pressurized. Shop air supplies also
contain moisture and other contaminants that
could damage system components.
R-134a Refrigerant Containers
Two basic, readily available containers are used to
store R-134a: the 30 or 60 pound bulk canisters (Figure
9-2).
Always read the container label to verify the contents
are correct for the system being serviced. Note the
containers for R-134a are painted light blue.
FIGURE 9-2. R-134a CONTAINERS
1. 30 Pound Cylinder 2. 60 Pound Cylinder
M09010 6/97 Air Conditioning System M9-7
for HFC 134a Refrigerant