CJO
Air
Conditioning
System
Manual
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Rolls-Royce
& Bentley
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PRECAUTIONS
TO
BE
OBSERVED
WHEN
HANDLING
REFRIGERANT
Exposure to Refrigerant
Large quantities
of
refrigerant gas discharged into
a confined space will displace the oxygen
in
the
air
and
could
cause suffocation.
Liquid refrigerant which may accidentally escape
is
at
least 20"F. below zero
and,
if
allowed
to
come into
contact
with the skin, it
can
cause a burn by the
rapid
transference
of
heat from the skin
to
the liquid
as
it evaporates. Serious
damage
to
the eyes will
result from
contact
with liquid refrigerant.
For
this
reason, goggles should always be
worn
when
contact
might be possible.
Should
liquid refrigerant
come
into
contact
with
the eye, immediate Firs, A id is necessary
and
a
doctor
or
eye specialist should be consulted
as
soon
as
possible.
:First
Aid
Treatment
Medicated liquid paraffin from the First Aid
Kit
should
be applied
to
the eye from
an
eye
dropper,
to
wash
away
the Freon.
The
eye should not be rubbed,
as this will increase the
area
of
injury.
If
the eye
remains painful
after
a few minutes. the wash should
be repeated. using a sterile salt solution
containing
not
more
than
2 %
sodium
chloride.
The Importance
of
Chemical Stability
The
efficient
operation
of
the system
is
dependent
upon
the Pressure-Saturation
Temperature
Relation-
ship
of
pure
Freon
12.
So long as the system
contains
only
pure
Freon
12
(plus a certain
amount
of
conc-
pressor lubricant which mixes with the i:reon). it
is
considered to be chemically stable.
When foreign materials such as dirt.
air
or
moisture
are
allowed to
enter
the system. they will affect
chemical stability.
change
the Pressure-Saturation
Temperature
Relationship
of
the Freon.
and
possibly
cause freezing up
of
the expansion valve. Thus. the
system will
no
longer
operate
at
the correct pressures
and
temperatures, with a consequent decrease
in
efficiency.
The Sealing
of
Components
Whenever
it
becomes necessary to
hreak
a refri-
gerant
connection, the exposed
ends
should
be
immediately capped. Air entering the system will
carry
moisture, which collects quickly
on
any
exposed
Secrio11
C6
surface, causing
deterioration,
owing to the acidic
properties
of
an
air-Freon
compound.
FAULT LOCATION
For
the purpose
of
complaint
diagnosis, the system
falls into two groups.
I . Air Circulation
2. Refrigerant Circulation
AIR CIRCULATION
Switch
on
and check
air
delivery
at
the
duct
outlets.
Check
over
the full range
of
blower speeds.
A failure on
one
side only would be
due
to
either
a defective blower
on
that
side
or
a defective connec-
tion between the
push-button
switch
and
the blower
motor.
A failure
in
one
switch position only would be
due
to a defective switch.
A complete failure indicates a fuse, switch
or
wiring
defect.
REFRIGERANT CIRCULATION
Initial Checks
Site rhe
car
in
a well ventilated
and
shaded
area.
Check
the belt tension
and
the external cleanliness
of
the condenser,
as
detailed
under
'MAINTENANCE'.
Start
the engine
and
warm-up
at
a fast idle. operating
the Air
Conditioning
system with the blowers full
on. Visually check
that
the magnetic clutch
is
operating.
Observe the sight glass located
adjacent
to the
filter
drier
(this
is
either
located
adjacent
to the
receiver
or
in some instances
adjacent
to the eva-
porator
assembly). If bubbles
or
foam
appear
in
the
sight glass, the refrigerant
is
low. Also, a distinct
continuous
or
intermittent hiss from the expansion
valve
in
the
boot
indicates
that
vapour
is
hcing passed
through the valve
and
that
the refrigerant charge
is
low. In either case check the system for leaks. (See
Section
on
Leak Detection).
lee formation
adjacent
to the
compressor
intake
is
an
indication
of
excessive delivery
through
the
expansion valve. this can be caused by a faulty
expansion valve.
A partial blockage will
create
a
drop
in
temperature
at
the
point
of
restriction in a
hot
vapour
or
liquid
line,
or
across the receiver
or
filter-drier assembly, ~nd
this will be obvious to the
touch.
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