------------
Rolls-Royce &
Bentley-------
Air
Conditioning
System
Manual
SECTION C.6
SERVICING
SPECIAL TOOLS REQUIRED
Part
No. Description
Number
off
RH.527 'Blaydon' leak detector lamp,
or
similar model
RH.528
Tube
flaring tool
RH.529 Spring balance, 0-25 lb.
RH.530 Thermometer
RH.531 Spanner, ring, l.125
A/F
X 0.875
A/F
RH.532 Spanner, ring,
0.75Q
A/F
X
LOO
A/F
I
RH.533 Wrench, ratchet, 0.250 square 1
RH.534
Tube
cutting tool I
RH.538 Manifold gauge set assembly l
Also: A pair
of
goggles
and
a First-Aid kit con-
taining medicated liquid paraffin, and saline wash.
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 first-aid treatment is necessary
and
a doctor
or
eye specialist should be consulted
as soon as
is
possible.
Fir&t-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 tempera-
ture relationship
of
pure Freon
12.
So long as
the
system contains only pure Freon
12
(plus a certain
amount
of
compressor lubricant which mixes with
the Freon), it is considered
to
be chemically
stable.
Wlten 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
break a
refrigerant connection, the exposed
ends
should
be immediately capped. Air entering the system
will carry moisture, which collects quickly
on
any
exposed surface, causing deterioration, owing to
the acidic properties
of
an air-Freon compound.
FAULT
DIAGNOSIS
In
order
to
facilitate fault diagnosis,
the
unit
may be considered as two
separate
systems,
viz. the
air
delivery system
and
the refrigerant
circulation system; these
should
be checked
independently.
The
upper
and
lower airstream
switches individually control
air
delivery through
the fresh air
and
recirculated
air
ducting
respectively.
Pagel)
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