Piper Cherokee Six - Page 690

PIPER
CHEROKEE
SIX
SERVICE
MANUAL
e.
Connect
the
heating
element
plug
to
a
110
volt
outlet.
f.
Turn
cylinder
sight
glass
to
match
pressure
reading
on
cylinder
pressure
gauge,
this
scale
should
be
used
during
entire
charging
operation.
g.
Close
valve
(low
pressure
control),
fully
open
valve
(refrigerant
control)
and
allow
all
liquid
refrigerant
contained
in
the
charging
cylinder
to
enter
high
side
of
aircraft
system.
h.
When
the
full
charge
of
refrigerant
has
entered
the
system,
close
valve
(refrigerant
control)
and
valve
(high
pressure
control).
i.
After
completion
of
charging,
close
all
valves
on
the
charging
stand.
Disconnect
the
high
and
low
pressure
charging
lines
from
the
aircraft
system.
(A
small
amount
of
refrigerant
remaining
in
the
lines
will
escape.)
Replace
lines
on
holder
of
charging
stand
to
keep
air
and
dirt
out
of
lines.
Open
the
valve
at
the
top
of
cylinder
to
relieve
any
remaining
pressure,
then
reclose
the
valve.
i.
Reinstall
protective
caps
of
Schrader
valves
and
any
access
panels
previously
removed.
13-16.
USING
THE
AIRPLANE
COMPRESSOR
TO
CHARGE
THE
SYSTEM.
This
method
is
the
least
desirable
due
to
the
requirement
of
operating
the
airplane's
engine
to
run
the
compressor.
CAUTION
Ascertain
that
the
area
around
the
airplane
is
clear
and
a
qualified
person
is at
the
controls
of
the
airplane.
a.
With
the
system
evacuated
as
outlined
in
paragraph
13-13,
connect
the
refrigerant
charging
hose
to
the
manifold
(refer
to
Figure
13-8)
and
purge
the
charging
hose
of
air.
b.
Place
the
refrigerant
container
on
a scale
to
observe
the
amount
of
refrigerant
entering
the
system.
Open
the
high
pressure
valve
and
add
as
much
refrigerant
as
possible.
c.
Close
the
high
pressure
valve,
start
the
engine
and
operate
it at
900
to
1000
RPM
ith
the
airplane
heading
into
the
wind.
d.
Operate
the
air
conditioner
and
set
controls
to
maximum
cooling.
e.
Open
the
low
pressure
valve
and
complete
charging
the
system.
f.
Close
the
low
pressure
valve
after
two
pounds
of
refrigerant
have
been
added
to
the
system.
g.
With
the
system
still
operating,
observe
the
sight
glass
in
the
top
of
the
receiver-
dehydrator
by
removing
the
plastic
plug.
h.
The
sight
glass
should
be
clear
of
any
bubbles
or
foam.
If
bubbles
or
foam
are
seen
passing
through
the
sight
glass,
it
is an
indication
of
a low
refrigerant
charge
in the
systee
and
more
refrigerant
is
required.
This
check
should
be
made
with
OAT
of
70°F
or
higher
and
with
the
air
conditioner
operating.
i.
If
more
refrigerant
must
be
added
to
the
system,
open
the
low
pressure
valve
and
increase
engine
speed
to
2000
RPM
and
observe
the
sight
glass.
After
the
sight
glass
has
cleared,
close
the
low
pressure
valve
and
observe
the
pressure
gauges.
At
1000
RPM
the
gauge
pressure
should
be
15
to
20
psi
on
the
low
side
and
150
to
200
on
the
high
side.
Revised:
11/4/83
ACCESSORIES
AND
UTILITIES
3G24