Mooney M20R - Refrigerant Charging Procedure

SERVICE
AND
MAINTENANCE
MANUAL
M20R
M
OON EY
Al RC RAFT
CORPORATION
6.
Open
both valves
on
charging
manifold
and
observe
7. Move
aircraft
to
run-up
area.
gauges.
8.
Start aircraft
engine.
Select "MA>C’
on
airconditioner
NOTE
switch. Idle
aircraft
engine
at
800--900
RPM.
Veryify
Low
pressure
gauge
’BLUE’:
will indicate
vacuum
Alternator is
charging.
onlower
railge
of
gauge.
CAUTION
7. Evacuate
system
for
30
full
minutes.
System
vacuum
Do
not
operate
system
with
high~pressure
(RED)
valve
open
on
the
charging
manifold
gauge
set.
should
attain 25
27
in.
hg.
in 10 to
15 minutes.
8.
Close
manifold
valves
and shut
vacuum
pump
OFF.
9.
With
system
operating,
observe
the
system
dis-
Vacuum
in
system
must not
change
within 5
minutes,
charge
and
suction
pressure
values
and
refrigerant
con-
dition in
the
receiver-dryer
sight
glass.
CAUTION
Any
change
in
vacuum
pressure
or
failure
to
NOTE
achieve
a minimum
system
pressure
of 29
in.
hg.
A
flashlight
and
inspection
mirror
are
required
during
vacuum
indicates
the
presence
of
a
plumbing
lea~k.
the
sysfem
charging
procedure.
Excessive
bubbles
Repeat
leak
check
procedure;
locate
and
repair
all
in the
slgntglass
indicate
a
low
refrigerant
level.
leaks.
10. V~th the
R-l
34a
cylinder
connected
to
the
charging
9.
Disconnect
manifold
yellow
service
hose.
System
is
hose,
charging
container
shutoff valve
open
and
hose
ready
for
refrigerant
charging.
purged,
slowly
open
the
suction
manifold valve
(BLUE).
The suction
pressure
will increase
to
60-70
PSIG
while the
NOTE
R-134a
refrigerant
enters
the
compressor.
Excessive
water
and/or air
in the
system
will
cause
pressure
to
riselexpansion
valve
freeze-up.
NOTE
As
refrigerant
enters
the
compressor
a
slight
2152-03
REFRIGERANT
CHARGING
increase
in
discharge
pressure
will
de
noted
PROCEDURE
(2
PSIG).
Charging
the
system
with
refrigerant
is
required
on a new
11. Continue
to
add
refrigerant
per
the above
proce-
system
installation
or
when
’Yopping
off’
an
existing
sys-
dure until the
sightglass
is clear of excessive
bubbles
tem.
There
are
various
methods
of
charging
refrigerant
when
charged
on a
hot
day
(95-1050
Fl.
into
the
air
conditioning system.
These
include
using
NOTE
refrigerant
recovery/recycle
units,
using
a
charging
cylin-
A desired
sightglass
liquid
condition is when
only
der,
and
direct
charging
using
a
scale.
Refer
to
manufac-
occasional
bubbles
are
observed when
charging
turers
instruction
manual
for
recovery
unit
handling
and
on a
hot
day (95
105"
Fl.
operation.
1.
Verify
that all
electrical
power
to
the
system
is OFF.
12.
Close
suction manifold valve
(BLUE)
and let
sys-
tem
operate
for 5-10
minutes and then check
sightglass.
2. If
required,
repeat
leak check
and evacuation
procedures.
If
sightglass
is
not
totally
clear,
open
suction
manifold
valve
and add
a
small
quantity
of
refrigerant
until 98% of
CAUTION
bubbles
disappear.
Close
manifold
valve
and let
system
Eye
and hand
protection
must
be
worn
during
this
stabilize.
procedure.
NOTE
3. Connect
manifold
charging
hose
(yellow)
to
R-134a
Letting
the
system
stabilize is
required
since the
cylinder
shutoff
valve
and
open
valve,
expansion
valve
is
trying
to
stabilize
to
the
preset
4.
Crack
hose
fitting
at
manifold
to
purge
air from
hose.
suction
pressure
value.
If
system
refrigerant
charge
is
to
be
recorded,
place
CAUTION
refrigerant
container
on a
0- 50 Ib.
scale and
record initial
Do
not
overcharge
system
or component
and
system
damage
may
occur.
Full
svsfem
charge
is
weight.
approximately
3.2 Ibs. of
R-134a.
5.
Open
both
manifold
gauge
valves
and allow
refrig-
erant
gas
to enter
system.
Continue
adding
refrigerant
13.
V~th
the
system
fully charged
and
operating,
ob-
until
system
internal
pressure
has stabilized.
serve
the suction
and
discharge
pressures.
Typical
val-
ues
at
vario
us
ambient
temperatures,
with
hot
cabins,
are
6. Close
manifold
valves
and
verify
system
internal
shown
below:
pressure
is
50
PSIG
or
greater.
NOTE
If
internal
pressure
is
not
above
50
PSIG,
the low
pressure
cutout
switch
will
not
close.
To
assure
an
internal
pressure
of 50
PSIG,
the
R-134a
cylinder
must
be
heated
to
obtain
a
charge
pressure
of
70
-80 PSIG.
CAUTION
Do
not
heat
R-134a
container
with
open
flame
or
container
damage
may
result
and
possible
injury
to
operator.
Heat
with
warm
water
or room
temperature.
Do
not
store
or
heat
refn~gerant
Container
at
temperatures
above
125"
F.
REV. 7-96
21-52-03
Island Enterprises