Specifications

EVACUATING
AND RECHARGING
The
following
general
information
applies
to all systems
covered
in
this manual.
EVACUATING
Any
time the sealed
system
is opened
and
the refrigerant
charge
removed,
you
must
install a
new service
drier and
thoroughly
evacuate
before
recharging.
Even
though
a complete
evacuation
takes additional
time,
it will save
time
in the long
run.
1.
Open
the compressor
low side
proc-
ess
tube as close
to the
pinched
end
as
possible.
This will
leave sufficient
room
for
pinching
off
at the conclu-
sion.
2. Install a service
valve on
the
process
tube.
3. Connect
your
vacuum
pump
to the
service
valve through a
gauge
mani-
fold
as shown.
Leave
the service
valve
closed. Use a
good
vacuum
pump,
one
in which
you
change oil often
for
the
most
eff
icient operation.
4. Start
the vacuum
pump
and open
its
discharge
valve.
Then slowly open
its
suction
valve and the service
valve on
the compressor
process
tube.
CAUTION:
lf
you
are using an
extremely
efficient
vacurlm
pump,
just
crack
its
suc-
tion valve
for the f irst minute
-
then slowly
open it. This
will
prevent
the
system
oil
from foaming and being
drawn into
the
pump
in
large volume. lf
this
should
hap-
pen,
the system oil,
containing
trapped
refrigerant, will
contaminate
your pump,
and, of
course, reduce the amount of
oil
in
the compressor.
5.
Pull
a
vacuum for about
20 minutes
-
this should
give
you
a
reading of
near
500
microns, or 29.6
inches of vacuum
on
a compound
gauge.
After
pulling
a
vacuum for 20
minutes,
you
can close
off
the valve of the
pump
while leaving
the
micron
gauge
in the system.
Then
observe the micron
gauge
(or
com-
pound gauge)
for a few minutes.
lf the
reading rises,
you
could
have a leak
in
the system.
EXTERNAL
VACUUM
PUMP
SYSTEM
COMPRESSOR
GAUGE
MANIFOLD
6.
7.
Close the manifold
valve
"A"
and
stop
the vacuum
pump.
Connect
your
sight
glass
charging
cyl-
inder to the
gauge
manifold and, after
purging
the line, open
valve
"B"
and
induce
a
charge of
refrigerant into the
system
until it
is
pressurized
to 35 or
40 P,S.l.G.
Then leak test the
low
side.
After leak testing
the low side,
run the
compressor
for a
few minutes and leak
test the
high
side.
3-12