Specifications

8.
Purge the temporary
ref rigerant
charge out the low
side.
This
will help
to
remove
moisture from
the system.
Keep
in
mind that the
process
of
flushing clean refrigerant
through the
system is equivalent
to 20 or 25 min-
utes of
pulling
a vacuum with
a
vac-
uum
pump
of lower
capacity than
those specified. Therefore,
you
can
induce
another temporary
charge and
purge,
if
you
desire.
9. Repeat the vacuum
pump procedure
for
another 30 minutes
which
should
again
pull
down to about
500 microns
or 29.6 inches
of mercury.
IMPORTANT:
Always
heat
as
much
of the
system
as
you
can while
evacuating,
pref-
erably with
a heat
lamp
-
not
a torch. Be
careful with the
lamp, however,
to
avoid
damaging
any nearby
plastic parts
or
sys-
tem
parts.
RECHARGING
lt
is very
essential
that
you
have the
proper
eguipment
when
charging the
sys-
tem
so
you
can
be accurate to within
1/4
ounce of refrigerant.
Although there
are
several methods
of charging, we
recom-
mend the
use
of a sight
glass
charging
cylinder which is
accurate
regardless
of
the
ambient
temperature.
We recommend
when
using the
vacuum
pump
evacuating
procedure,
that
you
charge through
the low
side of the
system,
either through the
process
tube
or the
suction line.
Remember,
however,
that
the ref
rigerant
should
be introduced
slowly. Because
the refrigerant
will
enter
the
system in
a liquid
state,
you
should
never run
the
compressor
while
charging.
Wait
at
least
5 minutes
after
the
charge
has entered
before starting the
compres-
sor.
1.
Connect the hose
of the
charging
cyl-
inder
to the
system through
a
gauge
manifold
as shown in
previous
draw-
ing.
Close valve
"A"
on the manifold.
2. Open the
charging cylinder
and
purge
the hose.
As
soon as the refrigerant
has
stabilized
in the
charging cylinder,
check the
pressure
reading
of the
cyl-
inder
and rotate
the
sleeve
to
correct
the
setting
for
pressure
and the type
of
refrigerant
being
used.
3. Consult
Section
9
for
the
amount of
charge needed,
then
open valve
"8".
As
you
charge
the system,
you
may
notice
some bubbles in
the cylinder.
These
can
be eliminated
by closing
your
service valve
and tipping the
cyl-
inder
upside-down
momentarily.
Then
continue
charging
until the
correct
charge has
entered the
system.
lf
at
any time
you
are required
to raise
the
internal
pressure
of the
charging cylinder,
or if
your
charging
cylinder
does not have
an
internal
heater,
place
the
cylinder in
a
bucket
of
warm
water
(not
over 125o F).
Never
heat
a charging
cylinder
with
a
flame.
Such
action
could
cause hydros-
tatic
pressure
to
build up to
dangerous
levels
and
possibly
cause the
cylinder
to
rupture
iike
a bomb.
4.
When
you
are
sure the
system is
cor-
rectly
charged,
stop the
flow
of refri-
gerant
at
valve
"B".
Then
pinch
off the
low
side
process
tube,
close the
charging
cylinder
valve,
remove
the
service valve,
and
solder
the
process
tube
closed.
3-13