Specifications
LEAK TESTING
The
following
general
information
ex-
plains
several methods
of checking the
refrigeration
system
for
leaks. This infor-
mation
applies to
all systems covered in
this
manual.
lf there
is an undercharge
of
refrigerant
and the system has
not
been recently
opened, there is
probably
a leak in the
system. In that
case, it would
be only a
temporary
solution to
add
ref
rigerant
without
first locating
and repairing
the
leak
since
adding refrigerant
will not
per-
manently
correct the
difficulty.
The leak
must
be
located
and repaired
if
possible,
after which
the
entire system must
be
re-
charged
with the
proper
amount of refri-
gerant.
Whenever
a new
charge
of
refrigerant
is
added, it is
necessary
to in-
stall
a
new
drier.
Any
leak, regardless
of its
size, must
be
located
before
you
can
determine the
op-
erative
status
of the
system
components.
Do
not replace
a
component
because the
system is
short
of refrigerant
unless
a
non-repairable
leak
is found.
lf
your
analysis
indicates
a leak, find
it
before
opening the
system.
You
are more
likely
to
pinpoint
the
leak
before
dis-
charging
than if the
surrounding
air is
contaminated
with ref
rigerant
f rom
a
newly
opened
system.
The
presence
of oil
around a tubing
joint
usually indicates
a leak,
but don't let this
be the determining
factor.
Always
check
the area with
a
leak
detector
to make
sure.
To simplify leak
detection, keep
the sys-
tem
pressurized
to
a minimum
of 75 P.S.l.
This is
easily
accomplished
for high
side
testing
by merely running
the
compressor.
To
pressurize
the low
side,
allow the en-
tire
system to
warm
up to room temper-
ature.
Often
enough
refrigerant
may have
es-
caped to make it
impossible
to raise
the
pressure
enough to leak
test effectively.
In
cases of this
nature,
clamp a
piercing
valve to the
compressor
process
tube and
add enough refrigerant
to conduct the
test.
Leak
testing with
a Halide
torch is consid-
ered
satisfactory in
most
cases, but for
more
accurate testing,
we recommend
the
use
of a Dielectric
Differential Leak
De-
tector.
This
transistorized
model reduces
the
guesswork
in leak
testing
because it is
more
sensitive,
faster responding,
and
capable
of detecting
a
leak
even
though
the
surrounding
air is
contaminated.
The
leak
gun provides
an audible indication
of
a
refrigerant
leak.
3-7