26
6) Following obstructed in refrigerating system
Analysis of Trouble
Because
the
refrigerating
system
was
originally
not
purged
thoroughly ,some of the filter screen meshes have been clogged by dirt
accumulated in the filter after using it for a certain time of period ,thus
resulting in a decrease in flow rate ,and hence a poor refrigerating effect .
The abnormal
phenomena
caused
by
this
kind
of
slight
clogging in the
system are
as
follows:
the
gas
discharge
pressure
is
lower ,the
temperature
of
discharged
gas
drops
down
,the
position
clogged has a
temperature
lower
than
that
in
normal
conditions
,and
for
a severe
clogging ,even dew condensation as frosting may appear .
Remedy
Purge
the
tubing
,and
after
replacing
the
dry
filter
with
a
new one or
clearing it
thoroughly
,recharge
the
system
with
refrigerant
and
seal the
charging port .
B.
No Refrigerating
The phenomenon
that
the
compressor
runs
normally
,but
no
frost (or
only a little
frost
)
appears
on
the
evaporator
,and
the
refrigerator
temperature
does
not
drop
down
is
called "no
refrigerating$.
There are
many causes
for
this
trouble
and
it
is
relatively
complicated
,
too . In
servicing
,special
attention
to
finding
direct
causes
for
this
phenomenon
.Three
main
potential
causes
for
this
trouble
are
analyzed
below :
1) All refrigerant in the
system has leaked out
Analysis of Trouble
Leak
points
in
the
refrigerating
system
have
not
been
found and
repaired
timely
,thus
resulting
in
the
total
escape
of
refrigerant
.There are
two kinds of leakage :I)
slow leakage
for instance ,when we want to use a
refrigerator that has been put out of quite a long time ,we find the leakage
of refrigerant ,or in the course of its operation ,we have found that the
refrigerator is gradually becoming not so cold and finally no refrigerating
cab be achieved ; ii)
fast leakage
in that
case ,all the refrigerant will
escape swiftly due to abrupt rupture of system tubing .
Symptoms of total leakage of refrigerant are mainly as follows : the
compressor can be started easily (if there is no damage to the compressor
parts) and its operating current becomes low ,its gas suction pressure is
high and discharge pressure is lower ,the gas discharge tube feels rather
cold ,no sound of gas eruption from the liquid in the evaporator can be
heard ,and
no
will
gush
out
of
the
process
tube
if
you
cut
it
open after
shutdown .
Summary of Contents for HRB-271
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