accumulates there, the whole filter screen may be blocked totally, making
the refrigerant unable to go through. Clogging with dirt exhibits the same
symptoms as that with ice, namely, higher gas suction pressure, lower
temperature of discharged gas, and no gas flowing sound from the
evaporator. The difference between the both is as follows: if the clogging is
caused by
dirt
,
tapping
the
suspicious
clogged
point
(generally in the
capillary
or
the
connection
joint
of
the
filter)
may
cause
the
refrigerant to
flow through
partially,
resulting
in
some
corresponding
change,
whereas in
that case
if
you
heat
it
with
a
hot
towel,
no
reaction
will
happen,
no flowing
sound can
be
heard,
moreover,
there
is
no
periodic
change.
After
rejecting
the possibility
of
ice
clogging,
it
can
be
generally
considered
as the
clogging
due to dirt .
Remedy
Dismantle the
system,
remove the
dry
filter from
it,
purge the tubing with
nitrogen,
install
a
new
filter,
then
evacuate
it
and
finally
charge it with
refrigerant.
C) Clogging in filter
Analysis of Trouble
Total
clogging
of
a
filter
is
rarely
to
occur.
This
trouble
is
mostly
caused
by the paste-like
matter
formed
from
the
substances
filled
into
the system
or other
dust
after
the
refrigerator
has
been
used
for
a
longer
time, or by
the dirt accumulated
gradually
inside
the
filter.
Sometimes,
tapping
the filter
nay cause
a
passage
for
flowing,
Touching
it
with
your
hand,
you
will feel
that it is
cooler compared with its temperature in the normal state.
Remedy
The same
as described in the capillary clogging with dirt.
3) Troubles of Compressor
a) Breakage of gas
suction and discharge
valve blocks
Analysis of Trouble
The compressor
works
by
means
of
the
opening
and
closing of gas
suction valve
and
discharge
valve
to
suck
and
discharge
the
refrigerant. If
the valve
block
is
broken,
the
refrigerant
can
not
be
discharged,
and hence
no refrigerating can be achieved.
Method for making judgement
It is quite
difficult
to
differentiate
this
trouble
from
others
because they
often have
similar
symptoms.
In
repairing,
firstly,
hear
attentively
if
there is
some abnormal
sound
coming
from
the
compressor
(sometimes , the
broken pieces
of
valve
block
may
strike
against
the
cylinder),
and
feel the
compressor
casing
with
your
hand
to
ascertain
whether
it
is
too
hot, this is
also helpful to the troubleshooting; secondly, measure the pressures at the
high and low pressure ports of the compressor with pressure gauges, if the
gas suction valve block is broken, the suction pressure gauge pointer will
swing violently and the suction pressure is very high, whereas when the
gas discharge valve block is broken , the discharge pressure gauge pointer
28
Summary of Contents for HRB-271
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