25
moreover ,the gas flowing sound is intermittent and obviously louder .
Remedy
After shut down for several minutes ,open the tubing ,evacuate it and
then recharge the system with refrigerant .
4) Low efficiency
of compressor
Analysis of Trouble
Low efficiency
of
a
refrigerating
compressor
refers
to
the actual
reduction
of
gas
discharge
capacity
,and
hence
the
corresponding
reduction
of
refrigerating capacity
,under the
condition
that the
refrigerant in
the system
is
unchanged
.This
phenomenon
occurs
mostly
when the
compressor
has
been
used
for
quite
a
long
time
,its
moving
parts have
worn to a
considerable
degree
,fit
clearance
between
various
parts have
increased
and
sealing
property
of
its
gas
valve
has
deteriorated
,resulting
in an decrease in its actual gas
discharge capacity .
Methods of Judgment
Measure
the
high
and
low
pressures
with
pressure
gauges to see
whether they are normal .If an abnormal sound comes from the
compressor
or the temperature
of
its
causing
is
too
high
,Cut
the
discharge
port open
and operate
the compressor
,feel
it
if
there
is pressure
at the
discharge port
with your
finger
(For
a
normal
compressor
,its
discharge
port
is
difficult to
be blocked with
your finger if
you just apply a little effort).
5) Refrigerating oil left in evaporator tubing
Analysis of Trouble
During the process of refrigerating cycles ,a little refrigerating oil may
remain in the evaporator tubing ,and after a longer time of operation ,if
there is considerable refrigerating oil left in the evaporator ,the heat
conduction effect will be severely affected ,thus causing a poor refrigerating
effect .
Remedy
It is quite difficult to determine whether this trouble is caused by the
refrigerating oil left in the evaporator tubing ,because this kind of
phenomenon and other several trouble are tends to be confused .Generally
speaking ,you can make a judgment based on the frost formed on the
evaporator .If the frost does not cover the evaporator , and moreover ,it is
loosely formed ,you can make a judgment that the deterioration of
refrigerating
effect
is
due
to
the
accumulation
of
refrigerating
oil
left in the
evaporator
tubing
in
case
no
other
troubles
have
been
found
.
To
clear off
refrigerating
oil
left
in
the
evaporator
,dismantle
the
evaporator
,purge it
thoroughly
and
then
dry
it
.In
case
it
is
difficult
to
dismantle
it
,charge
refrigerant
from
the
evaporator
inlet
to
wash
it
several
times
,then purge
and dry it
with nitrogen .
Содержание HRB-271
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