31
In case the compressor cannot be started, this will generally exhibit in
the power supply circuit, for instance, power failure, poor contact of switch,
and blown fuse. Make a comprehensive analysis of these phenomena, fine
out its real cause and take correct measures to remove this trouble.
Remedy
a) Check
the
input
power
circuit
to
see
whether
where
is
voltage of the
power supply,
namely,
the
circuit
which
is
connected
to
the
knife
switch.
This can
be
determined
with an
avometer
or
a
test
pencil.
If
a
blown fuse is
found, ascertain
and
remove
its
cause,
then
replace
it
with
a
new one of
the same specifications.
b) Check
the
compressor
accessories,
including
its
thermal
protector
and relay.
In
case
the
thermal
protector
is
damaged,
the
compressor
cannot be
powered on.
If the
relay
is
out
of
order, the motor
will
not run and
hum sound
can
be
heard
from
it
after
the
compressor
is
turned
on, in that
case, shut
it
down
immediately,
otherwise,
the
motor
windings
will be
burned out in case this
condition lasts longer.
c) Check
the
relay
contacts
and
plugs
to
see
if
they
are
perfect and
work reliably. Poor contact may
cause the motor not running or humming.
2) Check the circuit voltage to
see whether it is normal.
Analysis of trouble
If the
circuit
voltage
is
obviously
lower
than
its
rated
value,
it
will be
difficult to start the motor, and a hum sound can be heard from it.
Remedy
Measure
the
voltage
with
a
voltmeter,
if
it
is
really
too
low, give
directions
to
the
user
for
buying
a
stabilizer
so
as
to
step
up
the
voltage,
thus normal operation can
be achieved.
3) Check the thermal relay to see whether its contacts
are
closed.
Analysis
of Trouble
The
contacts
of
thermal
relay
sometimes
may
be
open
due to the
leakage
of temperature sensing
agent from the temperature sensor.
Remedy
Remove
the
relay
cover
to
check
up
its
contacts,
if
they
are
open, this
means
that
the
original
setting
is
not
properly
set
or
temperature
sensing
agent has
leaked
out
of
the
temperature
sensor.
Try
to
turn
the
adjusting
stem of
this value
in
the
direction
of
the
lower
temperature graduation, then
check the
contacts
to
see
whether
they
are
closed.
If
they
are
still not
closed,
dismantle
the
temperature
sensing
disc
and
then
immerse it into
warm water
to
see
whether
the
contacts
actuate,
if
not,
it
can be
preliminarily
determine
that
temperature
sensing
agent
has
leaked
out, and
it must be replaced with a new thermostat.
4) Motor troubles and other electric faults
a) Motor windings have been burned or short-circuited between turns
Analysis of Trouble
When motor windings have been burned or short-circuited between
Summary of Contents for HRB-271
Page 15: ...CIRCUIT DIAGRAM 14 ...
Page 36: ...36 ...
Page 37: ...37 ...
Page 38: ...38 ...
Page 41: ......
