Adjustments; Compressor; Ptc-Starter - LG LTN16385PL Service Manual

4. ADJUSTMENTS

4-1 COMPRESSOR

4-1-1 Function.
The compressor sucks evaporated gas in low pressure and
lowers the temperature form the evaporator or fridge and
compress this gas at high temperature and high pressure
and passes it on to the condenser.
4-1-2 Composition.
Compressor is made up of a system that compresses the
gas, the motor of the compressor and the cover that protects
the device. On the exterior of the compressor is found the
PTC (thermistor) and the OLP (overload protector).
Treat and repair in carefully, because it contains components
of processing accuracy of 1/1000 mm and is sealed dust or
moisture after manufacture.
4-1-3 Notes for use.
(1) Protect your refrigerator of an over voltage or over
current.
(2) Do not hit:
If is forced or hit (dropping or careless treatment), Noise can
originate or have an inefficient operation.
(3) Use appropriate electrical components for the
compressor.
(4) Note for storing the compressor: If the compressor gets
wet during rain and oxidized in the hermetic terminal, may
have a poor operation and cause poor contact.
(5) Ensure that dust, moisture and soldering flux are not
introduced to the compressor during its replacement. Dust,
moisture or flux are introduced to the pipe can cause noise or
clog it.
4-2 PTC STARTER
4-2-1 PTC Composition
(1) The PTC (thermistor) is a semiconductor component that
uses starting ceramic material which is composed of
BaTiO 3.
(2) The higher the temperature, the greater the resistance
value. These characteristics are used for engine starting.
4-2-2 PTC Function
(1) The PTC is attached to the hermetic compressor and is
used for starting the refrigerator compressor.
(2) The compressor of a household refrigerator, uses a motor
of an induction phase, the normal engine operation is started
at the time of starting, the current flows through the auxiliary
winding. Once the boot is completed, the current is cut in the
auxiliary winding because the PTC is connected in series
and this increases its resistance. The characteristics of the
PTC have the above functions. Then, the PTC is used as an
engine starting system.
4-2-3 PTC- Circuit Diagram Applied.
• According to starting motor method.
OLP (OVERLOADED PROTECTOR)
PTC
5
3
PTC STARTER
RSIR
4-2-4 Restarting the engine and cooling of the PTC
(1) For the restart after power failure during normal operation
of the compressor motor, connect the power cord after 5
minutes for the pressure of the refrigeration cycle to stabilize
and cool the PTC.
(2) During normal operation of the compressor motor, the
elements of PTC generate heat continuously. Hence, if the
PTC is not cooled at some time after power failure, the
engine could not operate again.
4-2-5 Relation between the PTC and OLP
(1) If your power goes out during operation of the
compressor and is reestablished before the PTC has cooled,
(off in a span of 2 minutes or reconnect the power cord due
to a bad connection), the PTC cooling is reached and the
resistance value increases. As a result, the current cannot
flow to the auxiliary winding and the motor cannot start,
because the OLP operates on current flow through the main
winding.
(3) While the OLP repeat the operation on and off about 3 to
5 times, the PTC cools the compressor and the engine
operates normally. If the OLP does not operate when the
PTC is hot compressor motor will overheat causing a short
circuit or even fire. Then, use a flawless OLP.
4-2-6 Note for Using the PTC-Starter
(1) Be careful not to allow over-voltage and over-current.
(2) Do not drop or handle carelessly.
(3) Keep away from any liquid. If liquid such as oil or water
enters the PTC, PTC materials may fail due to breakdown of
their insulating capabilities.
(4) Do not change the PTC at your own convenience. Do not
disassemble the PTC or the mold. Damage to the exterior of
the PTC, the resistance value is altered and can cause
failures on the compressor motor. Use a PTC in good
conditions.
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COMPRESSOR
M
S
M
S
6
HERMETIC
TERMINAL
Figure 20