Adjustment; Compressor; Ptc-Starter - LG LRBP1031W Service Manual

ADJUSTMENT

1 COMPRESSOR

1) Role
The compressor intakes low temperature and low pressure
gas evaporated from evaporator of the refrigerator, and
condenses this gas to high temperature and high pressure
gas, and then plays delivering role to Condenser.
2) Composition
The Compressor is composed of compressor
apparatus compressing gas, compressor motor
moving compressor apparatus, and case protecting
compressor apparatus and motor. There are PTC-
Starter, and Over Load Protector (OLP) in the
Compressor outside. On the other hand, because the
Compressor consists of 1/1000mm processing
precision components and is sealed after production
in absence of dust or humidity, deal and repair with
care.
3) Note for Usage
(1) Be careful not to allow over-voltage and over-current.
(2) Do no strike.
If applying forcible power or strike (dropping or careless
dealing), poor operation and noise may occur.
(3) Use proper electric components appropriate to the
compressor.
(4) Note to Keep Compressor dry.
If compressor gets wet in the rain and rusts in the pin of
hermetic terminal, the result may be poor operation
from poor contact.
(5) Be careful that dust, humidity, and welding flux don't
flow in the compressor inside in replacing the
compressor. Dust, humidity, and flux due to welding
which inflows to cylinder may cause lockage and noise.

2 PTC-STARTER

1) Composition of PTC-Starter
(1) PTC (Positive Temperature Coefficient) is a no-contact
semiconductor starting device which uses ceramic
material. This material consists of BaTiO
(2) The higher the temperature is, the higher becomes the
resistance value. These features are used as the
starting device for the Motor.
2) Role of PTC-Starter
(1) PTC is attached to hermetic compressor used for
refrigerator, show case and starts motor.
(2) Compressor for household refrigerator applies to
single-phase induction Motor.
For normal operation of the single-phase induction
motor, in the starting operation current flows in both
main coil and sub-coil. After the starting is over, the
current in subcoil is cut off. The proper features of PTC
play all the above roles. So, PTC is used as a motor
starting device.
3) PTC-Applied Circuit Diagram
According to Starting Method for the Motor
OVERLOAD PROTECTOR(O.L.P)
4) Motor Restarting and PTC Cooling
(1) For restarting after power off during normal compressor
(2) During normal operation of the Compressor Motor, PTC
5) Relation of PTC-Starter and OLP
(1) If the power is off during operation of compressor and
(2) While the OLP repeats on and off operation about 3-5
.
3
6) Note to Use PTC-Starter
(1) Be careful not to allow over-voltage and over-current.
(2) Do no strike.
(3) Keep apart from any liquid.
(4) Don't change PTC at your convenience.
(5) Use a properly repaired PTC.
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PTC
5
3
PTC STARTER
RSIR
motor operation, plug the power cord after 5 min. for
pressure balance of refrigerating cycle and PTC
cooling.
elements generate heat continuously. Therefore,
if PTC isn't cooled for a while after the power has been
shut off, the motor can't operate again.
the power is on before the PTC is cooled, (instant shut-
off within 2 min. or reconnect a power plug due to
misconnecting), the PTC isn't cooled and a resistance
value grows. As a result, current can't flow to the sub-
coil and the motor can't operate and the OLP operates
by flowing over current in only in the main-coil.
times, PTC is cooled and compressor motor performs
normal operation.
If OLP doesn't operate when PTC is not cooled,
compressor motor is worn away and causes a short
curcuit and fire. Therefore, use a properly fixed OLP
without fail.
Don't apply a forcible power or strike.
If liquid such as oil or water enters the PTC,
PTC materials may break due to insulation breakdown
of the material itself.
Don't disassemble PTC and mold. If the exterior of the
PTC-starter is damaged, resistance value is altered and
it may cause poor starting of the compressor motor.
C
COMPRESSOR
MOTOR
M
S
M
S
6
HERMETIC
TERMINAL
Figure 19