Thor Kitchen TWC2403DI User manual

Wine Cooler
Service Manual
Models: TWC2403DI
Features
Energy efficiency
Micro foam technology
Low noise operation
Thick insulation for enerqv efficiency
Version number: 00.00
Edition: 2019-5-20

1
CONTENT
1. Content ................................................................ 2
2. Specifications ...................................................................... 3
3. Safety precautions .............................................................. 4
4. Function Schedule ................................................................. 7
5. System Flow Chart .............................................................. 8
6. Circuit Diagram .................................................................... 9
7. Maintenance Service and Trouble Shooting ..............10
8.List of Parts...............................................................28
2

Specifications
Models
Net capacity
(L) 458
Color Black
Power Supply
(V/Hz) 110-/60
Rated Input Power
(W) 370
Power Consumption
(kW.-h/24h) 1.3
Net Weight
(Lbs)264
Gross Weight
(Lbs)286
Unit Dimension 60*68.5*187
(W*D*H)(CM)
Packing Dimension
(W*D*H)(CM) 66*74*200
Container Quantity 40'HC (PCS) 54
3

Function Page
Function Schedule
• Energy efficiency
• Micro foam technology
• Low noise operation
• Thick insulation for energy efficiency
7

System Flow Chart
1. Schematic diagram of System Flow Chart
2. Brief Description of System Flow Chart
Model TWC2403DI is a fan cooling double-system wine
cooler. When the wine cooler is just powered on, the
refrigerant flows in the sequence:
Compressor-Condenser-Drier-Capillary
Restrictor-Evaporator.
8

Circuit Diagram
1. Schematic Circuit Diagram
2.Brief Description of Control Principle
Model TWC2403DI is the direct cooling double-system
Wine Cooler; an electronic type of all the control is
generally adopted. The display control PCB directly
controls the start and stop of compressor, and hence the
refrigerator temperature.
9

Maintenance Service and Trouble Shooting
5 Normal Phenomena—Not Troubles for Refrigerators
In a domestic refrigerator, there is not only a complicated electric control system, but
also a refrigerating system that is difficult to discern whether it is in a good working
condition. Both the systems are related and affect each other. If a certain part of a
refrigerator works abnormally .Its refrigerating efficiency will decrease .operation
properties will become unstable, or even it cannot be used normally for those serious
cases.
Refrigerators are generally of larger volume, once troubles appear, to send them to a
service department is really a tough thing, if such is the case, the user will always be in
suspense. Sometimes, normal phenomena will be erroneously regarded as troubles.
Therefore, before we deal with the topics of frequently occurring troubles of
refrigerators and their remedies ,we should firstly give a brief account of some normal
phenomena which are not troubles .In case any one of such phenomena occurs ,there
is no need to worry about it ,and the user can use it at total ease .
1).When the compressor of a refrigerator has just stopped running ,a rumbling sound
can be heard from inside its evaporator .This is a sound caused by the flowing of
refrigerant in the evaporator tubing .Because the pressure difference is still greater
after the compressor has just stopped running ,the refrigerant will flow for a certain
time , therefore ,this sound is a normal phenomenon.
2).A click sound can often be heard from the refrigerator .This is a normal sound
produced by the pull-in or release of the armature of a current deadweight start relay
when starting the compressor The compressor motor will produce a slight and uniform
sound while it is running .This sound is not easy to be heard in the daytime ,but of
course it can be heard distinctly at night.
3).The compressor consists of an electric motor and a compressing apparatus .During
its normal operation ,the motor's stator core and windings will rise to a temperature in
the range of 100℃~130℃,and the temperature of the piston and cylinder of the
compressing mechanism can also reach as above 100℃due to the heat produced
when compressing refrigerant .Most of the heat radiates to the air through the
compressor casing .therefore ,its casing is generally at a temperature between 78℃
~95℃,it is very hot .particularly in summer when the ambient temperature is higher .All
these are normal phenomena .•
4).For the direct cooling refrigerator ,a kind of irregular crack sound can be often heard
when the compressor is running for a certain period of time or has just stopped its
running .This sound is caused by the stress relief due to expansion and contraction
when temperature changes ,and will not
affect the normal application of refrigerator.
6 Common Troubles in Refrigerators and Their Remedies
Causes for troubles occurring in refrigerators are closely related to the quality of
components and workmanship in assembling by manufacturers as whether
refrigerators are properly used and maintained .The parameters generally used to
express the working conditions of a refrigerator include the temperature inside the
refrigerator .operation rate ,electric power consumption ,noise level ,and other
14

Maintenance Service and Trouble Shooting
functional indexes .If any one of these parameters is beyond its permissible range .this
indicates that there is a fault or trouble in the refrigerator.
During the whole service life of a refrigerator ,the probability of troubles occurring within
a union time is called its failure rate .Making a comparison between the control circuit
system of a refrigerator and its refrigerating system ,we can find that the failure rate of
the former is higher ,and that of the thermostat is the highest. In troubleshooting ,the
first thing you must do is to determine where the trouble comes from —the control
system or the refrigerating system .There is general no trouble indicating instrument
mounted on the domestic refrigerator .locations and natures of troubles should be
determined according to their respective features .therefore .experience in servicing is
very important to troubleshooting .Service technicians with rich experience can correctly
locate them and take reasonable remedy measures based on their comprehensive
analysis of trouble characteristics as well as operating conditions for various kinds of
refrigerators .
Three Essentials for Checkup
1) Look
a)Check the tubing of refrigerating system for cracks and various welding points for
leaks ;if leakage occurs ,an oil stain can be seen definitely .
b) Check the suction and exhaust pressure values (high pressure and low pressure) of
compressor to see whether they are normal.
c) Check the conditions of frost attached to its evaporator and gas return tube .It is
abnormal if frost has formed on part of the evaporator or there is no frost attached to it.
d) Pay attention to the speed of temperature drop inside wine storage compartment .It
is abnormal if the speed of temperature drop is obviously slower than the
corresponding normal speed.
e) Check the environment to see whether it is suitable for placing a wine cooler.
f) Check the door seal, case, and table surface and heat insulation layer.
g) Look at the main control board to ascertain if various indication states are normal.
2) Listen
a) Listen to the noises produced when the compressor is running
Hums from a fully enclosed aggregate unit is the sound caused by overload indicating
that the motor cannot be started normally. meanwhile ,a clattering sound can be heard
from inside the start relay ,which is produced because the start contacts cannot be
released normally .A whistling sound is caused by the high pressure gas flowing out of
the crack of the pressure tube inside the compressor ,and clucks are the sound of
striking after the suspended spring inside the compressor has broken .
During the normal operation of compressor, a slight and uniform hum sound due to
15

Maintenance Service and Trouble Shooting
Undulation of electric current can be heard generally ,this is a normal
phenomenon .However ,if it sounds like "tong ,tong ...",i.e., an impact sound inside the
Compressor, this means that a large quantity of wet vapour of refrigerant or
refrigerating oil has come into the compressor cylinder; if it sounds like "dang ,dang...",
a striking sound of metal parts inside the compressor ,this means that some moving
parts have loosened (note to differentiate this sound from those formed during starting
or stopping the compressor).
b) Listen to the sound caused by the flowing of gas in the evaporator
Open the refrigerator door while the compressor is in operation .incline your ear and
listen attentively the gas flow sound inside the evaporator .If it sounds like gentle
whistling accompanied by a sound similar to water flowing ,this is the sound produced
by the normal circulation of refrigerant within the evaporator .In case only the gas
flowing sound can be heard and there is no water flowing sound ,this indicates that the
refrigerant has already percolated .If neither the flowing sound nor the gas sounds from
the evaporator can be heard ,this means that the filter or capillary has been clogged .
3)Touch and Feel
a) Feel the compressor when running ,its temperature should be generally less than
95℃in the normal state (it may exceed 95℃in case of running for a longer period of
time ).
b) After the compressor has operated normally for 5-10 minutes, Touch and feel the
condenser ,the temperature of its upper part should be higher than that of its lower part
(or its right part is hotter than its left part .depending on the type of condenser coil ),this
indicates that the refrigerant is circulating . If the condenser is not hot ,this means the
leakage of refrigerant .In case the condenser radiates heat for only several minutes
and then cools down ,this means that the filter and capillary have been clogged .As for
the forced air cooling condenser ,hot air will be blown out of it ;this means that the
system is out of order.
c) Feel the filter's temperature During the normal operation of refrigerating system, the
temperature on the filter's surface should be a little higher than the ambient
temperature; if you touch it with your hand ,you will have a sense of slight heat .In
case dew condensation appears due to the fact that its temperature is obviously lower
than the ambient temperature .this means that most meshes of its screen has been
clogged .resulting in an obstructed flowing of refrigerant .thus causing a drop in
temperature due to throttling .
d) Feel the temperature of exhaust gas from the refrigerating system .the exhaust gas
should be very hot and this is the normal working state .For those refrigerator with
enclosed type of compressor refrigerating system, no frost or dew drop will from on the
gas suction tube .otherwise, there is something wrong in the system (Frosting and dew
condensation may appear for a very short time period when just starting the
machine .this is a normal phenomenon ).
16

Maintenance Service and Trouble Shooting
Because a wine cooler is a combination of several components .they are related and
have influence on each other .In case an abnormal phenomenon has been found
through the above-mentioned checkups ,you need not to make a hasty conclusion
based on only one abnormal phenomenon .It is advisable to find out two or more
abnormal phenomenon ,or conduct troubleshooting comprehensively with the aid of
instruments or other ways .because several kinds of troubles may share a common
abnormal phenomenon ,and two or more abnormal phenomena may occur
simultaneously due to a certain trouble .With this method ,you can reject some
suspicious troubles and finally make a correct judgment.
7 Analysis of Troubles and Troubleshooting
A. Poor Refrigerating Effect
The so-called "poor refrigerating effect " refers to the fact that the refrigerator can
operate and refrigerator normally .but the temperature in the wine cooler cannot drop to
the prescribed value under the stipulated working conditions .In view of there are many
causes for this phenomenon ,we are going to discuss and analyze it in the following 7
aspects :
1) Leakage of refrigerant
Analysis of Trouble
The leakage of refrigerant in the system will result in an insufficient refrigerating
capacity .the resulting phenomena are its lower gas suction pressure and exhaust
pressure as well as higher exhaust gas temperature .The exhaust tube feels rather
hot ,and a continuous gas flowing sound louder than usual can be heard at the outlet of
the capillary ,and no frost or a smaller quantity of loose frost appears on the
evaporator .After shut down .the balance pressure in the system is usually lower than
the saturation pressure corresponding to the same ambient temperature .
Remedy
In case there is leakage of refrigerant from the system ,do not hurry to recharge it with
refrigerant,manage to find out leak points immediately ,and make a note of from where
it leaks —welding points and parts .After having them repaired ,recharge refrigerant.
There are so many joints and sealed surfaces in a refrigerator .accordingly ,quite a lot
potential leak points do exist in the system .In troubleshooting ,pay attention to those
parts that are liable to leak ,check main connection points for oil seepage and tubing for
cracks .If there is no severer leak point ,charge the system with nitrogen and detect
leak points with the commonly adopted method , repair them .evacuate ,charge the
system with refrigerant ,and then turn on the wine cooler to make a test run .
2) Too much refrigerant charged into the system
Analysis of Trouble
a) In case the amount of refrigerant charged into the system exceeds its nominal
capacity ,the superfluous refrigerant will of course take some space of the
evaporator .thus reducing its heat-dissipation area and hence the refrigerating
efficiency of the system .The abnormal phenomena caused by this reason
are as follows :the gas suction and exhaust pressures are generally higher than
their respective normal values ,the temperature of its condenser is higher and the
electric current of the compressor rises , loose frost forms on the evaporator ,the
refrigerator temperature drops slowly ,and frost appears on the gas return tube .
17

Maintenance Service and Trouble Shooting
b) In case excessive refrigerant has been charged the liquid refrigerant that cannot
evaporates in the evaporator will return to the compressor, and thus a phenomenon of
"liquid striking" will occur The liquid refrigerant evaporates and effervesces as soon as
it flows into the refrigerating oil at the bottom of compressor. If the condition is severe,
foams will fill all over inside the compressor housing and be sucked by the piston.
causing damage to the components of compressor.
Remedy
According to the operating procedures ,it is mandatory to turn the machine off ,and
several minutes later ,open the refrigerant charging tube and let the refrigerant escape
from it .replace the dry filter ,recharge refrigerant after evacuating ,and then seal the
charging port.
3) There is air left in the refrigerating system
Analysis of Trouble
Residual air in the refrigerating system will reduce its refrigerating efficiency .The
prominent phenomena are the increase in its gas suction and exhaust pressures
(however, the gas exhaust pressure will not exceed its rated value ),obvious increase
in temperature in the segment from the compressor outlet to the condenser
inlet .Because there is air in the system ,both the gas exhaust pressure and
temperature will rise ,and 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)Too thick frost layer formed on evaporator
Analysis of Trouble
If a direct cooling refrigerator is to be used for a prolonged period of time, be sure to
defrost its evaporator regularly ;if you fail to do so ,the frost layer on the evaporator
tubing will become thicker and thicker .Heat conduction will be severely affected when
the whole tubing is wrapped with a transparent ice layer ,and finally the temperature in
the refrigerator cannot drop down to the prescribed range .
18

Maintenance Service and Trouble Shooting
Remedy
Turn the refrigerator off, and make preparations for defrosting ,open the wine cooler
glass door to let the air come in ,or use a fan to speed up air flowing so as to shorten
the time needed for defrosting .Never strike the frost layer with any iron tools or wood
stick in order to avoid damage to the evaporator tubing .
6) 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.
7) Flowing obstructed in refrigerating system
Analysis of Trouble
Because the refrigerating system was originally not purged thoroughly, some of the
filter screen meshes have been clogged by dirt accumulated in the filter after using it
for a certain time of period. Thus resulting in a decrease in flow rate, and hence a
poorer refrigerating effect.
The abnormal phenomena caused by this kind of slight clogging in the system are as
follows: the gas discharge pressure is lower .the temperature of discharged gas drops
down .the position clogged has a temperature lower than that in normal conditions, and
for a severe clogging, even dew condensation as frosting may appear.
Remedy
Purge the tubing, and after replacing the dry filter with a new one or clearing it
thoroughly, recharge the system with refrigerant and seal the charging port.
B. No Refrigerating
The phenomenon that the compressor runs normally. but no frost (or only a little frost )
appears on the evaporator ,and the refrigerator temperature does not drop down is
called "no refrigerating". There are many causes for this trouble and it is relatively
complicated, in servicing. Special attention to finding direct causes for this
phenomenon. Three main potential causes for this trouble are analyzed below:
1) All refrigerant in the system has leaked out
19

Maintenance Service and Trouble Shooting
Analysis of Trouble
Leak points in the refrigerating system have not been found and repaired timely. thus
resulting in the total escape of refrigerant .There are two kinds of leakage :
l) Slow leakage
For instance, when we want to use a refrigerator that has been put out of quite a long
time, we find the leakage of refrigerant ,or in the course of its operation ,we have found
that the refrigerator is gradually becoming not so cold and finally no refrigerating cab be
achieved ;
ii) Fast leakage
In that case .all the refrigerant will escape swiftly due to abrupt rupture of system tubing.
Symptoms of total leakage of refrigerant are mainly as follows: the compressor can be
started easily (if there is no damage to the compressor parts) and its operating current
becomes low .its gas suction pressure is high and discharge pressure is lower .the gas
discharge tube feels rather cold, no sound of gas eruption from the liquid in the
evaporator can be heard, and no will gush out of the process tube if you cut it open
after shutdown .
Remedy
Check the whole machine, particularly those locations which are liable to leak .After
leak points have been found ,repair them or replace them with new parts according to
specific circumstances .then evacuate the system and finally charge refrigerant.
2) Refrigerating system has been clogged
a) Clogged with Ice
Analysis of Trouble
The dryness treatment for the major parts in the refrigerating system has been
performed improperly, the effect of air purging for the whole system is not good, or the
water content in the refrigerant is out of standard, all these will cause the expansion
valve to be clogged with ice The symptom for this trouble are as follows: the
refrigerator sometimes can refrigerate and sometimes cannot :the refrigerator
compartment works normally at the beginning ,but after working for a certain period of
time ,frosting begins at the clogged position .evaporation temperature reaches below
0DC, water will accumulate at the narrow part of the capillary and clog it gradually .then
frost begins to melt at the evaporator ,no gas flowing sound can be heard .and the gas
suction pressure assumes a state of vacuum .Note that these phenomena will appear
intermittently ; sometimes .the refrigerator works well .and sometimes not well .In order
to determine whether it is clogged with ice .heat the suspicious points with hot water to
make ice melt .and after a while if a gas flowing sound resulting from an abrupt gush is
heard and the gas suction pressure rises as well ,it can be confirmed that the trouble is
caused by ice clogging .
Remedy
If there is too much moisture in the refrigerating system, it is advisable to release the
refrigerant, purge the tubing with nitrogen, and then charge the system with the filtered
refrigerant. However, the commonly adopted method is to connect a filter with moisture
absorbers (such as silica-gel, anhydrous calcium chloride) to the refrigerating system
so as to filter out the moisture from the system, then replace the filter, evacuate it again
and finally charge the system with refrigerant.
20

Maintenance Service and Trouble Shooting
b) Clogged with dirt in capillary
Analysis of Trouble
The capillary inlet is a place where coarse-grained dirt or refrigerant oil in the system
will tend to settle down and clog it. In case considerable dirt 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 cannot be discharged, and hence no refrigerating can be achieved.
Method for making judgment
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 will swing drastically and the
discharge pressure is very high. In the both cases, stop the compressor at once, and if
technique is available, open the cylinder cover and check up the valve block, repair it,
or replace it with a new one, 21