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Refrigerator
Service Manual
Model: WHS-185C1
Features
• Energy efficiency
• Micro foam technology
• Low noise operation
• Thick insulation for energy efficiency
• Latest No. 2 microbiological technology
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TABLE OF CONTENTS
TABLE OF CONTENTS
1.
Table of Contents .................................................................................... 1
2.
Product Code Illumination and Series Introduction ..................... 2
3.
Specifications ................................................................................ 3
4.
Safety Precautions .................................................................................. 4
5.
Function Schedule ................................................................................... 7
6.
System Flow Chart .................................................................................. 8
7.
Circuit Diagram .............................................................................. 9
8.
Maintenance Service and Troubleshooting .................................10
9.
Exploded View ............................................................................... 30
10.
List of Parts .................................................................................. 31
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Specifications
Specifications
Model
Capacity
(gal.)
WHS-185C1
37.5
Color
White
Power Supply
(V/Hz)
115V/60HZ
Rated Input
Power (W)
108
Power Consumption
(kWh/Y)
218
Net Weight
64
(lbs.)
Gross
Weight (lbs.)
Unit Dimension
(DxWxH)
(in.)
Packing Dimension
(DxWxH)
(in.)
Container Quantity
40HQ
(PCS)
70.5
29x21x33
30x21x35
194
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Safety Precautions
Safety Precautions
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Safety Precautions
5
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Safety Precautions
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Function Schedule
Function Schedule
• Energy efficient
• Micro foam technology
• Low noise operation
• Thick insulation for energy efficiency
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System Flow Chart
System Flow Chart
1. Schematic diagram of System Flow Chart
Flow sequence: 123451
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Circuit Diagram
1. Schematic Circuit Diagram
Circuit Diagram
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Maintenance Service and Troubleshooting
Maintenance Service and Troubleshooting
1. No cooling
No cooling
Does compressor
run after turning power
off for five minutes and
turning back on?
Check and repair according to
"The compressor does not
work" chart.
YES
Does compressor
run naturally and is
condenser cooling
too slowly?
YES
Blocked by ice or debris. Change
filter and refrigerant.
Refrigerant is leaking. Check
NO
and repair.
The correct amount of refrigerant should
!
be added to unit when recharging.
10
NO
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Maintenance Service and Troubleshooting
2. The compressor does not stop
Compressor does not
stop
Does the refrigerator
refrigerate?
NO
Check and repair according to the
"No cooling" chart.
YES
Is cooling capacity
insufficient?
NO
Check and repair according to the
"Cooling capacity is insuffi cient"
chart.
YES
1. Was the thermostat
set to the coldest setting?
2. Is the ambient temperature too high or
the refrigerator near a heat source?
3. Was the door opened too many
times or is there too much
food inside?
NO
Adjust and instruct owner
how to use.
YES
Check and repair the main control
panel.
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Maintenance Service and Troubleshooting
3. Cooling capacity is insufficient
Cooling capacity is
insufficient.
Is the ambient temperatur e
lower than 60.8°F?
YES
Is the thermostat correct?
NO
Is refrigerant leaking?
YES
NO
Adjust and instruct owner how
to use.
YES
Repair
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Maintenance Service and Troubleshooting
4. The compressor does not work
The compressor
does not work.
Does the refrigerator
light turn on when the
door is opened?
NO
Is appliance
connected to a
power source?
NO
Repair
YES
YES
Is the ambient
temperature lower than
60.8°F?
YES
YES
Is the thermostat
NO
correct?
Adjust and instruct
owner how to use.
Does the control
panel have a 220V
power output?
NO
Check and repair
the control panel.
YES
Does the compressor
have a 220V power
output?
NO
Check all power
cords.
YES
Check and repair
compressor & accessories.
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Maintenance Service and Troubleshooting
5. Normal Refrigerator Functions
A domestic refrigerator not only does it have a complicated electrical control
system, but also a refrigerating system that sometimes makes it difficult to figure
out if it is in good working condition. Both systems work in tandem and affect
each other. If one malfunctions, this can decrease efficiency or operation or even
lead to complete breakdown of the unit.
Since refrigerators are generally big, it’s not always practical to send them to
a service department over small issues. Sometimes these issues are normal and
not a sign of real malfunction. Therefore, before dealing with actual problems,
below is a brief account of some normal occurrences that might happen to the
unit. There is no need to worry; they can usually be fixed easily.
Normal Functions:
A. When the compressor has just stopped running, a rumbling sound can be
heard from inside the evaporator, which is caused by refrigerant flowing in
the evaporator tubing. Since the pressure difference is still greater after
the compressor has stopped running, the refrigerant will flow for some time,
so this sound is normal.
B. When the compressor starts running, a clicking sound can often be heard,
which is produced by the motion of deadweight start relay. The
compressor motor will produce a slight and uniform sound while it is
running. This sound is not easy to hear in the daytime, but it can be heard
at night.
C. The compressor consists of an electric motor and a compressing device.
During normal operation, the motor's stator core and windings will rise to a
temperature in the range of 212°F–230°F, and the temperature of the
piston and cylinder can reach as high as 212°F due to the heat produced
by the compressing refrigerant. Most of the heat escapes through the
compressor casing; therefore, its casing is generally at a temperature
between 185°F–194°F. It is extremely hot, particularly in summer when the
ambient temperature is higher.
D. For a direct cool refrigerator, an irregular cracking sound can often be
heard when the compressor is running for a prolonged period of time or
has just stopped running. This sound is caused by the tension from the
expansion and contraction when there is a temperature change, and it will
not affect the refrigerator’s normal operation.
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6. Common Problems in Refrigerators and Their Remedies
Issues occurring in refrigerators are closely related to the quality of their
components, the manufacturers’ workmanship, and if they are properly used and
maintained. The aspects generally used to gauge the working conditions of a
refrigerator include its temperature, operation rate, power consumption, noise
level, and other functional indexes. If any one of these factors is beyond its
permissible range, this indicates that there is a fault or issue in the refrigerator.
During the life cycle of a refrigerator, the probability of an issue occurring
within a specific time is called its failure rate. Comparing the refrigerator’s control
circuit system and its refrigerating system, the failure rate of the former is higher,
and that of the thermostat is the highest. In troubleshooting, first determine where
the problem originates from: the control system or the refrigerating system.
Generally there is no trouble-indicating instrument mounted on a domestic
refrigerator, so an issue’s location and nature should be determined according to
its features. Therefore, experience in servicing is important in troubleshooting.
Experienced service technicians can correctly locate issues and take reasonable
measures based on their comprehensive analysis of problematic characteristics
and of various kinds of refrigerators.
Three Checkup Essentials:
1. Look
a. Check the refrigerating system tubing for cracks and welded parts for
leaks. If there is a leakage, an oil stain will appear.
b. Check the suction and exhaust pressure values (high and low pressures)
of compressor to see if they are normal.
c. Check frost conditions on the evaporator and the gas return tube. It is
abnormal to see no frost or frost on only one part of the evaporator.
d. Check the speed of temperature drop inside freezer compartment. It is
abnormal if the speed is noticeably slower than the normal.
e. Check area to see if it is suitable for placing a refrigerator there.
f. Check door seal, casing, surface, and thermal insulation layer.
g. Look at the main control panel to determine if various indicators are
normal.
2. Listen
a. Listen to the noises emitted when the compressor is running. Hums from
a fully enclosed unit is caused by overload, indicating that the motor
cannot be started normally. A clattering sound from inside the start relay
signifies the start contacts cannot be released normally. A whistling
sound is caused by high-pressure gas escaping through a crack in the
pressure tube inside the compressor. The sound of striking clunks
indicate a suspended spring inside the compressor has broken.
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Maintenance Service and Troubleshooting
During compressor’s normal operation, a faint and constant hum due to
undulation of electrical current can be heard; this is normal. However, if it
sounds like an impact sound inside the compressor, this means that a
large quantity of wet saturated vapor of refrigerant or refrigerating oil has
entered the compressor cylinder. If it sounds like a striking sound of
metal parts inside the compressor, this means that some part has
become loose. (Be sure to differentiate this sound from those formed
during the compressor starting or stopping.)
b. Open the refrigerator door while compressor is in operation, and listen to
the sound of gas flow 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. If 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 sound can be heard, this means that the filter or
capillary is clogged.
3. Touch and Feel
a. After the compressor has operated normally for 5–10 minutes, 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 properly. If the condenser is not hot, this means the refrigerant
is leaking. If the condenser is hot for only a few minutes and then cools
down, this means that the filter and capillary are clogged. If the forced
air-cooling condenser has hot air blowing out, the system is out of order.
b. Feel the filter's temperature. During normal operation, the temperature on
the filter's surface should be a little higher than the ambient temperature.
If condensation appears, it is because the filter’s temperature is lower
than the ambient temperature and the screen is clogged. This obstructs
the flow of refrigerant, causing a drop in temperature due to throttling.
c. Feel the temperature of exhaust gas from the refrigeration system. The
exhaust gas should be extremely hot during normal operation. For
refrigerators with an enclosed compressor refrigeration system, there
should be no frost or condensation on the gas suction tube. Otherwise,
there is something wrong in the system. (It is normal for frost and
condensation to appear for a short period of time when starting the
machine.) Since a refrigerator is a combination of several components,
these elements are connected to and influence each other. If a problem
is discovered through any of the previously mentioned checkups, do not
make a hasty conclusion based on only one issue. It is advisable to
analyze and conduct troubleshooting comprehensively, with the aid of
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Maintenance Service and Troubleshooting
instruments or other ways, because several issues may share a common
source and several problems may occur simultaneously due to a specific
reason. With this method, some suspicious issues can be eliminated and
a correct judgment can be reached.
7. Analysis of Problems and Troubleshooting
A. Poor Refrigerating Effect
The so-called "poor refrigerating effect” refers to when the refrigerator
operates normally, but it does not cool down to the temperature indicated by the
thermostat. Possible causes for this occurrence are discussed and analyzed
below:
1. Refrigerant Leaks
Analysis of Problem
Refrigerant leakage will result in an insufficient refrigerating capacity, which
will lower the gas suction and exhaust pressures and increase the exhaust gas
temperature. The exhaust tube will be rather hot, and a continuous gas-flowing
sound from the outlet of the capillary will be louder than normal. Little to no frost
will appear on the evaporator. After shutting down, the balance pressure in the
system is lower than the saturation pressure corresponding to the ambient
temperature.
Solution
If there is a refrigerant leak, do not rush to recharge it with refrigerant. Since
there are many joints and sealed surfaces in a refrigerator, there are numerous
potential leak points. Therefore, locate the point(s) of leakage and note from
where it leaks. After repairing, recharge refrigerant. In troubleshooting, pay
attention to those parts that are prone to leak, checking main connection points
for oil seepage and tubing for cracks. If there is no severe leak, charge the
system with nitrogen to detect leak points. Once the leak is found, repair it, empty
the system, charge with refrigerant, and turn on the refrigerator for a test run.
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2. Too much refrigerant charged into the system
Analysis of Problem
a. If the amount of refrigerant charged into the system exceeds its capacity,
the surplus refrigerant will take space in the evaporator, which will reduce
its heat-dissipation area and the refrigerating efficiency. Malfunctions
caused by this abnormal occurrence are:
i. the gas suction and exhaust pressures are higher than normal,
ii. the condenser is hot,
iii. the compressor’s electric current rises,
iv. loose frost forms on the evaporator,
v. the refrigerator temperature drops slowly, and
vi. frost appears on the gas return tube.
b. If excessive refrigerant has been charged, the liquid refrigerant that
cannot evaporate in the evaporator will return to the compressor, causing
"liquid striking." The refrigerant evaporates and bubbles as soon as it
flows into the refrigerating oil at the bottom of compressor. In severe
cases, foam will cover the inside of the compressor and be pulled in by
the piston, causing damage to the components of the compressor.
Solution
According to operating procedures, it is necessary to turn the appliance off.
After a few minutes, open the refrigerant charging tube, let refrigerant escape,
replace dry filter, recharge refrigerant after evacuating, and seal charging port.
3. Air left in the refrigerating system
Analysis of Problem
Residual air in the refrigerating system will reduce its refrigerating efficiency.
The main effects are a higher temperature in the segment from the compressor
outlet to the condenser inlet and an increase in the gas suction and exhaust
pressures, although the gas exhaust pressure will not exceed its rated value.
Since there is air in the system, both the gas exhaust pressure and temperature
will rise, and the gas-flowing sound is intermittent and louder.
Solution
Turn off the refrigerator for several minutes, then open the tubing, evacuate it,
and recharge the system with refrigerant.
4. Low efficiency of compressor
Analysis of Problem
Low efficiency of a refrigerating compressor refers to the reduction of gas
discharge capacity and the corresponding reduction of refrigerating capacity
due to the fact that the refrigerant in the system is unchanged. This normally
occurs when the compressor has been in use for a long period of time: its
moving parts have worn out, clearance fits have increased, and the sealing
property of its gas valve has deteriorated, causing a decrease in its gas
discharge capacity.
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Maintenance Service and Troubleshooting
Solution
Measure the high and low pressures with pressure gauges to see if they are
normal. If an abnormal sound comes from the compressor or the temperature is
too high, cut the discharge port open and operate the compressor. With a finger,
feel if there is pressure at the discharge port. In a normal compressor, its
discharge port is difficult to block with a finger.
5. Thick frost layer on evaporator
Analysis of Problem
If a direct cool refrigerator will be used for a prolonged period of time, be sure
to defrost its evaporator regularly; otherwise, the frost layer on the evaporator
tubing will become thick. Heat conduction will be severely affected if the whole
tubing is covered in ice, and the temperature in the refrigerator will not be able to
drop to the ideal range.
Solution
To defrost, first turn refrigerator off. Next, open refrigerator door to let in air or
use a fan to speed up airflow and defrosting process. To avoid damaging the
evaporator tubing, never strike frost layer with any iron tools or wooden sticks.
6. Refrigerating oil in evaporator tubing
Analysis of Problem
During refrigerating cycles, refrigerating oil residue may remain in the
evaporator tubing. However, if there is a considerable amount of refrigerating oil
in the evaporator, the heat conduction effect will be severely affected, which will
cause poor refrigeration effect.
Solution
It is sometimes difficult to determine if this issue is caused by refrigerating oil
residue in the evaporator tubing because it tends to be confused with other
problems. Generally, the cause can be determined by examining the frost on the
evaporator. If there is little to no frost covering the evaporator, this means the
deterioration of refrigerating effect is due to the accumulation of refrigerating oil
residue in the evaporator tubing, unless another problem have been discovered.
To remove refrigerating oil residue in the evaporator, disassemble the evaporator,
purge it thoroughly, and dry it. If it is difficult to disassemble, charge refrigerant
from the evaporator inlet several times to wash it. Then, purge and dry it with
nitrogen.
7. Obstructed flow in refrigerating system
Analysis of Problem
If the refrigerating system is not cleaned thoroughly, some of the filter screen
meshes can become clogged with dirt that accumulated after a long period of
use. This causes a decrease in flow rate and a poor refrigerating effect.
Malfunctions caused by this abnormal occurrence are:
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Maintenance Service and Troubleshooting
a. decrease of gas discharge pressure,
b. lower temperature of discharged gas and of the clogged area, and,
c. in severe cases, condensation or frosting may appear.
Solution
Purge tubing and replace the dry filter with a new one or clean it thoroughly.
Recharge the system with refrigerant and seal the charging port.
B. No Refrigerating
When the compressor runs normally, but little to no frost appears on the
evaporator and the refrigerator temperature does not lower, this is termed "no
refrigerating." There are many causes for this problem, and it can be complicated
to determine. In servicing, special attention should be given to discover the cause
of the problem. Some common causes for this malfunction are analyzed below:
1. Entire refrigerant has leaked out
Analysis of Problem
If leak points in the refrigerating system have not been found and repaired in
a timely manner, this can result in the refrigerant completely leaking out. There
are two kinds of leakage:
a. Slow leakage: When a refrigerator has not been used in a long time, the
refrigerant might gradually leak out. If in the course of operating the
refrigerator it gradually becomes not as cold as normal and, eventually,
does not refrigerate, there is a slow leakage.
b. Fast leakage: All of the refrigerant escapes swiftly from a rupture in
system tubing.
Symptoms of total leakage of refrigerant are as follows:
a. the compressor can be easily started (if there is no damage to the
compressor parts),
b. the operating current decreases,
c. the gas suction pressure increases,
d. the discharge pressure decreases,
e. the gas discharge tube is cold,
f. no sound of gas flow in the evaporator can be heard, and
g. no gas escapes out of the process tube after cutting it open.
Solution
Check the whole appliance, particularly locations which are prone to leak.
After leak point(s) have been found, repair or replace with new parts, according
to specific circumstances, and then empty the system to recharge refrigerant.
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2. Refrigerating system is clogged with ice
Analysis of Problem
The expansion valve can become clogged with ice if the moisture is not
removed properly from refrigerant system, air purging is done improperly, or the
water content in the refrigerant is substandard. The symptoms for this condition
are:
a. irregular refrigeration, sometimes working normally at the beginning, but,
afterward, frost forms at the clogged area;
b. evaporation temperature drops below 32°F;
c. water accumulates at and clogs the narrow part of the capillary;
d. frost melts at the evaporator;
e. no sound of gas flowing can be heard; and
f. The gas suction pressure becomes a vacuum.
Note that these occurrences will appear intermittently; sometimes the
refrigerator works well and other times it does not. In order to determine if the
system is clogged with ice, heat suspicious points with hot water to melt any ice.
If the sound of gas flowing is heard and the gas suction pressure rises, then the
system was clogged with ice.
Solution
If there is too much moisture in the refrigeration system, release the
refrigerant, purge the tubing system with nitrogen, and recharge the system with
filtered refrigerant. Another method is to connect a filter with moisture absorbers,
such as silica gel or anhydrous calcium chloride, to the refrigeration system.
Afterward, replace the filter, evacuate it, and recharge with refrigerant.
3. Refrigeration system is clogged with dirt
Analysis of Problem
Coarse-grained dirt and refrigerant oil tend to settle in and clog the capillary
inlet. If considerable dirt accumulates there, the whole filter screen may be
blocked, preventing the refrigerant from passing through. This problem exhibits
some of the same symptoms as when the refrigeration system is clogged with ice,
namely higher gas suction pressure, lower temperature of discharged gas, and
no sound of gas flowing in the evaporator. The difference between the two
problems is that if the clogging is caused by dirt, tapping the suspicious clogged
point(s)—normally in the capillary or in the connection joint of the filter—may
cause the refrigerant to flow through partially, resulting in some change, whereas
if it is heated with a hot towel, no change will occur. After dismissing the
possibility that the clogging is due to ice, it is safe to assume the clogging is
caused by dirt.
Solution
Dismantle the system, remove the dry filter, purge the tubing with nitrogen,
install a new filter, evacuate it, and charge it with refrigerant.
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Maintenance Service and Troubleshooting
4. Clogged filter
Analysis of Problem
A completely clogged filter rarely happens. When this problem does occur, it
is usually caused by a buildup of paste-like matter, dust, or dirt on the filter after
the refrigerator has been in use for a long period of time. Sometimes, tapping the
filter may remove some of the blockage. When the filter is clogged, its
temperature will be cooler than normal.
Solution
The same as prescribed in the “Refrigerating system clogged with dirt”
section.
5. Broken gas suction and discharge valve blocks
Analysis of Problem
The compressor works by opening and closing the gas suction and discharge
valves in order to draw in and discharge the refrigerant. If the valve block is
broken, the refrigerant cannot be discharged, preventing refrigeration.
Solution
It can be difficult to differentiate this problem from others because they often
share similar symptoms. When repairing, listen attentively for any abnormal
sound(s) coming from the compressor—sometimes the broken pieces of valve
block may strike against the cylinder. Next, feel the compressor casing to
determine if it is too hot. Then, with pressure gauges, measure the pressures at
the high and low pressure ports of the compressor. If the gas suction valve block
is broken, the suction pressure will be extremely high and its gauge pointer will
swing violently. If the gas discharge valve block is broken, the discharge
pressure will be extremely high and its gauge pointer will also swing drastically.
In both cases, stop the compressor at once, and, if possible, open the cylinder
cover to check the valve block, and then repair or replace.
C. Compressor Suddenly Stops
Often when the compressor suddenly stops during operation, the gas suction
pressure and/or discharge pressure have exceeded their respective prescribed
ranges. When this occurs, the pressure-operated protective relay automatically
shuts off the compressor. Below are some of the common reasons for high gas
discharge pressure and low suction pressure.
1. Stoppage due to excessively high gas discharge pressure
1a. Excess refrigerant
Analysis of Problem
Loose frost and poor refrigerating effect may occur if excessive refrigerant is
charged into the system. Excessive refrigerant will occupy additional space in the
evaporator, which will reduce its heat dissipating area, and “liquid striking”
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Maintenance Service and Troubleshooting
may occur as well. Meanwhile, condensation may occur on the gas return tube,
and the gas discharge pressure will rise. When it reaches the maximum value,
the protective relay will activate and shut off the compressor.
Solution
Open the tubing, evacuate, and charge the system with the proper quantity of
refrigerant.
1b. Air left in the system
Analysis of Problem
Residual air in the system will circulate with the refrigerant in the system. The
major symptoms caused by this problem are poor refrigerating effect, higher gas
discharge pressure, and higher discharged gas temperature (the gas discharge
tubing is considerably hot). The gas discharge pressure will exceed its normal
value when the compressor has run for an extended period of time, thus making
the protective relay activate and shut off the compressor.
Solution
Exam how the air was left in the refrigerating system. Generally, there are
three possibilities:
i. the air was sucked into the system during a careless repair,
ii. it was not completely purged when evacuating the system, or
iii. there are leak points at the low-pressure end of the refrigerating
system. Leak points appear mainly in low-temperature parts
because the evaporation temperature is lower in low-temperature
devices; it is easier for air to enter the system in such areas.
Once it has been determined that air is in the system, open the tubing,
evacuate it, and charge it with refrigerant.
2. Broken due to electrical issues
2a. Thermostat is out of order
Analysis of Problem
If the thermostat is not in good working order or its temperature sensor has
been installed improperly, frequent stopping is likely to occur.
Solution
Try to adjust the temperature sensor's position until the compressor can be
started and stopped normally. If this cannot be achieved and the compressor
continues to suddenly stop, it is most likely that the mechanical parts or contacts
are out of order. Therefore, disassemble the thermostat, make a thorough
checkup, and repair it.
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Maintenance Service and Troubleshooting
2b. Overload of electric motor
Analysis of Problem
The motor might stop running if:
i. too many items are placed inside the refrigerator, which will cause
the thermal load to exceed its refrigerating capacity, or
ii. The power supply voltage drops considerably, causing the current
flowing through the motor to increase drastically, activating the
thermal protector and blowing a fuse. If the motor is still running, its
windings will be burned out.
Solution
Reduce the thermal load, paying close attention to the variation in the power
supply voltage.
2c. Abnormal thermal protection
Analysis of Problem
The compressor current is within its normal range, but the thermal protector
activates repeatedly.
Solution
Replace the thermal protector with a new one.
3. Blockage due to other causes
Normal Stoppage
A thermostat generally controls when the compressor starts and stops. When
the temperature in the refrigerator reaches its desired value, the thermostat will
shut down the compressor automatically. Never confusion this normal operation
as a malfunction. Be sure to differentiate this normal occurrence from real issues
while servicing.
D. Compressor Will Not Start
If the compressor does not start, find the root of the problem by conducting
a step-by-step checkup. There are many possible causes, including electrical
and mechanical.
1. Check if power supply is connected to the compressor circuit
Analysis of Problem
If the compressor will not start, usually the problem will manifest itself in the
power supply circuit, such as power failure, poor switch contact, or blown fuse.
Make a comprehensive analysis of the situation, find the cause, and take
measures to fix the problem.
Solution
a. Check the power circuit input—connected to the light switch—to see if
there is voltage in the power supply. This can be determined with a
voltmeter or a test pencil. If a blown fuse is found, determine and remove
its cause, and replace it with a new one with the same specifications.
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Maintenance Service and Troubleshooting
b. Check the compressor accessories, including its thermal protector and
relay. If the thermal protector is damaged, the compressor cannot be
powered on. If the relay is out of order, the motor will not run and a
humming will sound when the compressor is turned on. If this happens,
shut it down immediately or the motor windings will burn out if this
condition persists.
c. Check the relay contacts and plugs to see if they are in perfect order and
working. Poor contact may cause the motor to stop running or to hum.
2. Check if circuit voltage is normal
Analysis of Problem
If the circuit voltage is lower than its rated value, it will be difficult to start the
motor, and a humming will be heard.
Solution
Measure the voltage with a voltmeter. If it is too low, instruct the owner to buy
a stabilizer to increase the voltage for normal operation.
3. Check if contacts of thermal relay are closed
Analysis of Problem
The contacts of the thermal relay are sometimes open due to a leakage of
temperature-sensing agent from the temperature sensor.
Solution
Remove the relay cover to check its contacts. If they are open, this means
the original setting was not properly positioned or the temperature-sensing agent
has leaked. Adjust the contacts of the temperature sensor towards the low
temperature direction. Once completed, check if contacts have been closed. If
they are still open, dismantle the temperature-sensing disc and immerse it into
warm water to see if the contacts activate. If they do not, the temperaturesensing agent has leaked out, and the thermostat must be replaced.
4. Motor problems and other electrical failings
4a. Motor windings have been burned or short-circuited between cycles
Analysis of Problem
When motor windings have been burned or short-circuited, the fuse will blow
repeatedly, especially when the light switch is closed.
Solution
Check the terminals and outer casing to see if they are short-circuited, and
measure the resistance of each phase with a voltmeter. If short-circuited or the
resistance of a phase is low, this means the windings are short-circuited and/or
the insulation layers have deteriorated or been burned.
A multimeter can also be used. If the insulation resistance is lower than two mega
ohms (Ω), this means that the insulation layer is damaged. If the motor has been
burned, repair it or replace it with a new one.
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Maintenance Service and Troubleshooting
4b. Faulty control relay
Analysis of Problem
Overheating, burnouts, and/or wearing of control relay contacts will generally
occur. All these will cause poor contact in electricity.
Solution
Dismantle the control relay to repair or replace it with a new one.
4c. Defective electric contactor in thermostat
Analysis of Problem
Damaged contactor and the temperature-sensing agent has leaked.
Solution
Replace the old/broken contactor with a new one.
4d. Check the terminals for loose connection and electrical circuits for other
abnormal occurrences.
5. Mechanical problems in compressor
Analysis of Problem
a. Shaft seizure: This is mainly caused by poor lubrication, such as
insufficient lubricant, clogged lubricant oil line, or irregular application of
lubricant. Dirt and other impurities in the lubricant will increase its
gumminess and cause the shaft to seize up. Copper plating may also
cause shaft seizure.
b. Piston seizure: This is caused when the fit clearance between the piston
and cylinder is too small or has expanded due to heat.
These problems have most likely happened if the refrigerator is turned on,
but the compressor will not start, while it emits a slight humming, and, seconds
later, the thermal protective relay activates and opens the contacts. This process
will occur repeatedly, and the compressor will remain inactive.
Solution
Replace compressor.
E. Compressor Will Not Stop
The compressor will run continuously for several hours or without end. There
are many reasons why this might happen.
1. Common Causes
a. Too much food is placed or is too densely packed in the refrigerator,
resulting in poor ventilation or inadequate conditions for temperature
sensing.
b. The ambient temperature is too high, creating poor ventilation and heat
dissipation.
c. The control system is out of order.
d. Control system functions normally, but there is an issue in the
refrigeration system.
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2. Temperature is set incorrectly
Analysis of Problem
The temperature control knob is set to the "coldest" setting. This setting is for
fast freezing and can cause continuous running because the temperature for the
compressor to power off is too low, so it won't stop running until it reaches the
"coldest" temperature.
Solution
Check the temperature control knob to see if it is set to "coldest."
3. Thermostat is malfunctioning
Analysis of Problem
When the thermostat does not work properly, it will make the compressor run
continuously, causing the temperature to drop. The issue usually lies in the fact
that the contacts of the thermostat cannot be released.
Solution
Dismantle the thermostat and make a thorough examination. If it is out of
order, replace it with a new one.
4. Evaporation temperature is too high
Analysis of Problem
Refrigerant leakage and clogging in a refrigeration system will affect the
refrigerating capacity. Due to a lower refrigerating capacity, the refrigerator
temperature cannot reach its rated value and the thermostat will malfunction, so
the compressor will continue to run. When the evaporation temperature in the
system is too high, the temperature-sensing agent in the temperature sensor will
also be hot, so the thermostat will be unable to cut off the power supply to the
compressor and stop it.
Solution
If the amount of refrigerant is insufficient, recharge the system with refrigerant.
If clogging occurs, disassemble the clogged part. If the evaporation temperature
is too high, resolve this problem with an appropriate amount of refrigerant.
5. Damaged thermal insulation layer and/or door seal
Analysis of Problem
When the thermal insulation layer inside the casing deteriorates or the door
seal does not touch the doorframe, the temperature in the refrigerator will rise
and make the compressor continuously run.
Solution
Check the thermal insulation layer for damage. If damaged, repair it. If the
door has deformed or the door seal does not close tightly against the casing,
repair or replace seal/gasket.
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Maintenance Service and Troubleshooting
F. Leakage Current
1. Slight leakage current
Electrical insulator has deteriorated due to dampness, thus resulting in a
slight leakage current.
2. Serious leakage current
Refrigerator has become electrically charged due to an electrical problem
or faulty wiring in power cord or outlet. This is extremely dangerous.
3. Leakage current test
a. Slight leakage current: A tingly sensation will be felt if the metal parts of
the refrigerator are touched. When tested with a test pencil, the neon
light will turn on. In that case, determine if the grounding was properly
done. If it was, turn off the refrigerator, and check the insulation of the
electrical circuits with a voltmeter.
b. Serious leakage current: Never touch the refrigerator casing, its door
handle, or other metal parts. Test the refrigerator with a test pencil; the
test pencil should light up brightly. Next, measure the resistance between
the power cord and the casing with a voltmeter; the reading should be
zero ohms (Ω). At worst, there is a blown fuse. Check the three-prong
outlet to see if the live and neutral wires were inverted, which will turn the
power plug’s ground prong into a live wire. Another possibility is that the
live wire and neutral line of the outdoor power supply circuit have been
inversely connected, making the neutral wire become live.
G. Strong Vibrations and Loud Noises
1. Refrigerator placed improperly
a. Uneven ground will cause the refrigerator to be unsteady, causing large
vibrations and loud noises during operation.
b. If the leveling screws have not been adjusted properly, vibrations and
noises will occur even if the refrigerator has been placed on a levelled
ground.
2. Abnormal noise from compressor
Suspended springs inside the compressor casing are out of balance and
strike against the casing. Worn compressor parts may also cause noise.
3. Echo in tubing and loose parts
Improperly laid or tightly packed tubes or loose parts may cause vibrations
and noise.
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4. Inspection guidelines
To find the source(s) of noise, press the vibrating spot while the
refrigerator is in operation and listen if the vibration becomes weak or
disappears. If the refrigerator has not been levelled, put a leveler on the
refrigerators top and adjust the leveling screws. If noise is coming from the
compressor, hit different spots on the side of the casing with a regular or
rubber hammer with a wooden block in-between to determine if the
suspended springs are out of balance or have been caught in something.
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