EdgeStar CWB8420DZ, CWB1760FD Service Manual
EdgeStar, 8606 Wall St, Suite 1800, Austin, TX 78754
support.edgestar.com • service@edgestar.com • edgestar.com
*Warranty service should be performed by an authorized service representative only.
SERVICE MANUAL
CWB1760FD
CWB8420DZ
EdgeStar 24 Inch Built-In
Wine and Beverage Cooler
with French Doors
EdgeStar 24 Inch Built-In Wine
and Beverage Cooler
Document Type: Service Manual
Version: V1.0 04102018
CAUTION: READ ALL SAFETY PRECAUTIONS IN THIS
MANUAL BEFORE SERVICING THE UNIT
Contents
1. Safety Warnings .......................................................................................................................................... 5
1.1 Warnings and Safety Instructions ......................................................................................................... 5
1.2 Safety Instructions for R600a Refrigerant ............................................................................................ 8
2. Refrigeration System .................................................................................................................................. 9
2.1 Refrigerant Cycle Diagrams .................................................................................................................. 9
2.2 Refrigeration Process .......................................................................................................................... 11
2.3 Refrigeration System Components ..................................................................................................... 12
2.4 Service Precautions for R600A Refrigerant ............................................................................................ 13
2.5 Performance Checks ........................................................................................................................... 15
2.6 Leak Testing ........................................................................................................................................ 16
3.
Exploded Diagrams and Part Lists
............................................................................................................. 17
3.1 CWB1760FD Exploded Diagram ......................................................................................................... 17
3.2 CWB1760FD Parts List ........................................................................................................................ 18
3.3 CWB8420DZ Exploded Diagram ......................................................................................................... 19
3.4 CWB8420DZ Parts List ........................................................................................................................ 20
4.
Electronic Controls
.................................................................................................................................... 21
4.1. Modes ................................................................................................................................................ 21
4.2 Alarms ................................................................................................................................................. 21
4.3 Other Functions .................................................................................................................................. 22
4.4 Fan Operation ..................................................................................................................................... 22
4.5 Control System Self-Check .................................................................................................................. 23
4.6 Test Mode ........................................................................................................................................... 23
5. Schematic Diagrams ................................................................................................................................. 23
5.1 CWB1760FD Wiring Diagram .............................................................................................................. 23
5.2 CWB8420DZ Wiring Diagram .............................................................................................................. 24
5.3 Power PCB .......................................................................................................................................... 24
5.4
Control PCB ........................................................................................................................................ 25
6. Compressor Compartment Components ................................................................................................. 26
7. Reversing the Door Swing (CWB8420DZ) ................................................................................................. 27
8. Replacing Main Components .................................................................................................................... 28
8.1 Replacing the Control PCB (CWB1760FD) ........................................................................................... 28
8.2 Replacing the Evaporator Fan and Temperature Sensor (CWB1760FD) ............................................ 29
8.2.1 Sensor Test Resistance Table ....................................................................................................... 30
8.3 Replacing Components In and Around the Middle Divider (CWB8420DZ) ........................................ 31
8.3.1 Replacing the Fan and Control PCB in the Middle Divider (CWB8420DZ) .................................. 32
8.3.2 Replacing the Evaporator Fan and Temperature Sensor in the Upper Zone (CWB8420DZ) ...... 34
8.3.3 Replacing the PTC Heater, Fan and Temperature Sensor in the Lower Zone (CWB8420DZ) ..... 34
8.4 Replacing the Power PCB (CWB1760FD and CWB8420DZ) ................................................................ 35
8.5 Replacing the Condenser Fan (CWB1760FD and CWB8420DZ) ......................................................... 35
8.6 Replacing Kick Plates .......................................................................................................................... 36
8.6.1 Kick Plate on CWB1760FD ........................................................................................................... 36
8.6.2 Kick Plate on CWB8420DZ ........................................................................................................... 37
8.7 Replacing LED Lights (CWB1760FD & CWB8420DZ) ........................................................................... 38
8.8 Replacing the Evaporator Assembly ................................................................................................... 39
8.9 Replacing the Compressor, Compressor PTC Starter and Overload Protector ................................. 40
8.10 Replacing the Filter Dryer ................................................................................................................. 40
8.11 Replacing the Condenser .................................................................................................................. 41
8.12 Leveling the Door(s) and Hinge Adjustments ................................................................................... 42
8.13 Replacing the Door Gasket ............................................................................................................... 42
9. Troubleshooting ....................................................................................................................................... 43
9.1 Troubleshooting Guide ....................................................................................................................... 43
9.2 Diagnostic Guide ................................................................................................................................. 45
9.3 Troubleshooting the Refrigerant System ........................................................................................... 47
9.4 Special Detailed Diagnosis .................................................................................................................. 48
9.4.1 Testing the Power PCB & Display/Control PCB ............................................................................ 48
9.4.2 Testing the Condenser Fan ................................................................................................... 48
9.4.3 Testing the Evaporator Fan .................................................................................................. 48
9.4.4 Testing the Fan in the Middle Divider (CWB8420DZ) ........................................................... 49
9.4.5 Testing the Heater Fan (CWB8420DZ) .................................................................................. 49
9.4.6 Testing the PTC Heater (CWB8420DZ).................................................................................. 49
9.4.7 Overload Protector .................................................................................................................... 50
9.4.8 PTC Starter ................................................................................................................................... 50
9.4.9 Run Capacitor .............................................................................................................................. 51
9.4.10 Abnormal Vs. Normal Noise ...................................................................................................... 52
9.4.11 Evaporator Freezing .................................................................................................................. 52
9.4.12 Solenoid Valve (CWB1760FD) .................................................................................................... 53
9.5 Display Error Codes............................................................................................................................. 53
9.5.1 “E1” .............................................................................................................................................. 53
9.5.2 “E2” .............................................................................................................................................. 53
9.5.3 “E3” .............................................................................................................................................. 53
9.5.4 “E4” .............................................................................................................................................. 54
9.5.5 “E5” .............................................................................................................................................. 54
9.5.6 “E6” .............................................................................................................................................. 54
9.5.7 “E7” .............................................................................................................................................. 54
10. FAQs ........................................................................................................................................................ 55
WARNING
Before servicing, make sure to unplug the appliance.
After servicing replace all parts before operating the appliance.
Failure to do so could result in death, electrical shock or personal injury.
All servicing must be carried out by qualified technicians. Repairs done incorrectly
may cause considerable risk to the user.
For units with R600a refrigerant make sure to release all the refrigerant before servicing
otherwise fires or explosion can
result.
Personal Injury Hazard - To prevent unnecessary risk of fire, electrical shock or
personal injury, all wiring and grounding must be done in accordance with National
Electrical Code and local codes and ordinances.
1. Safety Warnings
1.1 Warnings and Safety Instructions
1.2 Safety Instructions for R600a Refrigerant
2. Refrigeration System
2.1 Refrigerant Cycle Diagrams
CWB1760FD
1. Compressor
2. Spiral Tube
3. Condenser Fan
4. Condenser
5. Hot Pipe
6. Process Tube
7. Filter Dryer
8. Solenoid Valve
9. Capillary
10. Evaporator Fan
11. Accumulator
12. Evaporator
13. Suction Tube
14. Process Tube
CWB8420DZ
1. Compressor
2. Spiral Tube
3. Condenser Fan
4. Condenser
5. Hot Pipe
6. Process Tube
7. Filter Dryer
8. Capillary Tube
9. Evaporator Fan
10. Accumulator
11. Evaporator
12. Suction Tube
13. Process Tube
2.2 Refrigeration Process
All refrigeration units cool by removing heat from the cabinet rather than pumping in cool air.
In a
conventional refrigeration unit, liquid refrigerant enters the evaporator and vaporizes due to the
low pressure, creating a very cold surface which removes heat from inside the cabinet. This causes
the refrigerant to boil into a vapor state and be drawn into the compressor. The compressor
pressurizes the vapor and pumps it into the condenser. The hot vapor in the condenser gives off
the heat into the room. As the vapor cools, it condenses back into a liquid and returns to the
evaporator to start the process over again. The system continually soaks up the heat inside
the refrigerator and deposits the heat back into the room.
The compressor of the refrigeration system serves two purposes: it ensures movement of
the refrigerant throughout the system and it increases the pressure and temperature of the
vapor received from the suction line and pumps the refrigerant into the discharge line. The
condenser receives this high temperature, high pressure refrigerant and allows the heat to
be released into the cooler surroundings. This heat removal "condenses" the refrigerant
vapor into a liquid.
The hot pipe is the first part of the condenser routed around the cabinet to help prevent
moisture formation.
The filter dryer is installed at the end of the condenser to capture moisture which may be
present in the system.
The capillary tube meters the flow of refrigerant and creates a pressure drop. Size and
length of the capillary is critical to the efficiency of the system.
As the refrigerant leaves the capillary tube and enters the larger tubing of the evaporator, the
sudden increase in tubing diameter, and the pumping action of the compressor, form a low
pressure area. The temperature of the refrigerant drops rapidly as it changes to a mixture of
liquid and vapor. In the process of passing through the evaporator, the refrigerant absorbs
heat from the storage area and is gradually changed from a liquid and vapor mixture
(saturated refrigerant) into a vapor.
The suction line returns this low pressure vapor from the evaporator back to the
compressor, and the cycle starts again.
Part of the capillary tube is soldered to the suction line which forms a heat exchanger.
Heat from the capillary tube is thus transferred to the suction line to superheat the
refrigerant there and at the same time this further cools the liquid in the capillary tube. This
cools the refrigerant before it enters the evaporator and also heats the refrigerant before it
enters the compressor to ensure a vapor state.
2.3 Refrigeration System Components
Compressor
The compressor is the "heart" of the refrigeration unit, consisting of an electrical motor and a
"pump" sealed inside a steel case. The compressor used on R134A refrigerant systems is
virtually the same in external appearance as the compressor used with R600a refrigerants.
However, due to changes in lubricants and other internal differences, the compressors are not to
be interchanged, otherwise system failure will result. If a new compressor is to be installed, pull
one of the plugs to ensure that it is properly pressurized. If no pressure is observed, do not use
the compressor. If unit is pressurized, reinstall the plug and keep the compressor sealed until it
is installed and ready for solder connections. Whenever the compressor is replaced, the sealed
system must be flushed especially for R134a system.
Condenser
The condenser is a long folded tube with steel wires which receives the hot, high pressure vapor
from the compressor. While the most common problem is keeping the condenser clean from lint
and dirt buildup which prevents proper airflow and the required transfer of the heat to the
surroundings, it is possible that due to an un-repairable leak or a non-removable restriction, the
condenser could require replacement. Do not remove the plugs on the condenser inlet and outlet
tubes until the new condenser is mounted in place and made ready for brazing. The inlet side will
connect to the hot pipe and the outlet to the filter dryer for built-in models and for built-in models
the condenser can be replaceable. But for free-standing models the inlet side will connect to the
discharge pipe of compressor and the outlet to filter dryer, it is non-replaceable.
Evaporator
The evaporator is a fin tube type within the rear side of cabinet and can be replaced. If a leak
is present in the evaporator, it is not repairable and must be replaced. After mounting the
evaporator in place, connect the capillary tube to the replacement filter drier. Again, whenever
the evaporator assembly is replaced the sealed system should be flushed.
Filter Dryer
Whenever the sealed system is entered, the filter dryer must be replaced. The filter dryer is
stamped with an arrow which indicates the direction of refrigerant flow. The dryer inlet has two
lines. One connects to the condenser and the other will be used as a process tube through
which the system sweep and final charge will be made. The dryer outlet will be connected to the
capillary tube. Care should be taken to ensure that the capillary is not inserted too far into the filter
dryer to make contact with its internal screen, yet in far enough to prevent restricting the small
diameter capillary tube opening with the solder alloy.
Hot Pipe
The hot pipe is a non-replaceable component of the sealed system routed within the walls of the
cabinet. To diagnose the hot pipe, the tubing must be isolated from the sealed system. If the
hot pipe fails to hold the vacuum, a heater repair assembly is to be installed and the hot pipe
bypassed by connecting the condenser outlet tube directly to the inlet of filter drier.
Capillary
The capillary tube meters the flow of refrigerant and creates a pressure drop. Size and length of
the capillary is critical to the efficiency of the system.
2.4 Service Precautions for R600A Refrigerant
Features of R600a refrigerant
Achromatic and odorless gas.
Flammable gas with ignition (explosion) at 494°C.
Upper/lower explosion limit: 1.8%~8.4%/Vol.
Features of the R600a refrigeration unit
Charging of around 60% refrigerant compared with a R134a model
The suction pressure is below 1bar (abs) during the operation.
Because of its low suction pressure, the external air may flow in the cycle system when the
refrigerant leaks, and will cause a malfunction in the compressor.
The displacement of compressor using R600a must be at least 1.7 times larger than that of
R134a.
Any type of dryer is applicable (XH-5, 7, 9).
The EVAPORATOR or any other cycle part that has welding joint is hidden in the foam. (If not
hidden inside, the whole electric parts must be tested with the LEAKAGE TEST according to the
IEC Standard.)
The compressor has label of the refrigerant R600a.
Only a qualified technician should access the system.
Installation place
Must be well ventilated.
Must be 20 cubic meters or larger.
Must be no-smoking area.
No ignitable factors may be present.
Tools needed
Refrigerant cylinder (MAX NET 300g)
Manometer
Vacuum pump (600L/min)
Piercing Clamp
Quick coupler • Hoses (5m-1EA, 1m-3EA)
LOKRING
Portable Leakage detector (3g/year)
Nitrogen cylinder (for leakage test)
Concentration gauge
Make sure before servicing
Confirm Refrigerant by checking Name Plate and the label on the compressor.
With R600a you must not weld or apply a heat source until refrigerant has been vented.
Recharging the Compressor
Before refilling the refrigerant, you must perform the test according to “TROUBLESHOOTING
GUIDE”. When the defects are found, you must discharge the residual refrigerant (R600a) in the
outdoors. For discharging the refrigerant R600a, break the narrow portion of tube extension by
hand or with a pipe cutter. Leave it for
30min in outside to stabilize the pressure.
Then, check the pressure by piercing the
filter dryer part with piercing pliers. If the
refrigerant is not completely discharged,
let the refrigerator stand for 30 more min
outside.
Attach a service tube installed with a
Schrader valve (one-way valve). Then, connect the Schrader valve (one-way valve) to the pump that
is connected to the discharging hose leading to the outside. When discharging the residual
refrigerant, repeat 3 cycles that includes 3min of the pump running->pump off->30sec of the
compressor running.
After the refrigerant (R600a) is completely discharged, repair any defective parts and replace the
filter dryer. Connect the Schrader valve to pump with the coupler then turn the vacuum pump on.
Let the pump run until the low-pressure gauge indicates the vacuum (gauge pressure 0,
absolute pressure -1atm or -760mmHg). Recommended vacuum time is 30 min. Charge the
N2 gas in order to check for leakage fro m welding points. If leakages are found, repair the
defects and repeat the vacuum process.
After the system is completely vacuumed, fill it with R600a up to what has been specified on
your unit Rating Label. The amount of refrigerant must be precisely measured within the error of
±2g by an electron scale.
If you use the manifold connected with both the R600a cylinder and the vacuum pump
simultaneously, make sure the pump valve is closed.
Connect the charging hose that is connected to the refrigerant cylinder to the Schrader valve installed
on the service tube. Then, charge the refrigerant by controlling the throttle valve. When you do so,
do not fully open the Throttle valve because it may make damage to the compressor. Gradually
charge the R600a by opening and closing the throttle valve (5g each time). The charging hose
must use a one-way valve to prevent the refrigerant from flowing back. Close the Schrader valve cap
after the refrigerant (R600a) is completely recharged.
After you completely recharge the refrigerant (R600a), perform the leak test by using a portable
leak detector or soap suds. Test the low pressure (suction) parts when compressor is off and high
pressure parts when compressor is on. If leaks are found, restart from the refrigerant discharging
process and repair any leaks.
After the leak test, check the temperature of each part. Check (by touch) if the CONDENSER
and Hot Pipe are warm. Confirm that frost is uniformly distributed on the surface of the
EVAPORATOR.
2.5 Performance Checks
The following general information explains several methods for checking the performance of the
refrigeration system. The correct operation of a refrigeration system is dependent upon the proper
function of each of the parts comprising the system. If the system does not operate properly (long
run periods, warmer than normal temperatures), the trouble may be caused by one of the following
conditions:
Restricted Capillary Tube
The opening of a capillary tube is about the same diameter as the period at the end of this
sentence. Because of this, it is easy to restrict the tube. Extra precautions should be taken when
any service procedure involves moving or touching the capillary tube. The slightest kink can
cause a complete tube restriction.
Restrictions of the capillary tube may be caused by: (1) moisture freeze-up (2) foreign particles
lodged in the tube or (3) a bend or kink.
If the capillary tube is restricted, there will be a noticeable lack of frost on all cooling surfaces. The
compressor may operate for a short period of time and cycle on the overload. When moisture
freeze-up causes a restriction it usually occurs at the outlet end of the capillary tube. Normally,
frost buildup can be detected in this area.
At the discharge end of the capillary, apply heat by using the hairdryer. If there is enough head
pressure, and if the restriction is caused by moisture freeze-up, you will be able to hear a gurgling
noise as the heat releases the refrigerant through the tubing. It is possible that this moisture will
be absorbed by the filter drier and remedy the trouble. However, if the freeze-up reoccurs, you
must replace the filter drier.
A kink in the capillary tube will have the same symptoms as a moisture freeze-up, except for the
accumulation of frost. Where possible, check the capillary tube and straighten any kinks to relieve
the restrictions. Check the unit’s performance. If the condition persists, replace the defective
part. If the freeze-up condition does not exist and there is not a kink, you can assume that a
foreign particle is causing the restriction. The only remedy in this case is to replace the restricted
part.
Partial Restriction In Low Side Tubing
Bent tubing, foreign matter, or moisture in the system may cause a partial restriction in the low
side tubing. This is usually indicated by frost-free tubing between the restriction and the capillary
tube and by frost-covered tubing between the restriction and the suction line. The restriction acts
like a second capillary tube, increasing the pressure ahead of it (warming) and decreasing the
pressure beyond it (cooling). To confirm the existence of a restriction in the low side tubing,
perform operational pressure checks.
Slow Leak In System
On compressor systems, long run time will be noticed during the early stages of a leak. As the
refrigerant continues to escape, the compartment will gradually warm up and the compressor will
run continuously.
Incorrect Refrigerant Charge
The sealed unit may have too much refrigerant (overcharged system) or too little refrigerant
(undercharged system). The troubleshooting guide will inform you on how to recognize a system
with these defects.
An overcharged system may have a frost back condition appearing on the suction line. When the
compressor stops, the frost melts and drips on the floor. A heat exchanger separation will also
cause this symptom.
An undercharged system, depending on the degree of undercharge, will operate with
temperatures above normal and the compressor run time will be increased. The more
undercharged, the higher the temperature will be and the longer the run time. An undercharged
system must be purged, evacuated, and recharged with the proper amount of refrigerant.
Before recharging, test for refrigerant leaks.
2.6 Leak Testing
Once it has been determined through proper diagnosis that a leak is present in the sealed system,
attempt to find the leak before opening the system if possible. To check the high side for leaks, be
sure that the compressor is running. During run time the high side pressure is greater. To increase
the pressure slightly, stop the condenser fan blade or block the air flow through the condenser. To
check the low side for leaks, stop the compressor. During off times, the low side pressure will
increase to equalize with the high side. By warming the evaporator, this pressure will increase. If
too much refrigerant has leaked out to create enough pressure to locate the leak, add 2 ounces of
the proper refrigerant to the system and proceed with the test procedure.
The presence of oil around a tubing joint usually indicates a leak. Care must still be taken to
pinpoint the exact location. Remember to use a leak detector compatible with R600a. A sealed
system component, such as the evaporator or hot pipe, should not be condemned unless a nonrepairable leak is confirmed. This should be determined by either locating the actual leak or by
isolating the component from the rest of the system and determining if it holds pressure or a
vacuum.
3.
Exploded Diagrams and Part Lists
3.1 CWB1760FD Exploded Diagram
3.2 CWB1760FD Parts List
No.
Description
Qty.
No.
Description
Qty.
1.
Cabinet
1
26.
Metal Rack
3
2.
Left Top Hinge
1
27.
Door Switch
2
3.
Plastic Post
22
28.
Extended Ventilation Grill
1
4.
Evaporator Assembly
2
29.
Ventilation Grill
1
5.
Right Top Hinge
1
30.
Right Bracket
1
6.
Light Cover
2
31.
Lock Assembly
2
7.
LED Light
2
32.
Door Axle
2
8.
Fan Motor
2
33.
Bottom Hinge Plate
2
9.
Air Channel Cover
2
34.
Left Bracket
1
10.
Fan Guard
2
35.
Bottom Bracket
1
11.
Thermistor
2
36.
Condenser
1
12.
Thermistor Supporter
2
37.
Power Cord
1
13.
PCB Box
1
38.
Compressor Base
1
14.
Control PCB
1
39.
Compressor
1
15.
PCB Supporter
1
40.
Solenoid Valve
1
16.
Control Panel Film
1
41.
Fan Motor Supporter
1
17.
Glass Door (Right)
1
42.
Fan Motor
1
18.
Lock Bracket
2
43.
Leveling Leg
4
19.
Handle
2
44.
Water Tray
1
20.
Screw
4
45.
Rear Grille
1
21.
Door Gasket
2
46.
Electrical Box Cover
1
22.
Door Switch
2
47.
Power PCB
1
23.
Glass Door (Left)
1
48.
Electrical Box Base
1
24.
Full Shelf
5
49.
Filter Dryer
1
25.
Shelf Front
3
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