Kuppersbusch IKEF 248-7 User manual

Refrigerator
IKEF 248-7
IKEF 249-6
IKEF 249-7

Service Manual: H8-71-07
Responsible: U. Laarmann KÜPPERSBUSCH HAUSGERÄTE AG
E-mail: [e-mail]
Phone: [phone] Kundendienst
Fax: [phone] Postfach 100 132
Date: 08.12.2008 45801 Gelsenkirchen

Service Manual 3
For internal use only
Contents
1. Safety instructions .........................................................................................................4
2. Repair instructions.........................................................................................................5
3. Operation.........................................................................................................................6
3.1 Panel.....................................................................................................................6
3.2 Main switch............................................................................................................6
3.3 Refrigerator section temperature adjuster.............................................................6
3.4 Temperature setting range....................................................................................6
3.5 Keep-fresh cooling section temperature setting range..........................................6
3.6 Refrigerator section Super button .........................................................................7
4. Components....................................................................................................................8
4.1 Electronic controls.................................................................................................8
4.2 Keep-fresh cooling section fan..............................................................................8
4.3 Heating the refrigerator section.............................................................................8
4.4 Solenoid valve.......................................................................................................8
5. Functions ........................................................................................................................9
5.1 Cooling circuit........................................................................................................9
5.2 Start-up program .................................................................................................10
5.3 Demonstration program (sales room switching)..................................................10
5.4 Defrosting............................................................................................................10
5.5 Refrigerator section Super program....................................................................11
5.6 Test program.......................................................................................................11
5.7 Solenoid valve safety function.............................................................................11
6. Repairs ..........................................................................................................................12
6.1 Capillary tube ......................................................................................................12
7. Trouble shooting ..........................................................................................................13
7.1 NTC fault .............................................................................................................13
7.2 Error message LO...............................................................................................13
8. Technical data...............................................................................................................14
8.1 Sensor readings ..................................................................................................14
8.2 Electrical data......................................................................................................14

4 Service Manual
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1. Safety instructions
Danger!
Repairs may only be carried out by a qualified electrician!
Improper repairs can be extremely dangerous for the user.
It is essential that you observe the following instructions in order to prevent electric shocks:
• The casing and the frame may be live in the event of faults!
• Touching live components inside the appliance may cause dangerous currents to flow through your
body!
• Disconnect the appliance from the mains prior to carrying out any repair work!
• When inspecting live parts, a residual current circuit breaker must always be used!
• Always ensure that anearthed conductor is properly connected! The ground wire resistancemust not
exceed that specified in the standard! It is of vital importance for ensuring the safety of people and
the functioning of the appliance.
• On completion of repairs, an inspection must be carried out in accordance with VDE 0701 [Associa-
tion of German Electrical Engineers] or the corresponding regulations for your country!
• Do not touch any of the components in the appliance. The modules are also live!
• Observe instructions on electrostatic hazards!
• Wear safety goggles and protective gloves when handling refrigerants. Rinse your eyes with a lot of
water if refrigerant splashes into them.
Make sure you observe the following instructions:
• The appliances must be disconnected from the mains prior to all repairs. If inspections must be
carried out on live appliances, make sure you use a residual current operated device.
Attention!
Sharp edges: Use protective gloves.
Components may be electrostatic!
Observe handling precautions!

Service Manual 5
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2. Repair instructions
• Never attempt to carry out repairs by “randomly replacing” components!
• Always proceed systematically and observe the technical documentation that goes with the appli-
ance!
• Electronic circuit boards are generally not repaired; instead they are completely replaced with original
spare parts. Exceptions are documented separately.
• Pipe connections in cooling circuits are not to be soldered. Lokring connections are to be used.
• Carry out a leak test and a functional test on the cooling circuit.
• The dehumidifier is to be replaced before evacuation and filling during any intervention in the cooling
circuit.
• It is essential to replace the compressor and the dehumidifier when repair work resulting from suction
leaks in the cooling circuit is carried out. Humidity which gets into the cooling circuit will cause irrep-
arable damage to the oil in the compressor.

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3. Operation
3.1 Panel
1. Temperature display (only lights up when the outer door is open)
2. Keep-fresh cooling section operation display (only lights up when the outer door is open)
3. Super mode / freezer section operation display (only lights up when the outer door is open)
4. Temperature adjuster
5. Super button
6. Main switch
3.2 Main switch
The main switch is used for switching the refrigerator on and off.
3.3 Refrigerator section temperature adjuster
The temperature display is switched from the actual to the target temperature display when the temper-
ature adjuster is pressed. Each time the button is pressed the target temperature is changed by 1K. At
the end of the adjustment range the temperature is switched back to the original setting. Pressing the
button constantly will change the temperature every second. If the button is not pressed for 5s, the actual
temperature will be shown again.
3.4 Temperature setting range
The setting range is from 3°C to 8°C. The basic setting is 6°C.
3.5 Keep-fresh cooling section temperature setting range
• Press the temperature adjuster and keep it pressed.
• Switch on the refrigerator at the main switch.
• Keep pressed for 3s until 88 lights up and then goes off again.
• Release the temperature adjuster.
• The refrigerator section display shows the sensor setting (basic setting = 2)
• The keep-fresh cooling section temperature is adjusted in 1K steps with the temperature adjuster.
Settings can be made from 6 (warm) to 0 (cold).

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The display returns to the standard status when the temperature adjuster is not activated for 1min.
The new setting is assumed after the display has returned to the standard status.
3.6 Refrigerator section Super button
This button is used to start the Super program for the refrigerator section. Pressing this button again will
discontinue the program.
The refrigerator section display has no minus sign. There is a risk of the temperature
falling below 0°C (a 0 setting does not means 0°C).

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4. Components
4.1 Electronic controls
The control system comprises two modules. The control anddisplay module is located inthe control pan-
el. The input ports for the NTC sensor and the door contact are located on this module. The power supply
module is located under a cover in the power room. This is where the loaded components are all acti-
vated and the control module is supplied with power.
4.2 Keep-fresh cooling section fan
• The fan is switched off when the outer door is open.
• The fan is always switched on when the appliance is being defrosted.
• The fan is switched on for 30s when the outer door is closed.
• The fan will operate when the keep-fresh cooling section indicates that cooling is required.
• The fan will be switched on for 12min after standing still for 4min.
4.3 Heating the refrigerator section
The refrigerator section is heated, since it becomes too cold when the room temperature is low.
The refrigerator section heater is located on the evaporator. The heater is placed in foam and cannot be
replaced.
Heater output = 10W.
The refrigerator section heater is regulated by the room temperature:
4.4 Solenoid valve
The solenoid valve has no defined resting position. Each
switching position is reached by activating positive and nega-
tive control voltage half waves. The flexible armature of the
valve is located in the magnetic field of a permanent magnet
and activation brings it into its end position. In this position the
output port to which refrigerant is currently not to be applied is
closed by the armature. Triggering is repeated every 60s in or-
der to ensure that the armature remains in this position. The
permanent magnet (in the housing) generates an armature lock
in the required position.
Room temperature Action
21°C Heater is on when the compressor is off
15°C Heater operating continuously
1 = input
2 = keep-fresh cooling section output
3 = refrigerator section output

Service Manual 9
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5. Functions
5.1 Cooling circuit
The solenoid valve supplies the keep-fresh cooling section or the refrigerator section. The refrigerant is
first of all lead through the freezer section and then into the keep-fresh cooling section or it is simultane-
ously injected into the refrigerator section through the freezer section. The freezer section is always sup-
plied when the compressor is in operation. The freezer section does not have its own controls.
The keep-fresh cooling section has priority.
Condenser
Refrigerator section throttle
Keep-fresh
Freezer sectionRefrigerator sectionKeep-fresh cooling section
Suction pipe
Compressor
Solenoid valve
Dryer
cooling
section
throttle

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5.2 Start-up program
The start-up program is activated when the sensor temperatures (except for the room sensor) are all in
the range of 10°C to 45°C when the refrigerator is switched on. The room sensor may not fall below
-20°C and not exceed +45°C.
Program sequence
• 5s no trigger
• 5s solenoid valve
• 5s refrigerator section heater
• 5s keep-fresh cooling section fan
• 39min keep-fresh cooling section supply
• 24min refrigerator section supply
• If the electronic system detects an error, the keep-fresh cooling section fan will be activated for
15min.
• Standard operating mode
5.3 Demonstration program (sales room switching)
• Switch the refrigerator off.
• Press the temperature adjuster and keep it pressed.
• Switch the refrigerator on.
• Keep the temperature adjuster pressed until LO appears.
• Release the temperature adjuster.
All the operation functions and displays are active but no load components are triggered.
Exception: The fan continues to operate for 30s after the outer door has been closed.
The demonstration program ends when the appliance is switched off.
5.4 Defrosting
5.4.1 Refrigerator section
During initial operation of the refrigerator, the refrigerator section will begin to defrost after 10h. The re-
frigerator will always begin to defrost again after 23h 20min.
5.4.2 Keep-fresh cooling section
During initial operation of the refrigerator, the keep-fresh cooling section will begin to defrost after 10h.
The keep-fresh cooling section will always begin to defrost again after 16h.
• The keep-fresh cooling section is not supplied with power for 60min.
• It is defrosted until the keep-fresh cooling section evaporator sensor reaches 4°C or after 100min.
During defrosting the keep-fresh cooling section fan remains switched on (only when the outer door
closed).

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5.5 Refrigerator section Super program
The Super cooling function is started with the Super button. The Super LED lights up and the refrigerator
section is operated at a target temperature of 2°C. After 24h orwhen the temperature adjuster has been
pressed again, the appliance will return to normal operation.
5.6 Test program
Calling the test program:
• Switch off the refrigerator.
• Press the Super button and keep it pressed.
• Switch on the refrigerator.
• Keep pressed for approx. 5s until LO appears.
• Release the Super button.
• P0 will appear in the display.
Pressing the temperature setting button will make the test program move forward. Pressing the Super
button will activate the test step. If no button is pressed for 5min, the refrigerator will return to normal
operation. Switching off the refrigerator will also exit the test program.
P9 - Status display of the door contact
5.7 Solenoid valve safety function
If the electronic unit detects a drop in temperature in the refrigerator section during a refrigerator dwell
time, the solenoid valve is switched in 30min cycles, until the temperature in the refrigerator section is
in the normal range.
Program Function
P0 The compressor is activated.
P1 The keep-fresh section fan is activated.
P2 The refrigerator section heater is activated.
P3 The solenoid valve is activated.
P4 Break (no consumer is activated).
P5 Room temperature sensor is shown.
P6 Refrigerator section sensor is shown.
P7 Keep-fresh cooling section sensor is shown.
P8 Keep-fresh cooling section evaporator sensor is shown.
P9 Status display of the door contact.
PA Defrosting followed by transition to normal operation.
Display Function
1 0 Door closed
1 1 Door open

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6. Repairs
6.1 Capillary tube
The capillary tube of the keep-fresh cooling
section is marked yellow.
If a capillary tube has broken off direct at the
pointwhereit is lead into thesuction pipe, itcan
be repaired with two NTR lokring connections
(spare-part no. 066034).

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7. Trouble shooting
7.1 NTC fault
The resistance readings of a sensor are converted into temperatures by the electronics unit.
A sensor is recognised as being defect by the sensor when the temperatures exceed specified temper-
ature limits. Irrespective of the sensor function, the electronic unit puts the defect sensor into a certain
operating status.
7.2 Error message LO
An LO error message in the display means:
• The operating voltage is lower than 160V or higher than 264V.
• The operating frequency is lower than 45Hz or higher than 55Hz.
Cause of fault:
• An unstable mains power supply.
• A defect power supply module.
Display Sensor Temperature Function
E1 Refrigeratorsection
sensor ≥45°C, ≤-44°C Refrigerator section controls: 20min ON and 28min OFF
E3 Keep-fresh cooling
section sensor ≥45°C, ≤-44°C Keep-fresh cooling section controls 20min ON and 28min OFF
Keep-fresh cooling
section evaporator
sensor
≥45°C, ≤-44°C Defrosting the keep-fresh cooling section
sensor

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8. Technical data
8.1 Sensor readings
8.2 Electrical data
Operating voltage: The operating range of the appliance is between 160V and 264V.
Operating frequency: The operating frequency of the appliance is between 45 Hz and 55Hz.
Interior lighting 230V, 25W
Fan: 230V, 0.05A, 7W
Temp. °C R kOhm Temp. °C R kOhm Temp. °C R kOhm Temp. °C R kOhm
-40 169.1 -19 45.87 2 14.75 23 5.46
-39 158.19 -18 43.31 314.03 24 5.22
-38 149.06 -17 40.92 4 13.35 25 4.99
-37 138.66 -16 38.67 512.69 26 4.78
-36 129.93 -15 36.49 6 12.07 27 4.58
-35 121.75 -14 34.51 711.49 28 4.38
-34 114.12 -13 32.65 8 10.94 29 4.20
-33 107.03 -12 31.00 910.42 30 4.02
-32 100.43 -11 29.38 10 9.94 31 3.85
-31 94.28 -10 27.67 11 9.48 32 3.69
-30 88.73 -9 26.19 12 9.04 33 3.54
-29 83.42 -8 24.81 13 8.62 34 3.39
-28 78.47 -7 23.50 14 8.23 35 3.26
-27 73.84 -6 22.28 15 7.85 36 3.13
-26 69.52 -5 21.16 16 7.49 37 3.01
-25 65.31 -4 20.07 17 7.15 38 2.89
-24 61.52 -3 19.04 18 6.82 39 2.77
-23 57.98 -2 18.08 19 6.52 40 2.66
-22 54.67 -1 17.17 20 6.24
-21 51.57 016.32 21 5.97
-20 48.59 1 15.51 22 5.71