Kuppersbusch IKEF 248-5 User manual

Refrigerators
IKEF 248-5
IKEF 238-5

Service Manual: H8-420-02-06
Responsible: Uwe Laarmann KÜPPERSBUSCH HAUSGERÄTE AG
E-mail: [e-mail]
Tel.: [phone] Kundendienst
Fax: [phone] Postfach 100 132
Date: 01.04.2005 45801 Gelsenkirchen

Service Manual 3
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Contents
1. Safety instructions ......................................................................................................... 4
2. Introduction..................................................................................................................... 5
2.1 General.................................................................................................................. 5
2.2 Measuring the temperature ................................................................................... 6
2.3 Air flow................................................................................................................... 7
3. Appliance components .................................................................................................. 8
3.1 Front view.............................................................................................................. 8
3.2 Rear view .............................................................................................................. 9
4. Cooling circuit .............................................................................................................. 10
5. Electric system ............................................................................................................. 11
6. Function chart............................................................................................................... 12
7. How the refrigerators operate ..................................................................................... 13
7.1 IKEF 238-5 .......................................................................................................... 13
7.2 IKEF 248-5 .......................................................................................................... 16
7.3 Acoustic alarm (both models).............................................................................. 17
8. Accessing the components in the keep-fresh cooling zone .................................... 18
8.1 Battery-driven evaporator and evaporator sensor............................................... 18
8.2 0° sensor ............................................................................................................. 19
9. Accessing the components in the refrigerator.......................................................... 20
9.1 Fan and refrigerator sensor................................................................................. 20
9.2 Control panel ....................................................................................................... 22
10. Design for models with an air filter............................................................................. 26
11. Technical features ........................................................................................................ 27
11.1 IKEF 238-5 .......................................................................................................... 27
11.2 IKEF 248-5 .......................................................................................................... 27

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1. Safety instructions
Danger!
Repairs may only be carried out by a qualified electrician!
Inexpert repairs may lead to risks and damages for the user!
To prevent electric shocks, please observe the following tips:
• In the event of faults, housing and frame may be live! Prior to repairs, disconnect the appliance from
the mains!
• Touching live components inside the appliance may cause dangerous currents to flow through your
body!
• Unplug the appliance before repair!
• When inspecting live parts, a residual current operated device must be used at all times!
• Always ensure that an earthed conductor is properly connected. The ground wire resistance must 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
[Association of German Electrical Engineers] or the corresponding regulations for your country! On
completion of repairs, a function and impermeability inspection must be carried out.
• Do not touch any of the components in the appliance. The modules are also live!
• Observe ESD instructions.
Attention!
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.
Sharp edges: Use protective gloves.
Components may be electrostatic!
Observe handling precautions!

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2. Introduction
2.1 General
The IKEF 238-5 and IKEF 248-5 models are described in this manual.
The IKEF 238-5 is a refrigerator with a standard refrigerator compartment and a 4-star freezer
compartment. The PNC is type 923457xxx (195 4S).
The IKEF 248-5 is a refrigerator with a standard refrigeration compartment and a 0° keep-fresh cooling
zone. The PNC is type 923524xxx (210 CC).
The evaporator circuit of the IKEF 248-5 comprises a battery-driven evaporator in the keep-fresh cooling
zone.
The evaporator circuit of the IKEF 238-5 comprises a battery-driven evaporator in the keep-fresh cooling
zone and a tube evaporator in the 4-star freezer compartment.
The appliances are equipped with electronic controls of type ERF 2000.
Legend:
A = 4-star freezer compartment
B = Standard refrigerator compartment
C = Divider plate
D = Keep-fresh cooling zone (0°)
A divider plate is located between the standard refrigeration compartment and the keep-fresh cooling
zone. The front of the divider plate is designed in such a manner that air can circulate between both
zones.
Unlike the NO FROST refrigerator, the 0° appliance has a battery-driven evaporator without defrost
resistance and without the respective thermo switches, since defrosting of the battery is carried out by
fan operation when the compressor is switched off.

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2.2 Measuring the temperature
The temperature is measured with 3 or 4 sensors:
• Refrigerator sensor (at the fan)
• 0° sensor (on the casing of the keep-fresh cooling zone)
• Sensor of the battery-driven evaporator (on the battery itself)
• Room temperature sensor (IKEF 238-5 only)
This is part of the display electronic unit.
Legend:
A = 0° sensor
B = Sensor for the battery-driven evaporator
C = Refrigerator sensor
D = Room temperature sensor (IKEF 238-5)
The cables of sensors A, B and C have been foamed in the inside of the casing and can hence not be
replaced.

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2.3 Air flow
The cold generated by the battery-driven evaporator (located in the keep-fresh cooling zone behind the
evaporator cover E) is firstly spread by the fan located behind the fan casing C into the keep-fresh
cooling zone and then into the standard refrigeration compartment.
The air is sucked in by the fan which is located in the top part of the refrigeration compartment. It flows
through the channels and flows down to the battery-driven evaporator. The cold air is expelled from the
bottom part of the battery-driven evaporator, makes contact with the two drawers of the keep-fresh
cooling zone and travels upwards through the gap between the divider plate and the door into the
standard cooling compartment.
AIR FLOW

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3. Appliance components
3.1 Front view
The most important appliance components are:
1. Control panel
2. Butter compartment
3. Door compartment
4. Bottle shelf
5. Keep-fresh cooling zone drawer (see note a)
6. Divider plate
7. Shelves
8. Air filter (special fitting, see note b)
9. Freezer compartment door
10. Model identification plate
11. Magnet holder
Note:
a) The drawers of the keep-fresh cooling zone have regulating flaps for the humidity control function
• Regulating flap closed to maintain level of humidity.
• Regulating flap open to reduce level of humidity.
It is vital that the drawer covers be positioned correctly for the „humidity control" function to operate
properly.
b) Depending on the model, a channel may be present instead of the air filter. The channel contains
an insulation panel made of polystyrene.

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3.2 Rear view
The most important appliance components are:
A Drainage filter
B Operating condensor
C Compressor
D Additional drip cup for water (IKEF 248-5 only)
E Drip cup for water

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4. Cooling circuit
IKEF 238-5
1. Compressor
2. Evaporator
3. Frame heater
4. Dryer
5. Capillary tube
6. Tube evaporator
7. Battery-driven evaporator
(keep-fresh cooling zone)
8. Heat exchanger
IKEF 248-5
1. Compressor
2. Condensor
3. Frame heater
4. Dryer
5. Capillary tube
6. Battery-driven evaporator
(keep-fresh cooling zone)
7. Heat exchanger

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5. Electric system
Please observe the circuit diagrams for the respective models.
2 Compressor
5 Protective motor switch
13 Lamp
28 Operating condensor
41 ERF 2000 electronic unit
a yellow-green
bbrown
cblue
dwhite
eblack

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6. Function chart
Please observe the circuit diagrams for the respective models.
2 Compressor
5 Protective motor switch
13 Lamp
28 Operating condensor
41 ERF 2000 electronic unit
a yellow-green
bbrown
cblue
dwhite
eblack
LCable
N Neutral wire

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7. How the refrigerators operate
7.1 IKEF 238-5
7.1.1 Refrigerator compartment control panel
1 = Performance display (green) 6 = Display for activated superfrost
function (yellow) for rapid freezing in the
freezer compartment
2 = Cooling/OFF button 7 = Superfrost button
3 = Button for setting the temperature (for higher
temperatures)
8 = Display for activated rapid-cool
function (yellow) for intensive refrigeration
4 = Temperature display 9 = Rapid-cool refrigeration button
5 = Button for setting the temperature (for lower
temperatures)
7.1.2 Putting the appliance into operation
The buttons for setting the temperature are located at the top of the appliance on the control panel.
• Insert the plug into the wall socket.
• Press the ON/OFF button (2). The green LED (1) for power control will light up. The appliance has
now been switched on and can be switched off at any time by pressing the ON/OFF button again.
The green LED (1) will then go off.
• Press one of the plus or minus buttons (3/5). The temperature display (4) will switch over and the
PRE-SET temperature will blink.
7.1.3 Temperature setting
• Pressing on one of the plus or minus buttons will switch the temperature display over from the
ACTUAL temperature (temperature display lights up consistently) to the PRE-SET temperature
(temperature display blinks).
• Each time one of the two buttons is pressed the PRE-SET temperature moves on by 1°C.
• If neither of the buttons is pressed, the temperature display will soon (after approx. 5 seconds)
switch over automatically onto the ACTUAL temperature.
The PRE-SET temperature is the temperature that the inside of the refrigerator should have. The
PRE-SET temperature is indicated by numbers which blink.
The ACTUAL temperature is the temperature which is actually present in the inside of the
refrigerator at any given time. The ACTUAL temperature is indicated by numbers which light up
consistently.

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7.1.4 Temperature display
The temperature display (4) indicates several functions:
• For standard operation the ACTUAL temperature will be shown.
• While the temperature is being adjusted, the refrigerator temperature which has currently been set
will blink (pre-set temperature).
Attention! It is quite normal for the temperature display to indicate the actual temperature with
a slight delay.
7.1.5 Rapid-cool function
The rapid-cool function can be used to cool large quantities of food in the refrigerator quickly, e.g. for
drinks or salads for a party.
The rapid-cool function is activated by pressing button 9. The yellow display 8 will light up and the rapid-
cool function will now cool the refrigerator down intensively. On doing so, a pre-set temperature of +3°C
will automatically be set. After 6 hours the rapid-cool function will switch itself off. The original pre-set
temperature is then set again and the temperature display will show the current temperature in the
refrigerator.
The rapid-cool function can be switched off again manually at any time by pressing the rapid-cool button
9 once again. The yellow display 8 goes off.
7.1.6 Need for refrigeration in the keep-fresh cooling zone only
If there is only a need for refrigeration in the keep-fresh cooling zone:
• The compressor will operate
• The fan will rotate at a low speed (approx. 1,500 rev/min.)
−at pulse operation (8 s. ON / 8 s. OFF) when the surrounding temperature is lower than 35 °C.
−at continuous operation when the surrounding temperature exceeds 35 °C.
7.1.7 Need for refrigeration for the standard refrigeration compartment and
the keep-fresh cooling zone
If there is a need for refrigeration in the keep-fresh cooling zone and the standard refrigeration
compartment:
• The compressor will operate
• The fan will rotate at a high speed (approx. 1900 rev/min.)
−at pulse operation (8 s. ON / 8 s. OFF) when the surrounding temperature is lower than 35 °C.
−at continuous operation when the surrounding temperature exceeds 35 °C.
7.1.8 Need for refrigeration in the standard refrigeration compartment only
If there is only a need for refrigeration in the standard refrigeration compartment:
• The compressor will not operate
• The fan will rotate at a high speed (approx. 1900 rev/min.)
−at pulse operation (8 s. ON / 8 s. OFF) when the surrounding temperature is lower than 35 °C.
−at continuous operation when the surrounding temperature exceeds 35 °C.

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7.1.9 Defrosting the battery-driven evaporator
The ice which builds up on the battery-driven evaporator needs to be defrosted at regular intervals. The
battery-driven evaporator is defrosted every 4 hours of compressor operation. The defrost phase
commences when the compressor is switched off.
During the defrost phase:
• The compressor will not operate
• The fan will rotate consistently at a high speed
• The temperature in the refrigerator will drop
• The battery-driven evaporator will heat up.
The defrost phase ends when the evaporator sensor measures a temperature of +4 °C.
NOTE!
If the door is opened the fan will come to a standstill.
A magnet must be used to simulate that the door is closed. It must be installed at
the Reed element.
7.1.10 Activating the compensating heating element
The compensating heating element serves the purpose of raising the temperature in the refrigerator
compartment in order to be able to regulate the temperature at +3°C to +8°C if the surrounding
temperature is between 10°C and 38°C.
The mode of function of the compensating heating element depends on the appliance settings (pre-set
temperature) and the surrounding temperature (which is measured by the environmental sensor).
The compensating heating element is foamed into the interior of the casing and can hence not be
replaced.
a View of the refrigerator interior b Rear view of the refrigeration
(approximate position of the compensating compartment
heating elements) (prior to foaming the casing)

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7.2 IKEF 248-5
The operation of the refrigerator varies depending on the refrigeration requirement of the keep-fresh
cooling zone and the standard refrigeration compartment.
There are three possible combinations for standard operation:
• Need for refrigeration in the keep-fresh cooling zone only
• Need for refrigeration in the standard refrigeration compartment and the keep-fresh cooling
zone
• Need for refrigeration in the standard refrigeration compartment only
The following situation may also occur:
• Activation of the defrost procedure of the battery-driven evaporator
7.2.1 Need for refrigeration in the keep-fresh cooling zone only
If there is only a need for refrigeration in the keep-fresh cooling zone:
• The compressor will operate
• The fan will rotate at a low speed (approx. 1,500 rev/min.)
7.2.2 Need for refrigeration in the standard refrigeration compartment and the
keep-fresh cooling zone
If there is a need for refrigeration in the keep-fresh cooling zone and the standard refrigeration
compartment:
• The compressor will operate
• The fan will rotate at a high speed (approx. 1900 rev/min.)
7.2.3 Need for refrigeration in the standard refrigeration compartment only
If there is only a need for refrigeration in the standard refrigeration compartment:
• The compressor will not operate
• The fan will rotate at a high speed (approx. 1900 rev/min.)

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7.2.4 Defrosting the battery-driven evaporator
The ice which builds up on the battery-driven evaporator needs to be defrosted at regular intervals. The
battery-driven evaporator is defrosted every 4 hours of compressor operation. The defrost phase
commences when the compressor is switched off.
During the defrost phase:
• The compressor will not operate
• The fan will rotate consistently at a high speed
• The temperature in the refrigerator will drop
• The battery-driven evaporator will heat up.
The defrost phase ends when the evaporator sensor measures a temperature of +4 °C.
NOTE!
If the door is opened the fan will come to a standstill.
A magnet must be used to simulate that the door is closed. It must be installed at
the Reed element.
7.3 Acoustic alarm (both models)
The alarm buzzer is activated if the appliance door is left open for longer than 3 minutes.
The alarm stops sounding when the appliance door is closed.

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8. Accessing the components in the keep-fresh cooling
zone
8.1 Battery-driven evaporator and evaporator sensor
Proceed as follows in order to access the battery-driven evaporator and the temperature sensor:
1. Remove the top cover of the 0° drawer.
2. Remove the 0° drawer.
3. Remove the divider plate.
4. Loosen the two fastening screws of the 5. Pull the cover of the evaporator towards you,
evaporator cover. remove it and take out the insulation panel
made of polystyrene.
A) Sensor for the battery-driven evaporator
B) Battery-driven evaporator

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8.2 0° sensor
Proceed as follows in order to access the 0° sensor:
1. Remove the top cover of the 0° drawer.
2. Remove the 0° drawer.
3. Use a screwdriver with a flat edge and A 0° sensor
remove the protective grating of the
0° sensor

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9. Accessing the components in the refrigerator
9.1 Fan and refrigerator sensor
First remove the cover of the evaporator. Then proceed as follows:
1. Remove the top cover of the 0° drawer.
2. Remove the 0° drawer.
3. Remove the divider plate.
4. Remove the two fastening screws of the 5. Pull the cover of the evaporator towards you,
evaporator cover. and remove it.
Now remove the channel or the filter channel (if present) as follows:
1. Loosen the two fastening screws of the 2. Remove the insulation panel made of
channel (or the filter channel, if present); polystyrene (not present in appliances with
Pull the channel downwards to remove it air filters)