Kuppersbusch MW 900 User manual

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Service Manual: H4-070-14-01
Responsible: D. Rutz KÜPPERSBUSCH HAUSGERÄTE AG
Email: [e-mail]
Tel.: [phone] Kundendienst
Fax: [phone] Postfach 100 132
Date: 17.03.2000 45801 Gelsenkirchen

Service Manual MWG 1000 3
Only for internal use
Contents
1. Description of type ......................................................................................................... 4
2. Repair and maintenance ................................................................................................ 6
2.1 Technical data MWGD 900.0 ................................................................................ 7
2.2 New features ....................................................................................................... 11
2.3 Description of the components and their functions ............................................. 12
3. Repair and maintenance .............................................................................................. 13
3.1 Dismantling of the cooker hood for repair work................................................... 14
3.2 Microwave oven and cooker hood controls ......................................................... 15
3.3 Dismantling and assembling the appliance ......................................................... 16
4. Measurements and adjustments................................................................................. 23
4.1 Component testing .............................................................................................. 24
5. Installation..................................................................................................................... 26
5.1 Dimensions.......................................................................................................... 26
5.2 Methods of assembly .......................................................................................... 26
5.3 Notes on installation ............................................................................................ 27
5.4 Wiring diagram for MWG 1000............................................................................ 33
5.5 Wiring diagram for MWG 1000............................................................................ 34
5.6 Wiring diagram for MW 900.0.............................................................................. 38
5.7 Wiring diagram for MWGD 900.0 ........................................................................ 39

4 Service Manual MWG 1000
Only for internal use
1. Description of type
Type Features
MWGD 900.0 Combined microwave oven/cooker hoods with dual
microwave feed up to 900 watts, quartz grill and hot air
convection possible.
Rapid start, automatic defrosting, 201 stainless steel oven.
MWG 1000.0 Microwave with dual microwave feed up to 1000 watts,
quartz grill 900 watts, rapid start, automatic defrosting,
201 stainless steel oven cavity, turntable.
MW 900.0 Microwave with dual microwave feed up to 900 watts,
rapid start, automatic defrosting, 201 stainless steel oven
cavity with turntable and electronic clock.
MW 800.0 Microwave with feed up to 750 watts, 99 minutes 99
seconds timer, power control with 10 cooking modes,
4-step automatic programm control.

Service Manual MWG 1000 5
Only for internal use
Introduction
Every appliance is carefully tested before it leaves the factory. However it is important that it is
assembled and operated correctly.
Despite all safety measures, the safety of the appliance depends on it being correctly installed. It is
equally important for the user to operate the appliance correctly and to carry out the appropriate
maintenance measures.
It is extremely important for the owner to read through the operating instructions before using the
appliance for the first time to ensure that it is operated correctly, that it works safely and that good results
are obtained.
WARNING - MICROWAVE ENERGY
NOBODY SHOULD BE EXPOSED TO THE MICROWAVE ENERGY RADIATED BY
THE MAGNETRON, THE WAVEGUIDE OR THE ANTENNA IF THESE ARE
OPERATED INCORRECTLY OR HAVE BEEN IMPROPERLY CONNECTED. ALL
MICROWAVE TERMINALS FOR INPUT AND OUTPUT, THE WAVE GUIDE AND
ALL FLANGES AND SEALS MUST BE FASTENED AND SEALED CORRECTLY.
THE APPLIANCE MUST NEVER BE PUT INTO OPERATION WITHOUT THE OVEN
CONTAINING A LOAD THAT ABSORBS MICROWAVE ENERGY. NEVER LOOK
INTO AN OPEN WAVEGUIDE OR AN ANTENNA WHEN THE MAGNETRON IS
UNDER VOLTAGE. THE APPLIANCE MUST NEVER BE OPERATED WITHOUT
THE CASE EXCEPT WHEN IT IS BEING GIVEN A TRIAL RUN. IN THIS CASE,
HOWEVER, THE MAGNETRON AND THE VISIBLE MICROWAVE TERMINALS
MUST BE MEASURED FOR MICROWAVE LEAKAGE.
ATTENTION
The appliance must not be used under the following conditions:
- if the door does not close properly and does not fit the frame because it is distorted or because the
hinges have been damaged,
- if the door or the door seal are damaged,
- if the appliance shows obvious signs of damage,
- if the door does not close properly.
The appliance must not be used if any of the components of the door interlock system, the door or any
parts of the high-frequency circuit are damaged. These parts must be replaced.

6 Service Manual MWG 1000
Only for internal use
2. Repair and maintenance
IMPORTANT NOTES
All work and repairs on the components of microwave ovens may only be carried out
by a qualified service technician who has been trained by the manufacturer and
authorized to carry out such work.
Safety can be increased by using special tools such a TORX screwdriver and
measuring instruments to test microwave leakage.
In order to prevent accidents and damage to the appliance, the following rules should
be observed when carrying out repairs:
♦Before opening up the case disconnect the appliance from the mains or switch
off the main switch of the appliance. Wait at least 3 minutes.
♦Before beginning the work, the technician should take off his watch and, if
necessary, his metal bracelets. Never touch high-tension parts and wires.
♦Before checking or exchanging, discharge the high-voltage capacitor for the
appliance housing with an insulated conductor. Before shorting the capacitor
terminal make sure that the conductor to the housing has been earthed.
♦Do not use a usual voltmeter to measure the high tension.
The following points must be checked before the appliance is reconnected to the mains:
♦that all internal terminals have been properly connected;
♦that all wires are insulated and that they do not come into contact with the door
of the appliance, with the case or with any sharp edges;
♦that all grounding terminals are in perfect condition, electrically and
mechanically;
♦that no changes have been made to the built-in safety devices and that they are
not manipulated in any other way;
♦that all spare parts conform to the manufacturers specifications.

Service Manual MWG 1000 7
Only for internal use
2.1 Technical data MWGD 900.0
Technical requirements
Measured at an ambient temperature of 25°C.
Electrical system
All voltages are based on average values.
Nominal input voltage
207 - 244 V
Output
210 - 244 V
Test voltage (statutory requirement):
207 - 244 V
Electrical terminals (EN-335-1):
230 V
Frequency
50 Hz
Phases
Single-phase Operation
Nominal power input
Microwave 1500 W (short), 1400 W (long)
Grill 900 W
Crisp (Grill + MW) 2550 W
Cooker hood 355 W / 290 W (incandescent lamps / PL lamp)
In total 2850 W / 2775 W (cold operation), 2600 W / 2550 W (hot operation)
(incandescent lamps / PL lamp)

8 Service Manual MWG 1000
Only for internal use
Nominal power input
Microwave 7 A
Grill 4.2 A
Crisp 11 A
Crisp 10 A (CH / DK)
Cooker hood 2.3 A / 2.2 A (incandescent lamps / PL lamp)
In total 13 A / 12.5 A (cold operation), 11.7 / 11 A (hot operation)
(incandescent lamps / PL lamp)
Fuses
DE 16 AL
16 AH
Features of the microwave oven
Power output 850 W +10 % /- 50 W
(according to IEC 7051) (when the oven is empty)
Output regulated by ON / OFF switch
Duration of cycle 20.5 sec.
Power levels 8 (between 0 W and 850 W)
Features of the quartz grill
Power density 2.2 W / cm²
Grilling space 330 cm²
Heating uptime 30 sec.
Max. power input at 230 V 900 W
Features of the cooker hood in accordance with DIN 44971
Air suction (exhaust air) 360 m3/ hour
Air suction (recirculating air) 240 m3/ hour
Pressure 345 Pa
Timer
90 minutes
Oven lamp
Energy saver 1000 hours, 240 V max. 25 W, cannot be exchanged by customers.
Cooker hood lamp
Standard lamp 2 x 40 W 230/240V E14, can be exchanged by customers.

Service Manual MWG 1000 9
Only for internal use
Mechanics
Weight
Gross 40 kg
Net 36 kg
Dimensions
Outer dimensions 598 x 340 x 540 mm (W x H x D)
Gross dimensions of oven cavity 335 x 290 x 1 85mm (18.0 1)
Useable volume lEC 705 290²x PIE x 173
4
Fitting space dimensions
Visible parts 600 x 340 x 540 mm (W x H x D)
With exhaust part 600 x 340 x 540 mm (W x H x D)
Distance from hob at least 430 mm
Exhaust pipes 120 mm
Building-in kit 4-point holder System
Distance from wall adjustable from 0 - 40 mm, in steps of 5 mm
Load-bearing capacity at least 60 kg on holder system
The appliance can be built in without removing the decorative parts.
When the appliance is being serviced, it should be possible to remove the microwave unit and the fan
motor without dismounting the entire appliance.
Material of the oven cavity
Non-rust steel
Technical details
Noise level
MW 58 dBA (1 pW) IEC704
125 Hz max. 66 dB
250 Hz max. 62 dB
Cooker hood 68 dBA (exhaust air)
67 dBA (exhaust air)
In total 68 dBA (exhaust air)
67 dBA (exhaust air)
Hob lighting
Distance of 430 mm 290 / 315 lux (incandescent lamps / PL lamp)
Distance of 650 mm 230 / 240 lux (incandescent lamps / PL lamp)

10 Service Manual MWG 1000
Only for internal use
Microwave feed, turntable
The microwaves are fed into the oven in two
places. This novel system is known as Dual
Microwave Feed (DMF). The rotation of the
turntable ensures that the microwave energy
is evenly absorbed by the food. The turnta-
ble consists of a roller stay and a glass plate.
Grill (MWDG 900.0 and MWG 1000.0)
The grill element is a high-output quartz grill
consisting of two glass tubes connected in
a cascade. They are accommodated in a
special case mounted at the top of the oven
cavity. In order to make it impossible to
touch the glass tubes they have the
additional protection of an internal ceiling
which is welded to the inside of the oven.
The grill element cannot be cleaned inside
the oven.
Grill cannot be
folded down!

Service Manual MWG 1000 11
Only for internal use
2.2 New features
Crisp
A combination of
♦Grill
♦Microwave oven
♦Crisp plate special metal ovenware
(reaches 200°C within two minutes)
has been developed.
Ventilation and air flow

12 Service Manual MWG 1000
Only for internal use
2.3 Description of the components and their functions
Noise filter Prevents any interference from radio or television that may occur
when the appliance is being put into operation.
Fan motor The fan motor activates the fan which sucks in air through the vents
on the right side of the appliance and which causes it to circulate
around the magnetron and the transformer. Some of the air is
directed into the case in order to start the antenna turning and to
remove any excessive steam produced by the food. This steam is
blown towards the vents on the left and at the rear and is thus
extracted.
Oven lamp The oven lamp serves to control the food which can be seen through
the viewing panel in the door. The oven lamp is always switched off
when the cooking time has been set.
H.V. transformer The H.V. transformer serves to generate a filament voltage to heat
up the magnetron and to generate high voltage for the magnetron
tubes. During cooking the 220V ~ (240V) used for the primary
winding is converted into approx. 3.3V ~ on the filament winding and
into approx. 2300V ~ on the secondary high-voltage winding of the
power transformer.
Half-wave voltage- The half-wave voltage-doubling circuit consists of a regulator and a
doubling circuit capacitor with shunt resistance whose job it is to transform the
2300V ~ from the secondary winding of the high-voltage transformer
into approx. 4000 V= in order to operate the magnetron.
Magnetron tubes The magnetron generates microwaves using strong electric and
magnetic fields. The microwaves are conducted into the oven where
they are evenly distributed by the antenna to generate the required
heat in the food.
Monitor switch This switch is usually open. It is closed when the door is open.
Should door switch remain closed for any reason, the fuse will be
short circuited and will blow. The short-circuit current is limited by
resistor 3104/3105.
Latch switches These switches are safety switches which are activated by the door.
Switch 1040 interrupts the current to the electronic controls and the
display panel. Switch 1040 is the main door switch.
Note: Defective switches should be destroyed immediately to
prevent them from being used again.
Grill The grill (MGWD 900) cannot be pulled down to make it easier to
clean the inside of the oven. The heat emanating from the grill, or the
heating element, is so intense that the dirt is burned away.
Turntable motor The turntable motor is a small synchronous motor which drives the
turntable via a roller stay. The motor can start from any position.

Service Manual MWG 1000 13
Only for internal use
3. Repair and maintenance
IMPORTANT NOTES
All work and repairs on the components of microwave ovens may only be carried out
by a qualified service technician who has been trained by the manufacturer and
authorized to carry out such work.
Safety can be increased by using special tools such a TORX screwdriver and
measuring instruments to test microwave leakage.
In order to prevent accidents and damage to the appliance, the following rules should
be observed when carrying out repairs:
Before opening up the case disconnect the appliance from the mains or switch
off the main switch of the appliance.
The following points must be checked before the appliance is reconnected to the
mains:
♦that all internal terminals have been properly connected;
♦that all wires are insulated and that they do not come into contact with the door
of the appliance, with the case or with any sharp edges;
♦that all grounding terminals are in perfect condition, electrically and
mechanically;
♦that no changes have been made to the built-in safety devices and that they
are not manipulated in any other way;
♦that all spare parts conform to the manufacturers specifications.
WARNING: MICROWAVE ENERGY
NOBODY SHOULD BE EXPOSED TO THE MICROWAVE ENERGY RADIATED BY
THE MAGNETRON, THE WAVEGUIDE OR THE ANTENNA IF THESE ARE
OPERATED INCORRECTLY OR HAVE BEEN IMPROPERLY CONNECTED.
ALL MICROWAVE TERMINALS FOR INPUT AND OUTPUT, THE WAVE GUIDE
AND ALL FLANGES AND SEALS MUST BE FASTENED AND SEALED
CORRECTLY.
THE APPLIANCE MUST NEVER BE PUT INTO OPERATION WITHOUT THE OVEN
CONTAINING A LOAD THAT ABSORBS MICROWAVE ENERGY.
NEVER LOOK INTO AN OPEN WAVEGUIDE OR AN ANTENNA WHEN THE
MAGNETRON IS UNDER VOLTAGE.
THE APPLIANCE MUST NEVER BE PUT INTO OPERATION WITHOUT HOUSING.

14 Service Manual MWG 1000
Only for internal use
3.1 Dismantling of the cooker hood for repair work
As the appliance is very heavy (approx. 40 kg) it is not usually possible for one person to
dismount the appliance from the wall!
Connecting block / cooker hood motors
The connecting block and the cooker hood motors can be accessed from the top.
The wooden panel above the combination appliance might have to be removed for this purpose.
Motors
The fan motors of the cooker hood are accessible after the fascia (7 screws) has been removed.

Service Manual MWG 1000 15
Only for internal use
3.2 Microwave oven and cooker hood controls
In order to carry out repair work on the microwave oven and on the cooker hood controls, the microwave
oven must be removed from the cooker hood. This is possible with a combination appliance that is
mounted on the wall.
Removal: The parts can be dismantled in the following sequence:
1. Fat filters (A)
2. Unscrew the four Torx (B) screws from below. (The screws are visible after the fat filters have
been removed and the flat panel has been extended).
3. Air grating (C) at the top (2 screws).
4. Lift away the side panel on the left (D).
5. Open the connection box.
6. Pull away the connection leads for the microwave oven (F) and the cooker hood controls
(G) from the top of the connection block.
7. Take the microwave oven out of the cooker hood case.
8. The operation fascia (H) of the microwave oven can be detached by lifting it upwards. Then you
can access the switches of the cooker hood.

16 Service Manual MWG 1000
Only for internal use
3.3 Dismantling and assembling the appliance
Removing the case
CAUTION HIGH VOLTAGE!
Disconnect the appliance from the electricity
mains before removing the case.
After the case has been removed the parts that are
under high voltage are accessible and technical work
can be carried out on them.
Removing the operation fascia
Lift the operation fascia and remove it carefully.

Service Manual MWG 1000 17
Only for internal use
Exchanging the oven lamp
Exchanging the grill / heating element
Attention:
The ventilator must first be removed together with the
case before the grill or the heating element can be
exchanged.

18 Service Manual MWG 1000
Only for internal use
Exchanging the magnetron
Exchanging the door switch unit

Service Manual MWG 1000 19
Only for internal use
Exchanging the door
Exchanging the insulation for the air channel

20 Service Manual MWG 1000
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Mounting the transformer
Mounting the overheating protection