Merrychef s Parts Manual

1

402s Ovens Part. N

o.

32Z3539 Issue 4

402s

SERVICE& PARTS MANUAL

SERVICE MANUAL

CAUTION MICROWAVE EMISSIONS

DO NOT BECOME EXPOSED TO EMISSIONS FROM THE MICROWAVE

GENERATOR OR PARTS CONDUCTING MICROWAVE ENERGY

This manual covers UK/EC models manufactured from:
Version 2.0 Serial No. 000745 –001199
Version 3.0 Serial No. 001200 onwards

ISSUE 4

01.05.2008

Merr ychef

Version 3.0

Version 2.0

2

402s Ovens Part. N

o.

32Z3539 Issue 4

Safety code..............................................................................3

Product specifications..............................................................4

Installation instructions ............................................................5

Main features ...........................................................................6

Main features control panel Version 2.0 ..................................7

Main features control panel Version 3.0 ..................................8

Principal components: RHS.....................................................9

Principal components: LHS ...................................................10

Principal components: Control Box .......................................11

Principal components: Back View .........................................12

Principal components: Power Supply ....................................13

Principal components: Cavity Parts & KFC Accessories ......14

Principal components: External panels & Parts.....................15

Principal components: Electronic control panel assembly.....16

Parts matrix...................................................................... 17-18

Procedure for Power output measurement............................19

Procedures for Principal Component tests ..................... 20-21

Procedure for door interlock adjustment.......................... 22-23

Hot Air Motor and controller............................................. 24-25

Circuit Diagram ................................................................ 26-33

Troubleshooting Guide .................................................... 34-38

Appendix 1: Temperature Sensor resistance data ................39

Appendix 2: MenuKey download procedure V2.0 .................40

MenuKey download procedure V3.0 .................41

Appendix 3: Cool down & Cleaning Procedure ............... 42-44

Appendix 4: Recommended Spares List ...............................45

Appendix 5: PCB connection Points ................................ 46-47

Appendix 6: Firmware revision guide............................... 48-53

Appendix 7: Electrical Installation Guide ...............................54

TABLE OF CONTENTS

Merrychef Limited,
Station Road West,
Ash Vale, Aldershot
Hampshire GU12 5XA
United Kingdom
Tel: [phone] Fax: [phone]
Internet address: http://www.merrychef.com
E-mail: [e-mail] or [e-mail]

3

402s Ovens Part. N

o.

32Z3539 Issue 4

This manual is designed to assist engineers who have been on a recognised product familiarisation
and training course run by Merrychef. It has been prepared to offer technical guidance for the 402s
range of Ovens.

Please remember that it is wiser not to attempt a service task if you are unsure of being able to
complete it competently, quickly, and above all safely.

To avoid injury to yourself, and to protect the appliance from possible damage, please follow this
Safety Code when servicing these ovens.

Before attempting to repair the oven, check it for microwave emission using a calibrated
emission detector.

Check that the oven is not emitting microwaves, even when supposedly not in operation.

Check that the oven is not operating continuously, whether the display indicates cooking or
not.

Always discharge the HT capacitors before working on the oven using a suitably insulated
10 M: Resistor.

When testing the oven with covers off run for short periods of time only or magnetrons will
overheat and the display will show Error condition.

Before removing any covers from the oven, do all of the following.

x Switch off the mains supply and remove the plug from the wall socket.

or

x If the oven is hard wired, ensure that the power is turned off at the isolator switch.

Note:

The On/Off switch on the oven is not adequate protection against electric

shock, as it does not isolate all of the internal wiring from the mains.

Upon completion of a service the oven, or before reconnecting the appliance to the electrical
supply for testing, check all of the following points:

x All internal electrical connections are correct (see wiring diagram).
x All wiring insulation is correct and is not touching a sharp edge.
x All grounding connections are electrically and mechanically secure.
x All door safety interlocks are secure and mechanically sound.
x The door operation is smooth, and the arms run freely in the slots.
x The door activates all four of the door interlock switches and in the correct order
x The temperature sensor is correctly connected to the Power PCB.

Before finishing a service call, recheck the following points:

x All of the electronics are functioning correctly and all of the touch pads are working.
x Microwave emissions are below permissible limit of 5 mW/cm².
x The power output of the oven is checked in accordance with the procedure page.
x Oven has correct 50mm (2 inches) air gap all round and 50mm (2 inches) above.

Air flow should not be restricted.

SAFETY CODE

4

402s Ovens Part. N

o.

32Z3539 Issue 4

Power
Requirement

See Rating Label

Power Output Microwave 100%

Convection

1500watts
3250watts

External
Dimensions

Height

Width

Depth

595mm (23.0 inches)

585mm (23.0 inches)

700mm (27.5 inches)

Weight Nett 90kg ( 198lb.s )

Construction Cavity

Casework

304 Stainless Steel

PRODUCT SPECIFICATIONS

Supply

Voltage

Freq.

Hz

Phase/Supply

Control

Type

Type

Country
/Region

VVV F P C R TT ZZ

Voltage (ac)

208 = 208V
220 = 220-230V
240 = 230-240V

5 =

50Hz

6 =
60Hz

Phase Arrangement
A =
L + N + E (30 Amp)

B =
L1 + L2 + N + E

C =
2 P + Gnd (20 Amps)

D =
2 P + Gnd (30 Amps)

K =

Electronic
MenuKey

1

2
3

GM =

General
Market

UK =

United
Kingdom

US =

USA

EU =

Europe

Model Number: 402S VVV F P C R TT ZZ

Example 402S2205BK2GMEU

Model No. EC402s
220V, 50Hz, L1 +L2 +N +Earth supply, MenuKey Revision 1, General Market, EU

Version

Serial Number (Rating Plate):

Month 00/ Year 00/ Production number 00000

e.g 01 08 03349 Oven manufactured January, 2008, production number 03349

5

402s Ovens Part. N

o.

32Z3539 Issue 4

Installation Instructions for Mealstream 402s Ovens

Power Supply Requirements

The Mealstream 402s should be connected to a suitable electricity supply, which can cope with
the switching-on surge that occurs with certain types of catering equipment, including
microwaves. Because of this requirement, we strongly recommend that a separate, suitably
rated supply is installed for the oven.

The supply for the oven should be fitted with a Type "C" or Time Delay circuit breaker.

If the oven is hard-wired to the supply, a double-pole isolator switch with a contact gap of at
least 3mm ( 1/8 inch ) should be fitted.

Positioning the Oven

In order to maintain adequate ventilation for air intake
and exhaust, and to allow access for cleaning filters,
you must allow a minimum of 50 mm ( 2 inches )
clearance at the sides and rear of the oven.

Air intake temperature should not exceed 45°C (110°F )
excessive temperature will lead to reduced operating duty
cycle, or premature ageing of internal components.
Failure to comply with these conditions will invalidate the
warranty.

Note:
The minimum
recommended clearance
required for air flow

Grounding requirement

This appliance must be connected to a grounded, metallic, permanent wiring system, or an
equipment grounding conductor should be run with the circuit conductors and connected to the
equipment grounding terminal or lead on the appliance.

INSTALLATION INSTRUCTIONS

NEVER Install an oven above fryers,

grills, griddles or any other
major heat source.

ALWAYS Place containers in the cavity

carefully - impact damage
may chip the vitreous enamel
coating on the runners and
baffle plate.

Earth Bond terminal

An Earth Bond Terminal is provided on the rear panel of the oven for independent Earth (GND)
connection.

Stacking the oven ( Maximum one only)

Using stacking kit Part No. SA129

6

402s Ovens Part. N

o.

32Z3539 Issue 4

h

DOOR

The door consists of a thermally insulated inner
section, and an additional air gap provided by a
twin skinned door front to lower the surface
temperature.

i

DOOR SEAL

These ensure a tight seal around the door.
They should be kept clean and checked
regularly for signs of damage. Replace if worn
or damaged.

j

ELECTRICAL SUPPLY CORD

Electrical supply cord is situated on the rear of
the oven,

k

AIR FILTERS

Main intake for cooling air for internal
components. Must be clear of obstructions.

m

STEAM VENT PIPE

Vents steam from the oven cavity

L

IMPINGER PLATES ( Upper & Lower)

Direct the air in the cavity. They must be
cleaned on a regular basis, and kept free of
debris

MAIN FEATURES

k

h

d

i

j

a

On/Off SWITCH

This is used to turn the oven On or Off.

IT DOES NOT ISOLATE INTERNAL WIRING
FROM THE MAINS SUPPLY.

b

MenuKey

The MenuKey System automatically changes
all the cooking programs with an electronic key
and allows program names to be identified.

c

OVEN CAVITY

The oven cavity is mainly constructed from
stainless steel panels. It must be kept clean.

d

GREASE FILTER

The grease filter must be cleaned on a regular
basis, and kept free of debris.

e

RACK

The cooking rack should be removed daily and
cleaned

f

HOT AIR FAN

Situated behind the grease filter and circulates
the hot air through the cavity.

g

RATING PLATE

The rating plate is situated on the rear of the
oven, and states the Model, Serial Number,
Electrical Ratings and Manufacturers
telephone number.

e

L

f

b

g

k

c

a

L

m

7

402s Ovens Part. N

o.

32Z3539 Issue 4

Electronic control panel: Version 2.0

MAIN FEATURES

CANCEL PAD

Cancels all timed cooking cycles, pre-programmed
operations and stops the microwave energy. It does
not alter the oven temperature. If the oven is hot,
food will continue to cook and should be removed
from the oven immediately. This pad will also cancel
any incorrect operations. It will not erase programs.

FAN SPEED PADS

The Fan speed can be increased and decreased in
5% steps ( 10% to 100% )

FUNCTION PADS

Move through control functions in the Main Display

MAIN DISPLAY PANEL

Shows the principal functions of the oven.
When cooking, the time remaining counts down.
Also displays error messages and oven temperature.
(See TROUBLESHOOTING )
When storing and recalling a program the display
indicates the program number and details

POWER PADS

FAN SPEED PADS

CANCEL
PAD

MAIN DISPLAY
PANEL

MenuKey

PROGRAM

TIME/ PROGRAM PADS

PREHEAT/ COOL DOWN

FUNCTION
PADS

START

MenuKey

The MenuKey System automatically changes all the
cooking programs with an electronic key and allows
program names to be identified.

POWER PADS

The microwave power can be increased or
decreased adjusted in 10% steps. ( 0% to 100% )
The default setting is 50% microwave power.

PREHEAT/ COOL DOWN

Commences main oven heating cycle to a preset
temperature. Press and hold for 5 seconds to
commence cool down procedure ( See CLEANING )

PROGRAM

Activates program mode for storing programs in
memory START PAD Commences a program

TIME/ PROGRAM PADS

These pads are used for setting the cooking time in
1 second steps to a maximum of 10 minutes.

They are also used for storing and recalling
programs from 0-499

Message Condition Possible cause

ERROR MAGNETRON 1 Magnetron 1 has overheated Blocked Air filter(s)

Oven located near hot air sources
Oven being used empty
Cooling fan failure
Magnetron failure

ERROR MAGNETRON 2 Magnetron 2 has overheated

ERROR MAGNETRON 1 & 2 Magnetron 1 and 2 have overheated

CAVITY SENSOR ERROR Cavity temperature exceeds more

than 50°C above PREHEAT
temperature setting during cook cycle

Indicates combustion ( fire ) in oven cavity
Note: In service operations when
PREHEAT is set to 0°C this message can
appear when the oven is operated

Display Panel error messages

8

402s Ovens Part. N

o.

32Z3539 Issue 4

Electronic control panel: Version 3.0

MAIN FEATURES

CANCEL
PAD

MAIN DISPLAY
PANEL

MenuKey

COOL DOWN

FUNCTION
PADS

FUNCTION
PADS

FUNCTION
PADS

MenuKey 2

The MenuKey System automatically changes all the
cooking programs with an electronic key and allows
program names to be identified

CANCEL PAD

Cancels all timed cooking cycles, pre-programmed
operations and stops the microwave energy. It does
not alter the oven temperature. If the oven is hot, food
will continue to cook and should be removed from the
oven immediately. This pad will also cancel any
incorrect operations. It will not erase programs.

DISPLAY PANEL

Shows the principal functions of the oven.
When cooking, the time remaining counts down.
Also displays error messages and oven
temperature. When storing and recalling a
program the display indicates the program
number and details.

FUNCTION PADS

The function pads select options shown in the
DISPLAY PANEL.

COOL DOWN PAD

Puts the oven into Cool Down Mode prior to
cleaning

Display Panel error messages

Error Message Condition Possible Cause

Magnetron 1 Overheat
Ensure air filters are clean
Allow oven to cool

Magnetron 1 has overheated Blocked air filters

Oven located near hot air source
Oven being used empty
Cooling fan failure
Magnetron failure

Magnetron 2 Overheat
Ensure air filters are clean
Allow oven to cool

Magnetron 2 has overheated

Magnetron 1 & 2 Overheat
Ensure air filters are clean
Allow oven to cool

Magnetron 1 & 2 have overheated

Magnetron 1 Failure Magnetron 1 no microwave output

Magnetron 2 Failure Magnetron 2 no microwave output

Magnetron 1 & 2 Failure Magnetron 1 & 2 no microwave

output

Ambient Overheat
Ensure air filters are clean
Allow oven to cool

Temperature inside casing has
exceeded limit

Blocked air filters
Restricted airflow to air filters
Oven located near hot air source
Circulation fan failure
Combustion (fire) in cavity

Cavity Overheat
Please contact service

Cavity temperature has exceeded
more than 295°C

Blocked air filters
Restricted airflow to air filters
Combustion (fire) in cavity

Heater Failure Cavity has not reached a

temperature of 100°C in 10 minutes

One or more heater elements have failed
and need to be replaced

Check power supply
Magnetron failure

9

402s Ovens Part. N

o.

32Z3539 Issue 4

PRINCIPAL COMPONENTS: Right Side

No. Description Part No.

1 Cavity Overheat stat 30Z1024

2 Motor Start Capacitor 2µF ( Blue ) 30Z1298

3 Filter 16A (Threaded) 30Z1340

4 Air filter SA276

5 Stirrer motor Assembly SA288

6 Microswitch SW1

Microswitch SW2

30Z1294

7 Door Hinge Assembly RH SA202

8 Magnetron Cooling Fan 30Z1295

26 HV Capacitor 2500V 1.1ȝF ( 50HZ models ) 30Z1242

26 HV Capacitor 2500V 0.88ȝF ( 60HZ models ) 30Z1251

26A HV Capacitor universal clip 31Z1261

70 Fibre Optic PCB 11M0364

71 Solid State Relay 30Z1362

1

3

4

5

6

7

8

26

6

26A

2

70

71

10

402s Ovens Part. N

o.

32Z3539 Issue 4

PRINCIPAL COMPONENTS: Left Side

No. Description Part No.

3 Filter 16A (Threaded) 30Z1340

4 Air filter SA276

5 Stirrer motor Assembly SA288

6 Microswitch SW3

Microswitch SW4

30Z1294

9 Door Hinge Assembly LH SA203

10 Motor Controller 30Z1319

24 Thermistor Cavity 30Z1315

25 HV Capacitor 2500V 1.0ȝF ( 50Hz models ) 30Z1331

25 HV Capacitor 2500V 0.88ȝF ( 60Hz models ) 30Z1251

25A HV Capacitor clip 31Z1261

70 Fibre Optic PCB 11M0364

3

25

25A

5

6

9

10

4

6

70

24

11

402s Ovens Part. N

o.

32Z3539 Issue 4

PRINCIPAL COMPONENTS: Control Box

No. Description Part No.

11 Fuse 10A HRC 30Z0217

12 Gold resistor ( 220R ) 30Z0235

13 Relay PCB Assembly 11K0004

14 Ribbon Cable 15way 11Z0298

15 Ribbon Cable 10way MenuKey 11M0117

16 Logic PCB Assembly Version 2.0 11K0002

16 Logic PCB Assembly Version 3.0 11K0012

17 Transformer LT (Low voltage) 30Z1155

18 Fuse 1A 30Z0957

59 Sounder SA257

72 Fibre Optic Logic PCB 11K0013

11

13

12

14

15

18

17

16

See

Principal

components:

POWER

SUPPLY

11

59

72

12

402s Ovens Part. N

o.

32Z3539 Issue 4

PRINCIPAL COMPONENTS: Back view

No. Description Part No.

20

Heater Element 220V 650W

DV0606

20

Heater Element 240V 650W

DV0607

21 Magnetron (Toshiba) 30Z1349

22 Magnetron Thermistor Assembly SA234

23 Convection ( Hot Air ) Motor Assembly SA208

27

Transformer 208/220/240V 50Hz

30Z1233

27

Transformer 208/220/240V 60Hz

30Z1230

28 HT Diode Assy PCB (Fibre Optic) 11H0364

28A HT Diode Assembly ( Non-optic) 11H0010

73 Magnetron Cooling Duct LH DV0039

74 Magnetron Cooling Duct RH DV0040

21

23

20

27

21

22

22

28A

27

28

74

73

13

402s Ovens Part. N

o.

32Z3539 Issue 4

PRINCIPAL COMPONENTS: Power Supply

N1 L1 L2

Electrical Supply: Twin phase
2P+N+Earth

No. Description Part No.

3 Filter 16A 30Z1340

11 Fuse 10A HRC 30Z0217

19

Cable Gland 31Z0500

Cable Gland Nut 31Z0499

29 Electrical Supply Lead Assembly Single Phase SA226

30 Terminal Block 31Z0447

31 Fuse 20A FLM 30Z1177

32 Fuse Holder 30A 30Z1178

34 Fuse Holder 10A 30Z0231

29A Electrical Supply Lead Assembly Twin Phase SA225

29A

Electrical Supply: Single Phase

19

29

30

3

31

11

32

34

29

29A

14

402s Ovens Part. N

o.

32Z3539 Issue 4

PRINCIPAL COMPONENTS

No. Description Part No.

5A Stirrer (behind stirrer glass) SA291

35* Grease Filter ( 2 parts ) SA340

SA339

36 Stirrer Glass DV0492

37* Rack Support ( Not shown ) DV0114

38 Upper Impinger plate SA211

39 Rack DV0275

40 Lower Impinger plate SA266

No. Description Part No.

60 Cool-down pan 32Z4028

61 Oven tray MC3175

62 Handle Assembly SA267

64 Griddle carrier SA350

65 Chicken Griddle (SA350 + DV0221 + DV0267) SA133

63 Griddle DV0221

KFC Accessories

60

61

62

63

64

65 Chicken Griddle SA133

* Parts 35 & 37 Contact Service Department

Cavity

35

36

38

36

39

40

5A

Stirrer glass
Shown removed

15

402s Ovens Part. N

o.

32Z3539 Issue 4

External Parts

PRINCIPAL COMPONENTS

No. Description Part No.

4 Air Filter SA276

41 Top Panel DV0187

42 Rear Panel SA329

43 Side Panel LH DV0091

45 Door Skin DV0501

46 Door Handle 32Z1066

47 Door Inner SA331

48 Door Choke DV0168

Door Seal (wide) DV0305

Door seal sealant ( tube ) 31Z0186

50 Bottom Trim DV0037

51 Side Panel RH DV0092

52 Door Assembly SA111

49

Control Panel

See page 16

52

51

50

41

48

4

42

43

4

49

47

Door Assembly

45

46

52

16

402s Ovens Part. N

o.

32Z3539 Issue 4

Electronic Control Panel Assembly

PRINCIPAL COMPONENTS

No. Description Part No.

53 MenuKey Dust Cover DV0052

54 Power switch (On/Off) 30Z1318

55 GM Membrane Version 2.0 DV0055

57 Display Assembly & Header Version 2.0 30Z1299

68 Display Assembly & Header Version 3.0 30Z1324

56 Front Panel Version 2.0 DV0036

58 MenuKey Socket 11K0005

66 GM Membrane Version 3.0 DV0254

67 Front Panel Version 3.0 DV0249

53

54

Version 2.0

58

57

56

53

54

58

68

67

Version 3.0

66

55

17

402s Ovens Part. N

o.

32Z3539 Issue 4

Ref. No. Description Part No.

1 Cavity High limit Stat 30Z1024

2 Motor Start Capacitor 2µF ( Blue ) 30Z1298

3 Filter 16A 30Z1340

4 Air filter SA276

5 Stirrer motor Assembly SA288

5A Stirrer (inside cavity) SA291

6 Microswitch SW1, SW2, SW3, SW4 30Z1294

7 Door Hinge Assembly RH SA202

8 Magnetron Cooling Fan 30Z1295

9 Door Hinge Assembly LH SA203

10 Motor Controller 30Z1319

11 Fuse 10A HRC 30Z0217

12 Gold resistor ( 220R ) 30Z0235

13 Relay PCB Assembly 11K0004

14 Ribbon Cable 15way 11Z0298

15 Ribbon Cable 10way MenuKey 11M0117

16 Logic PCB Version 2.0/ 2.5 11K0002

16 Logic PCB Assembly Version 3.0 11K0012

17 Transformer LT (Low voltage) 30Z1155

18 Fuse 1A 30Z0957

19 Cable Gland 31Z0500

Cable Gland Nut 31Z0499

20

Heater Element 220V 650W

DV0606

Heater Element 240V 650W

DV0607

21 Magnetron (Toshiba)

30Z1349

22 Magnetron Thermistor Assembly

SA234

23 Convection ( Hot Air ) Motor Assembly

SA208

24 Thermistor Cavity

30Z1315

25

HV Capacitor 2500V 1.0ȝF ( 50Hz Models)

30Z1331

25

HV Capacitor 2500V 0.88ȝF ( 60Hz Models )

30Z1251

25A HV Capacitor clip universal

31Z1261

26

HV Capacitor 2500V 1.1ȝF (50Hz Models)

30Z1242

26A HV Capacitor clip universal

31Z1261

27

Transformer 208/220/240V 50Hz

30Z1233

27

Transformer 208/220/240V 60Hz

30Z1230

28 HT Diode Assy

11H0010

29 Electrical Supply Lead Assembly

SA226

29A Electrical Supply Lead Assembly Twin Phase

SA225

30 Terminal Block

31Z0447

31 Fuse 20A FLM

30Z1177

Part number identification chart 1