Merrychef EC402S Parts List

Version 3.0

Version 2.0

EC402s

US Models including WAWA

SERVICE& PARTS MANUAL

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

CAUTION MICROWAVE EMISSIONS

DO NOT BECOME EXPOSED TO EMISSIONS FROM THE MICROWAVE

GENERATOR OR PARTS CONDUCTING MICROWAVE ENERGY

402s Ovens Pt. No. 32Z3522 Issue 5

1

ISSUE 5

23.02.2008

SERVICE MANUAL

TABLE OF CONTENTS

Microwave safety precautions .................................................3

Safety code..............................................................................4

Product specifications..............................................................5

Installation instructions ............................................................6

Main features ......................................................................7– 9

Principal components: RHS ...................................................10

Principal components: LHS ...................................................11

Principal components: Top ....................................................12

Principal components: Back View..........................................13

Principal components: Power Supply ....................................14

Principal components: Cavity Parts.......................................15

Principal components: External Panels .................................16

Principal components: Control Panel.....................................17

Parts Matrix...................................................................... 18-19

Procedure for Microwave Emission test .......................... 20-21

Procedure for Power output measurement............................22

Procedures for Principal Component tests ..................... 23-24

Procedure for door interlock adjustment.......................... 25-26

Hot Air Motor and controller............................................. 27-28

Wiring Diagrams ....................................................................29

Trouble Shooting Guide................................................... 30-34

Appendix 1: Temperature Probe............................................35

Appendix 2: MenuKey Procedures .................................. 36-37

Appendix 3: Cleaning Procedure ..................................... 38-40

Appendix 4: Recommended Spares List ...............................41

Appendix 5: PCB connection Points ................................ 42-43

Appendix 6: Engineering Test Settings..................................44

Merrychef USA

1111 North Hadley RD Fort Wayne IN 46804

Phone: 877/404 - 6872 Fax: 800/285 - 9511 e-mail: info@merrychefusa.com

402s Ovens Pt. No. 32Z3522 Issue 5

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MICROWAVE SAFETY PRECAUTIONS

CAUTION

WARNING TO SERVICE TECHNICIANS

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING

SERVICING TO AVOID POSSIBLE EXPOSURE TO

EXCESSIVE MICROWAVE ENERGY

(a) Do not operate or allow the oven to be operated with the door open.

(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make repairs as necessary:

1) interlock operation.

2) proper door closing.

3) seal and sealing surfaces (arcing, wear, and other damage).

4) damage to or loosening of hinges and latches.

5) evidence of dropping or abuse.

(c) Before turning on microwave power for any service test or inspection

within the microwave generating compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment, integrity and connections.

(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave generation and transmission systems shall be repaired, replaced, or adjusted by procedures described in this manual before the oven is released to the owner.

(i) For U.S.A.

(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner.

(e)

(ii) For CANADA.

A microwave leakage check to verify compliance with the Canadian Regulation, HEALTH AND WELFARE, SOR/79 920 should be performed on each oven prior to release to the owner.

402s Ovens Pt. No. 32Z3522 Issue 5

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SAFETY CODE

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 MΩ 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.

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

or

• 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:

• All internal electrical connections are correct (see wiring diagrams).

• All wiring insulation is correct and is not touching a sharp edge.

• All grounding connections are electrically and mechanically secure.

• All door safety interlocks are secure and mechanically sound.

• The door operation is smooth, and the arms run freely in the slots.

• The door activates all four of the door interlock switches and in the correct order

• The temperature sensor is correctly connected to the Power PCB.

Before finishing a service call, recheck the following points:

• All of the electronics are functioning correctly and all of the touch pads are working.

• Microwave emissions are below permissible limit of 4 mW/cm².

• The power output of the oven is checked in accordance with the procedure page.

• Oven has correct 2 inch ( 50mm ) air gap all round and 2 inches ( 50mm ) above.

Air flow should not be restricted.

402s Ovens Pt. No. 32Z3522 Issue 5

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PRODUCT SPECIFICATIONS

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

Example 402S2086DK3GMUS

Model No. EC402s 208V, 60Hz, 2P + GND supply, MenuKey Revision 3, General Market, USA

Supply

Voltage

Freq.

Hz

Phase/Supply

Control

Type

Rev Type

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)

K =

Electronic MenuKey

1

2 3

GM =

General Market

D = 2 P + Gnd (30 Amps)

Power Requirements

208Volts 240Volts

Power Output Microwave 100%

Convection

208V ac 60Hz 30Amp 2P & G 240V ac 60Hz 40Amp 2P & G

1500watts 3250watts

Country /Region

US =

USA

External Dimensions

Height

Width

Depth

Weight Nett

Construction Cavity

Casework

402s Ovens Pt. No. 32Z3522 Issue 5

23.0 inches

27.5 inches

198lb.s ( 90kg )

304 Stainless Steel

5

INSTALLATION INSTRUCTIONS

Installation Instructions for Mealstream Combination Ovens

Power Supply Requirements

The Mealstream Series 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 1/8 inch ( 3 mm ) should be fitted.

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.

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 2 inches ( 50 mm ) clearance at the sides and rear of the oven.

Air intake temperature should not exceed 110°F/45°C 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.

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.

Note: The minimum recommended clearance required for air flow

402s Ovens Pt. No. 32Z3522 Issue 5

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MAIN FEATURES

a

c

k

On/Off SWITCH

a

This is used to turn the oven On or Off.

IT DOES NOT ISOLATE INTERNAL WIRING FROM THE MAINS SUPPLY.

MenuKey

b

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

OVEN CAVITY

c

The oven cavity is mainly constructed from

stainless steel panels. It must be kept clean.

GREASE FILTER

d

The grease filter must be cleaned on a regular

basis, and kept free of debris.

RACK

e

The cooking rack should be removed daily and

cleaned

HOT AIR FAN

f

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

RATING PLATE

g

The rating plate is situated on the rear of the

oven, and states the Model, Serial Number, Electrical Ratings and Manufacturers telephone number.

m

b

L

d

f

e

L

DOOR

h

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.

DOOR SEAL

i

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.

ELECTRICAL SUPPLY CORD

j

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

AIR FILTERS

k

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

IMPINGER PLATES ( Upper & Lower)

L

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

STEAM VENT PIPE

m

j

i

h

k

Vents steam from the oven cavity

g

402s Ovens Pt. No. 32Z3522 Issue 5

7

MAIN FEATURES

Electronic control panel: Version 2.0

PREHEAT/ COOL DOWN

PROGRAM

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

TIME/ PROGRAM PADS

FAN SPEED PADS

MAIN DISPLAY PANEL

POWER PADS

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

FUNCTION PADS

START

CANCEL PAD

MenuKey

Display Panel error messages

Message Condition Possible cause

ERROR MAGNETRON 1

ERROR MAGNETRON 2

ERROR MAGNETRON 1 & 2

CAVITY SENSOR ERROR

Magnetron 1 has overheated

Magnetron 2 has overheated

Magnetron 1 and 2 have overheated

Cavity temperature exceeds more than 90°F above PREHEAT temperature setting during cook cycle

402s Ovens Pt. No. 32Z3522 Issue 5

8

Blocked Air filter(s) Oven located near hot air sources Oven being used empty Cooling fan failure Magnetron failure

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

MAIN FEATURES

Electronic control panel: Version 3.0

COOL DOWN

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.

FUNCTION PADS

MAIN DISPLAY PANEL

FUNCTION

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

PADS

CANCEL PAD

MenuKey

Error Message Condition Possible Cause

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

Magnetron 2 Overheat Ensure air filters are clean

Magnetron 1 has overheated

Magnetron 2 has overheated

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

Allow oven to cool

Magnetron 1 & 2 Overheat Ensure air filters are clean

Magnetron 1 & 2 have overheated

Allow oven to cool

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 565°F

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

Heater Failure Cavity has not reached a

temperature of 100°F in 10 minutes

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

402s Ovens Pt. No. 32Z3522 Issue 5

9

PRINCIPAL COMPONENTS: Right Side

5

6

7

8

4

1

2

3

26A

26

No. Description Part No.

1 Cavity High limit Stat 30Z1024

2 Motor Start Capacitor 2µF ( Blue ) 30Z1298

3 Filter 16A 30Z1339

4 Air filter SA276

5 Stirrer motor Assembly SA238

5A Stirrer (inside cavity) SA213

6 Microswitch SW1

Microswitch SW2

7 Door Hinge Assembly RH SA202

8 Magnetron Cooling Fan 30Z1295

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

26A HV Capacitor clip (0.88μF) 88mm 31Z0521

30Z1294

402s Ovens Pt. No. 32Z3522 Issue 5

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PRINCIPAL COMPONENTS: Left Side

3

5

5A

6

9

25A

25

No. Description Part No.

3 Filter 16A 30Z1339

4 Air filter SA302

5 Stirrer motor Assembly SA238

5A Stirrer (inside cavity) SA213

6 Microswitch SW3

Microswitch SW4

9 Door Hinge Assembly LH SA203

10 Motor Controller 30Z1293

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

30Z1294

10

4

25A HV Capacitor clip (0.88μF) 88mm 31Z0521

402s Ovens Pt. No. 32Z3522 Issue 5

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PRINCIPAL COMPONENTS: Control Box

See

Principal

components:

POWER

SUPPLY

11

16

17

18

12

13

14

15

59

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 SA231

16 Logic PCB Assembly Version 3.0 SA260

17 Transformer LT (Low voltage) 30Z1155

18 Fuse 1A 30Z0957

59 Sounder SA257

402s Ovens Pt. No. 32Z3522 Issue 5

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PRINCIPAL COMPONENTS: Back view

19

20

22

21

28

27

No. Description Part No.

19

20

Cable Gland 31Z0500

Cable Gland Nut 31Z0499

Heater Element 208V 650W

DV0576

21

23

24

20

28

27

22

20

21 Magnetron 30Z1171

22 Magnetron Thermistor Assembly SA234

23 Convection ( Hot Air ) Motor Assembly SA208

24 Thermistor Cavity 30Z1315

27 Transformer 208/220/240V 60Hz 30Z1230

28 HT Rectifier 11H0010

Heater Element 220V 650W

Heater Element 240V 650W

402s Ovens Pt. No. 32Z3522 Issue 5

DV0606

DV0607

13

PRINCIPAL COMPONENTS: Power Supply

3

31

19

29

32

11

34

30

No. Description Part No.

3 Filter 16A 30Z1339

11 Fuse 10A HRC 30Z0217

19 Cable Gland 31Z0500

19 Cable Gland Nut 31Z0499

29 Electrical Supply Lead Assembly SA217

30 Terminal Block 31Z0447

31 Fuse 20A FLM 30Z1177

32 Fuse Holder 30A 30Z1178

34 Fuse Holder 10A 30Z0231

402s Ovens Pt. No. 32Z3522 Issue 5

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