Viking Vmor-dmor205 Owner's Manual

SERVICE MANUAL

VMOR205SS DMOR205SS

S95M255VMO205

DMOR205SS

OVER THE RANGE

MICROWAVE OVEN

MODELS DMOR205SS

VMOR205SS

In the interest of user-safety, the oven should be restored to its original condition and only parts identical to those specified should be used.

WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock. (High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..)

TABLE OF CONTENTS

Page PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO

AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ................... INSIDE FRONT COVER

BEFORE SERVICING ...................................................................................................... INSIDE FRONT COVER

MICROWAVE MEASUREMENT PROCEDURE ..................................................................................................... 2

WARNING TO SERVICE PERSONNEL ................................................................................................................4

FOREWORD AND WARNING ................................................................................................................................5

PRODUCT SPECIFICATIONS ............................................................................................................................... 6

GENERAL INFORMATION ...................................................................................................................................6

OPERATION .........................................................................................................................................................9

TROUBLESHOOTING GUIDE ... ......... .................................................................................................................17

TEST PROCEDURE ............................................................................................................................................20

TOUCH CONTROL PANEL ASSEMBLY .............................................................................................................31

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE .................................................................. 37

PICTORIAL DIAGRAM ........................................................................................................................................ 46

LSI UNIT CIRCUIT ...............................................................................................................................................47

PRINTED WIRING BOARD ................................................................................................................................. 48

PARTS LIST ........................................................................................................................................................ 49

PACKING AND ACCESSORIES ......................................................................................................................... 54

This document has been published

Range Corporation

111 Front St., Greenwood, MS 38930

to be used for after sales service only. The contents are subject to change without notice

Tel: (888) 845-4641

VMOR205SS DMOR205SS

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.

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.

(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.

BEFORE SERVICING

Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the specified limit, contact Viking Service immediately @ 1-888-845-4641.

If the unit operates with the door open, service person should (1) tell the user not to operate the oven and (2) contact VIKING, plus the Department Of Health, Canada and/or the Food and Drug Administration's Center for Devices and Radiological Health immediately.

Service personnel should inform VIKING of any certified unit found with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit until the oven has been brought into compliance.

DANGER CAUTION

HIGH VOLTAGE

Do not energize a microwave oven with the outer case cabinet removed, because a microwave oven generates High Voltage in the circuit.

If you intend to operate the oven employing the high frequency switching power converter circuit, you should take special precautions to avoid an electrical shock hazard.

The high voltage transformer, high voltage capacitor and high voltage diode have energized high voltage potential approx. 8 KV.

The aluminium heat sink is connected to the switching power transistor Collector pole, and has an energized high voltage potential approx. 650V peak.

DO NOT ACCESS THE HIGH VOLTAGE TRANSFORMER, HIGH VOLTAGE CAPACITOR, HIGH VOLTAGE DIODE AND HEAT SINK WHEN THE POWER SUPPLY IS CONNECTED TO AN ELECTRICAL OUTLET.

Notes

VMOR205SS DMOR205SS

MICROWAVE MEASUREMENT PROCEDURE (USA)

A. Requirements:

1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm surface of the oven.

2) Safety interlock switches Primary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission in excess of 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

B. Preparation for testing: Before beginning the actual measurement of leakage, proceed as follows:

1) Make sure that the actual instrument is operating normally as specified in its instruction booklet.

Important: Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.

2) Place the oven tray in the oven cavity.

3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5½C (68½F) in the center of the oven cavity.

The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.) and made of an electrically nonconductive material such as glass or plastic. The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage is measured accurately.

4) Set the cooking control on Full Power Cooking Mode

5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed,

replace it with 275 ml of cool water.

at any point 5cm or more from the external

C. Leakage test:

Closed-door leakage test (microwave measurement)

1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.

2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on the meter.

3) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal has been breached (eg., around the switches, indicator, and vents). While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the closed latch assembly.

4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2, and that the secondary interlock switch does turn the oven OFF before any door movement.

NOTE: After servicing, record data on service invoice and microwave leakage report.

VMOR205SS DMOR205SS

MICROWAVE MEASUREMENT PROCEDURE (CANADA)

After adjustment of the door switches are completed individually or collectively, switch test and microwave leakage test must be performed with survey instrument and test result must be confirmed to meet the requirement of the performance standard for microwave ovens as undermentioned.

A. Requirements:

Every microwave oven shall function in such a manner that when the oven is fully assembled and operating with it's service controls and user controls adjusted to yield the maximum output, the leakage radiation, at all points at least 5 cm. from the external surface of the oven, does not exceed:

1) 1.0mW/cm2 with the test load of 275 ± 15 ml of water at an initial temperature 20 ±5oC.

2) 5.0mW/cm

3) 5.0mW/cm

when the outer enclosure is removed with a test load of 275 ± 15 ml of water at an initial temperature 20±5oC.

without a test load.

B. Preparation for testing: Before beginning the actual measurement of leakage, proceed as follows:

1) Make sure that the actual instrument is operating normally as specified in its instruction booklet. Important: Survey instruments that comply with the requirement for instrumentation as prescribed by CSA and NHW performance standard for microwave ovens must be used for testing recommended instruments are , NARDA 8100 and NARDA 8200.

2) Place the oven tray in the oven cavity.

3) Place the load of 275±15 ml of tap water initially at 20±5oC in the center of the oven cavity. The water container shall be a low form of 600 ml beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.) and made of an electrically nonconductive material such as glass or plastic. The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage is measured accurately.

4) Set the cooking control on Full Power Cooking Mode, Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed, replace it with 275 ml of cool water.

C. Leakage test with enclosure installed :

1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.

2) Move the probe slowly, not faster than 2.5 cm/sec. along the gap, watching for the maximum indication on the meter.

C. Leakage test without enclosure:

1) Remove the enclosure (cabinet).

2) Grasp the probe of the survey instrument and hold it perpendicular to all mechanical and electric parts of the oven that is accessible to the user of the oven including, but not limited to, the waveguide, cavity seams, magnetron gap between the door and the body of the oven.

3) Move the probe slowly, not faster than 2.5 cm/sec. along the gap, watching for the maximum indication on the meter.

4) Measure carefully at the point of highest leakage and make sure that the highest leakage is under 5mW/cm2.

CAUTION: Special attention should be given to avoid electrical shock because HIGH VOLTAGE is generated during this test

No Load test

1) Operate the oven without a load and measure the leakage by the same method as the above test procedure " Leakage test with enclosure installed"

2. Make sure that the highest leakage should not exceed 5mW/cm2.

NOTE: After servicing, record data on service invoice and microwave leakage report.

VMOR205SS

DMOR205SS

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts fatal, electrical shock.

(Example) High Voltage Capacitor, High Voltage Power Trans-

former, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..

Read the Service Manual carefully and follow all instructions.

may result in a severe, possibly

Don't Touch ! Danger High Voltag

Before Servicing

1. Disconnect the power supply cord , and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

WARNING: RISK OF ELECTRIC SHOCK.

DISCHARGE THE HIGH-VOLTAGE CAPACITOR BEFORE SERVICING.

The high-voltage capacitor remains charged about 60 seconds after the oven has been switched off. Wait for 60 seconds and then short-circuit the connection of the highvoltage capacitor (that is the connecting lead of the highvoltage rectifier) against the chassis with the use of an insulated screwdriver.

Whenever troubleshooting is performed the power supply must be disconnected. It may in, some cases, be necessary to connect the power supply after the outer case has been removed, in this event,

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power transformer.

5. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.

6. After that procedure, reconnect the power supply cord.

When the testing is completed,

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Reconnect the leads to the primary of the power transformer.

5. Reinstall the outer case (cabinet).

6. Reconnect the power supply cord after the outer case is installed.

7. Run the oven and check all functions.

After repairing

1. Reconnect all leads removed from components during testing.

2. Reinstall the outer case (cabinet).

3. Reconnect the power supply cord after the outer case is installed.

4. Run the oven and check all functions.

Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven turntable, close the door and set the power to HIGH and set the microwave timer for two (2) minutes. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out Before Servicing procedure and re-examine the connections to the component being tested.

When all service work is completed and the oven is fully assembled, the microwave power output should be checked and microwave leakage test should be carried out.

SERVICE MANUAL

VIKING RANGE CORPORATION

MICROWAVE OVENS

PRODUCT DESCRIPTION

VMOR205SS DMOR205SS

FOREWORD

This Manual has been prepared to provide Viking Service Personnel with Operation and Service Information for the VIKING MICROWAVE OVENS, VMOR205SS and DMOR205SS.

It is recommended that service personnel carefully study the entire text of this manual and the base model's manual so that they will be qualified to render satisfactory customer service.

Check the interlock switches and the door seal carefully. Special attention should be given to avoid electrical shock and microwave radiation hazard.

WARNING

Never operate the oven until the following points are ensured: (A) The door is tightly closed. (B) The door brackets and hinges are not defective. (C) The door packing is not damaged. (D) The door is not deformed or warped. (E) There is no other visible damage with the oven.

Servicing and repair work must be carried out only by trained service personnel.

DANGER

Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing. Service personnel - Do not contact the following parts while the appliance is energized; High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness; If provided, Vent Hood, Fan assembly, Cooling Fan Motor.

GENERAL INFORMATION

OPERATION

TROUBLESHOOTING GUIDE AND TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WIRING DIAGRAM

PARTS LIST

All the parts marked “*” on parts list are used at voltages more than 250V.

Removal of the outer wrap gives access to voltage above 250V.

VIKING RANGE CORPORATION

111 Front St., Greenwood, MS 38930

Tel: (888) 845-4641

VMOR205SS DMOR205SS

SPECIFICATION

ITEM DESCRIPTION

Power Requirements

Power Output 850 watts (IEC-705 TEST PROCEDURE)

Convection Power Output 1400 watts

Case Dimensions Width 29-15/16"

Cooking Cavity Dimensions Width 17-1/8"

1.1 Cubic Feet Depth 13-13/16"

Hood lamps (2) 1 bulb @ 20W & 1 bulb @ 40W

Hood fan Horizontal discharge 230 C.F.M. , Vertical discharge 240 C.F.M. ,

Control Complement Touch Control System

120 Volts / 13.2 Amperes (Microwave), 13.2 Amperes (Convection) - [UL Rating] 116 Volts / 13.2 Amperes (Microwave), 13.2 Amperes (Convection) - [CSA Rating] 60 Hertz Single phase, 3 wire grounded

Operating frequency of 2450MHz

Height 16-11/32" Depth 15- 9/32"

Height 8-1/16"

Clock ( 1:00 - 12:59 ) Timer (0 - 99 min. 99 seconds)

Microwave Power for Variable Cooking

Repetition Rate;

P-HI .................................................. Full power throughout the cooking time

P-90 .................................................................... approx. 90% of Full Power

P-80 .................................................................... approx. 80% of Full Power

P-70 .................................................................... approx. 70% of Full Power

P-60 .................................................................... approx. 60% of Full Power

P-50 .................................................................... approx. 50% of Full Power

P-40 ..................................................................... approx. 40% of Full Power

P-30 ..................................................................... approx. 30% of Full Power

P-20 .................................................................... approx. 20% of Full Power

P-10 ...................................................................... approx. 10% of Full Powe

P-0 ...................................................... No power throughout the cooking time

Help pad, Sensor Cook pad, Auto Broil pad, Auto Roast pad Auto Bake pad, Sensor Reheat pad, More Time pad, Popcorn pad Timed Defrost pad, Convect pad, Preheat pad, Combination Bake pad Combination Roast pad, Broil pad, Slow Cook pad, Timer pad Number and temperature selection pads, Clock pad, Hold Warm pad Turntable On / Off pad, Power Level pad, Stop/Clear pad, Start / Touch On pad, Fan Hi/Lo/Off, Light.

Oven Cavity Light Yes 20W x 1 Incandescent light bulb

Safety Standard UL Listed FCC Authorized

DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J Canadian Standards Association. Health CANADA, Industry CANADA.

Weight Approx. 71 lbs.

GENERAL INFORMATION

GROUNDING INSTRUCTIONS

This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code and local codes and ordinances. In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the electric current.

WARNING: Improper use of the grounding plug can result in a risk of electric shock.

VMOR205SS DMOR205SS

Electrical Requirements The oven is equipped with a 3-prong grounding plug. DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE GROUNDING PIN FROM THE PLUG. The power supply cord and plug must be connected to a separate 120 Volt AC, 60 Hz, 15 Amp. or more branch circuit, using a grounded receptacle. The receptacle should be located inside the cabinet directly above the Microwave Oven/Hood system mounting location.

3-Pronged Plug

Grounding Pin

3-Pronged Receptacle

Grounded Receptacle Box

OVEN DIAGRAM

1. Oven door with see-through window.

2. Door hinges.

3. Sirrer cover.

4. Turntable motor shaft.

5. Oven lamp. It will light when oven is operating or door is open.

6. Door latches. The oven will not operate unless the door is securely closed.

7. One touch door open button. Push to open door.

8. Auto-Touch control panel.

9. Time display: Digital display, 99 minutes 99 seconds.

10. Ventilation openings.

11. Light Cover.

12. Grease filters.

13. Removable turntable. The turntable will rotate clockwise or counterclockwise. Only remove for cleaning.

14. Removable turntable support.

15.Plug

VMOR205SS DMOR205SS

CONTROL PANEL

NOTE: Some one-touch cooking features as "More Time " are disabled after one minute when the oven is not used. These features are automatically enabled when the door is opened and closed or the STOP/ CLEAR pad s are pressed.

MICROWAVE

Rehe at

Pop co rn Defrost

CONVECTION

Convec Prehea t

Low Mix

Ba ke

Tim e r

Hi/Lo

VMOR205SS Key Sheet

1 Bak ed po tatoe s 2 Frozen vegetables 3 Fresh veg -soft 4 Fresh veg -hard 5 Frozen entrees 6 Hot dogs 7 Bac on 8 Fish, sea food

1 Ham burge rs 2 Chicken pieces 3 Stea ks 4 Fish ste ak s

1 C hicke n 2 Turkey 3 Turk ey bre ast 4 Pork

1 C ak e 2 Brownies 3 Muffins 4 Frenc h fries

275ûF

400ûF

Keep

Wa rm

Tu rn ta b l e

On/Off

Broil

100ûF

350ûF

Fa n

Add-A Minute

High M ix

Roa st

Slow

Cook

150ûF

375ûF

Powe r

Le ve l

Lig ht

300ûF

425ûF

Clock

Stop / Clear

Sensor

Cook

Convec

Broil

Convec

Roa st

Convec

Ba ke

325ûF

450ûF

Help

Start /

To uc h O n

DMOR205SS Key Sheet

OPERATION

DESCRIPTION OF OPERATING SEQUENCE

VMOR205SS DMOR205SS

The following is a description of component functions during oven operation.

OFF CONDITION

Closing the door activates the door sensing switch and secondary interlock switch. (In this condition, the monitor switch contacts are opened.) When oven is plugged in, 120 volts A.C. is supplied to the control unit. (Figure O-1).

1. The display will show "Welcome".

To set any program or set the clock, you must first touch the STOP/CLEAR pad. The display will clear, and " : " will appear.

COOKING CONDITION

Program desired cooking time touching the NUMBER pads. When the START pad is touched, the following operations occur:

1. The contacts of relays are closed and components connected to the relays are turned on as follows. (For details, refer to Figure O-2)

RELAY CONNECTED COMPONENTS RY1 Oven lamp RY2 Power transformer/ Stirrer motor RY4 Turntable motor RY5 Fan motor

2. 120 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3.3 volts A.C. output on the filament winding, and approximately 2000 volts A.C. on the high voltage winding.

3. The filament winding voltage heats the magnetron filament and the H.V. winding voltage is sent to a voltage doubler circuit.

4. The microwave energy produced by the magnetron is channelled through the waveguide into the cavity feedbox, and then into the cavity where the food is placed to be cooked.

5. Upon completion of the cooking time, the power transformer, oven lamp, etc. are turned off, and the generation of microwave energy is stopped. The oven will revert to the OFF condition.

6. When the door is opened during a cook cycle, monitor switch, door sensing switch, secondary switch and third door switch and primary interlock relay are activated with the following results. The circuits to the stirrer motor, the cooling fan motor, the turntable motor, and the high voltage components are de-energized, and the digital read-out displays the time still remaining in the cook cycle when the door was opened.

7. The monitor switch is electrically monitoring the operation of the secondary and third door door switch and primary interlock relay and is mechanically associated with the door so that it will function in the following sequence. (1) When the door opens from a closed position, the

primary interlock relay, door sensing switch, secondary and third door switch open their contacts, and then the monitor switch contacts close.

(2) When the door is closed from the open position, the

monitor switch contacts first open, and then the

contacts of the secondary and third door switch close. If the primaryswitch, secondary switch and secondary interlock relay fail with their contacts closed when the door is opened, the closing of the monitor switch contacts will form a short circuit through the monitor fuse, secondary switch ,third door switch and primary interlock relay, causing the monitor fuse to blow.

POWER LEVEL P-0 TO P-90 COOKING

When Variable Cooking Power is programmed, the 120 volts A.C. is supplied to the power transformer intermittently through the contacts of relay (RY2) which is operated by the control unit within an interval second time base. Microwave power operation is as follows:

VARI-MODE ON TIME OFF TIME Power 10(P-HI) 32 sec. 0 sec.

(100% power) Power 9(P-90) 30 sec. 2 sec.

(approx. 90% power) Power 8(P-80) 26 sec. 6 sec.

(approx. 80% power) Power 7(P-70) 24 sec. 8 sec. (approx. 70% power)

Power 6(P-60) 22 sec. 10 sec. (approx. 60% power)

Power 5(P-50) 18 sec. 14 sec. (approx. 50% power)

Power 4(P-40) 16 sec. 16 sec. (approx. 40% power)

Power 3(P-30) 12 sec. 20 sec. (approx. 30% power)

Power 2(P-20) 8 sec. 24 sec. (approx. 20% power)

Power 1(P-10) 6 sec. 26 sec. (approx. 10% power)

Power 0(P-0) 0 sec. 32 sec. (0% power)

Note: The ON/OFF time ratio does not correspond with the

percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

CONVECTION COOKING CONDITION

PREHEATING CONDITION

Program desired convection temperature by touching the PREHEAT pad and the temperature pad. When the START pad is touched, the following operations occur:

VMOR205SS DMOR205SS

1. The coil of shut-off relays (RY1, RY4, RY5 and RY7) are energized, the oven lamp, turntable motor, cooling fan motor and convection motor are turned on.

2. The coil of relay (RY6) is energized by the control unit. The damper is moved to the closed position, opening the damper switch contacts. The opening of the damper switch contacts sends a signal to the LSI on the control unit de-energizing the relay (RY6) and opening the circuit to the damper motor.

3. The coil of heater relay (RY3) is energized by the control unit and the main supply voltage is applied to the heating element.

4. When the oven temperature reaches the selected preheat temperature, the following operations occur: 4-1 The heater relay is de-energized by the control unit

temperature circuit and thermistor, opening the circuit to the heating element.

4-2. The oven will continue to function for 30 minutes,

turning the heater on and off, as needed to maintain the selected preheat temperature. The oven will shutdown completely after 30 minutes

CONVECTION COOKING CONDITION

When the preheat temperature is reached, a beep signal will sound indicating that the holding temperature has been reached in the oven cavity. Open the door and place the food to be cooked in the oven. Program convection temperature and desired cooking time by touching the CONVECT pad, Temperature pad and NUMBER pad. When the START pad is touched, the following operations occur:

1. The numbers on the digital read-out start to count down to zero.

2. The oven lamp, turntable motor, cooling fan motor and convection motor are energized.

3. Heater relay (RY3) is energized (if the cavity temperature is lower than the selected temperature) and the main supply voltage is applied to the heating element to return to the selected cooking temperature.

4. Upon completion of the cooking time, the audible signal will sound, and oven lamp, turntable motor, cooling fan motor and convection motor are de-energized. At the end of the above 275

convection cycle, if the oven temperature is

F, the circuit to RY5 will be maintained (by the thermistor circuit) to continue operation of the cooling fan motor until the temperature drops below 245 οF, at which time the relay will be de-energized, turning off the fan motor. Relay RY7 will however, open as soon as the convection cycle has ended, turning off the convection motor.

5. At the end of the convection cook cycle, shut-off relay (RY6) is energized turning on the damper motor. The damper is returned to the open position, closing the damper switch contacts which send a signal to the control unit, de-energizing shut-off relay (RY6).

AUTOMATIC MIX COOKING CONDITION

Touch the Combination Bake or Combination Roast pad. The LOW MIX/BAKE pad is preprogrammed for 325 οF with 10% microwave power, while the HIGH MIX/ROAST pad is preprogrammed for 325ο F with 30% microwave power. Program desired cooking time. When the START pad is touched, the following operations occur:

1. The numbers on the digital read-out start to count down to

zero.

2. The shut-off relays (RY1, RY4, RY5 and RY7) are energized, turning on the oven lamp, turntable motor, cooling fan motor and convection motor.

3. The shut-off relay (RY6) is energized. The damper plate is closed from the open position.

4. The heater relay (RY3) is energized, applying the main supply voltage to the heating element.

5. Now, the oven is in the convection cooking condition.

6. When the oven temperature reaches the selected temperature, the following operations occur: 6-1. The power supply voltage is alternated to the

heating element and power transformer.

6-2. The heating element operates through the heater

relay (RY3) contacts and the power transformer operates through the primary interlock relay (RY2) contacts.

6-3. These are operated by the control unit to supply

alternately within a 32 second time base, convection heat and microwave energy.

The relationship between the convection and microwave power operations are as follows.

Note: The ON and OFF time ratio does not correspond

with the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

Note: During alternate Microwave/Convection operation,

the convection heater is energized only if the cavity temperature drops below the set temperature.

26 SEC.6 SEC.

(MICRO.)

(CONVEC.)

(MICRO.)

(CONVEC.)

OFF

LOW MIX

BAKE

12 SEC. 20 SEC.

OFF

32 SEC.

HIGH MIX

ROAST

MICROWAVE POWER

= APPROX. 10%

CONVECTION

TEMPERATURE

= 325ûF (165ûC)

MICROWAVE POWER

= APPROX. 30%

CONVECTION

TEMPERATURE

325ûF (165ûC)

SENSOR COOKING CONDITION

Using the SENSOR COOK, REHEAT or POPCORN function, the foods are cooked or defrosted without figuring time, power level or quantity. When the oven senses enough steam from the food, it relays the information to its microprocessor which will calculate the remaining cooking time and power level needed for best results. When the food is cooked, water vapor is developed. The sensor “senses” the vapor and its resistance increases gradually. When the resistance reaches the value set according to the menu, supplementary cooking is started.

VMOR205SS DMOR205SS

The time of supplementary cooking is determined by experiment with each food category and inputted into the LSI. An example of how sensor works:

1. Potatoes at room temperature. Vapor is emitted very slowly.

MICR

OWAVE

2. Heat potatoes. Moisture and humidity is emitted rapidly. You can smell the aroma as it cooks.

AH SENSOR

MICROWAVE

3. Sensor detects moisture and humidity and calculates cooking time and variable power.

Cooking Sequence.

1. Touch SENSOR COOK, REHEAT or POPCORN pad. When Sensor Cook is touched, to choose menu the number pad should be touched.

NOTE: The oven should not be operated on SENSOR

COOK, REHEAT or POPCORN immediately after plugging in the unit. Wait five minutes before cooking on SENSOR COOK, REHEAT or POPCORN.

2. The coil of shut-off relays (RY1, RY4 and RY5) are energized, the oven lamp, turntable motor and cooling fan motor are turned on, but the power transformer is not turned on.

3. After about 32 seconds, the cook relay (RY2) is energized. The power transformer is turned on, microwave energy is produced and first stage is started. The 32 seconds is the cooling time required to remove any vapor from the oven cavity and sensor.

NOTE: During this first stage, do not open the door or touch

STOP/CLEAR pad.

4. When the sensor detects the vapor emitted from the food, the display switches over to the remaining cooking time and the timer counts down to zero. At this time, the door may be opened to stir food, turn it or season, etc.

5. When the timer reaches zero, an audible signal sounds. The shut-off relay and cook relay are de-energized and the power transformer, oven lamp, etc. are turned off.

6. Opening the door or touching the STOP/CLEAR pad, the time of day will reappear on the display and the oven will revert to an OFF condition.

CONVEC BROIL, CONVEC ROAST, CONVEC BAKE

CONVEC BROIL, CONVEC ROAST and CONVEC BAKE

will automatically compute the oven temperature, microwave power and cooking time for broiling, roasting and baking. Set the desired program by touching one of the CONVEC BROIL, CONVEC ROAST or CONVEC BAKE pad, and number pad. Enter the weight by touching the Number pads. When the START pad is touched, the following operations occur:

1. The COOK indicator will light and the CONV or MIX indicator will light.

2. The cooking time will appear on the display and start counting down to zero. The cooking time is adjusted automatically according to the weight of the food.

3. The shut-off relays (RY1, RY4, RY5 and RY7) are energized, turning on the oven lamp, turntable motor, cooling fan motor and convection motor. The power supply voltage is applied to the heating element.

4. Now, the oven is in the convection cooking mode or Automatic Mix Cooking condition.

5. When the oven temperature has reached the programmed convection temperature, the oven goes into the programmed cooking mode.

6. At the end of the cooking cycle, the damper is returned to the open position and the oven will go to the off condition. The cooling fan will remain on until the oven has cooled.

TIMED DEFROST COOKING

The DEFROST key is a special function key to defrost meats and poultry faster and better. DEFROST automatically defrosts roast beef, etc.. When the DEFROST is selected and the food weight is entered by using the DEFROST pad, the oven will cook according to the special cooking sequence.

FIRE SENSING FEATURE (MICROWAVE MODE)

This model incorporates a sensing feature which will stop the oven's operation if there is a fire in the oven cavity during microwave cooking. This is accomplished by the LSI repeatedly measuring the voltage across the temperature measurement circuit (thermistor) during it's 32-seconds time base comparing the obtained voltage measurements. If the most recent voltage measured is 100mV greater than the previous voltage measured, the LSI judges it as a fire in the oven cavity and switches off the relays to the power transformer and fan motor. The LSI also stops counting down and closes the damper plate so that no fresh air will enter the oven cavity. Please refer to the following section for a more detailed description.

Operation

The following operation will start 4 minutes after the start pad is touched. Please refer to the timing diagrams below.

1. The thermistor operates within a 32-seconds time base and it is energized for three (3) seconds and off for 29 seconds. Two (2) seconds after the thermistor is energized, the voltage across the temperature measurement circuit is sampled by the LSI and twenty one (21) seconds after the thermistor is cut off the LSI turns on the convection motor for six (6) seconds.

2. The above procedure is repeated. If the difference between the first voltage measured (in step 1) and the voltage measured when the procedure is repeated (step

2) is greater than 100mV the LSI makes the judgment that there is a fire in the oven cavity and will switch off the relays to the power transformer and fan motor. The LSI

VMOR205SS DMOR205SS

also stops counting down and closes the damper door so that no fresh air will enter the oven cavity.

3. Once the fire sensor feature has shut the unit down, the programmed cooking cycle may be resumed by pressing the "START" pad or the unit may be reset by pressing the "CLEAR" pad.

IMPORTANT: During sensor cooking operation, the fire sensing operation sequence will not begin until the AH sensor has detected vapors and initiated a sensor cooking cycle. This is because the operation of the convection fan would interfere with the AH sensor's vapor detection.

CONVECTION

MOTOR

THERMISTOR

Sensing

Voltage

0 2 24 30 64 (sec.)

OFF

3 sec.

OFF

Sensing the voltage across the temperature measurement circuit.

6 sec.

32 (sec.)

VENTILATION METHODS HOT AIR EXHAUST

1. VERTICAL VENTING For this venting method, hot air rising from the conventional range below is drawn in by the hood fan motor through the grease filters at the right and left sides of the base cover, up through the right and left side intake ducts, then discharged vertically at rear center top of the oven, into the customer's vent system.

3. RE-CIRCULATION (INSIDE VENTING) The air handing is same as VERTICAL VENTING except that the final air discharge is directed horizontally through the upper front of the oven into the kitchen. IN this case, the accessory charcoal filter lit RK-220 must be provided to filter the air before it leaves the oven.

: AIR FLOW

HOOD FAN MOTOR

HOOD EXHAUST LOUVER

HOOD INTAKE DUCT R

CHARCOAL FILTER

: AIR FLOW

HOOD FAN MOTOR

HOOD INTAKE DUCT R

GREASE FILTER

TO DUCTTO DUCT

2. HORIZONTAL VENTING The air handing is same as VERTICAL VENTING except that the final air discharge is directed horizontally out from the top rear of the oven into the customer's vent system.

: AIR FLOW

HOOD FAN MOTOR

HOOD INTAKE DUCT R

TO DUCT

GREASE FILTER

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. CLOCK APPEARS ON DISPLAY.

VMOR205SS DMOR205SS

MONITOR

RED

FUSE (20A)

BLK

BRN

RESISTOR

WHT

NOISE

BLK

BRN,PNK

PNK

HOOD MOTOR

RED

BRN

BLU

PPL

HOOD

CAPACITOR

RED

BRN

GRY

YLW

BLK

RED

HOOD FAN

GRN

120VAC

GND

60Hz

WHT

NOTES:

1. Circuits / Wire colors subject to change without notice

2. Terminal with projection or opposite blue mark on lamp socket

3. Only certain models use the absolute humidity sensor.

4. Power transformer top (finish lead) terminal must be connected to the hot wire (RED)

BLK

YLW

(CONV. SIDE)

RED

NOISE FILTER

GRY

must be connected to neutral wire.

THERMAL CUTOUTS

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME PROGRAMMED.

3. START PAD TOUCHED.

HOOD LAMP

MAGNETRON

TEMPERATURE

CONTROL UNIT

RY9

RY10

YLW

BRN

FUSE

ORG ORG

ORG

RY8

PNK

ORG

YLW

DAMPER MOTOR

BLU

RY6

ORG

FAN MOTOR

PPL

SECONDARY

INTERLOCK

ORG

TURNTABLE MOTOR

B1 B7

RY5

SWITCH

BLK, BRN

TTM

WHT

BLK YLW

CONVECTION MOTOR

RY4

ORG

YLW

BLK

ORG

ELEMENT

OVEN LAMP

WHT

BRN

GRY

N.O. RY1

RY7

BLU

HEATING

BRN

PPL

WHT

PPL

N.O.

COM.

RY3

RY2

RY1

RY3

COM. RY1

GRY

Figure O-1. Oven Schematic - Off Condition

BLK

ORG

GRN

DOOR SENSING SWITCH

THERMISTOR

RED

GRN

PNK

BLK

RY2

INTERLOCK RELAY

PRIMARY

N.O. RY2

WHT WHT

BLK

E6 E3

AH SENSOR

BLK

MONITOR

SWITCH

DAMPER SWITCH

BRN

WHT

STIRRER MOTOR

YLW

BLK,BRN

THIRD DOOR

SWITCH

STM

RED

BLU, GRY

WHT

POWER TRANSFORMER

MAGNETRON

HIGH VOLTAGE CAPACITOR XXX μF

WHT

HIGH VOLTAGE RECTIFIER

MONITOR

RED

FUSE (20A)

YLW

BLK

(CONV. SIDE)

HOOD FAN

THERMAL CUTOUTS

GRY

BRN

RESISTOR

WHT

BRN,PNK

NOISE

BLK

RED

GRN

120VAC

GND

60Hz

WHT

NOTES:

1. Circuits / Wire colors subject to change without notice

2. Terminal with projection or opposite blue mark on lamp socket

3. Only certain models use the absolute humidity sensor.

4. Power transformer top (finish lead) terminal must be connected to the hot wire (RED)

BLK

YLW

RED

NOISE FILTER

GRY

must be connected to neutral wire.

PNK

HOOD MOTOR

MAGNETRON

TEMPERATURE

FUSE

CONTROL UNIT

RY9

RY10

YLW

BRN

ORG ORG

ORG

RY8

PNK

ORG

YLW

DAMPER MOTOR

BLU

RED

BRN

BLU

PPL

HOOD

CAPACITOR

RED

HOOD LAMP

BRN

GRY

RY6

ORG

FAN MOTOR

PPL

SECONDARY

INTERLOCK

SWITCH

ORG

TTM

TURNTABLE MOTOR

B1 B7

RY5

BLK, BRN

WHT

BLK YLW

CONVECTION MOTOR

RY4

ORG

YLW

BLK

ORG

WHT

BRN

GRY

N.O. RY1

RY7

RY1

COM.

RY1

BLU

GRY

OVEN LAMP

PPL

COM.

RY2

ORG

ELEMENT

HEATING

BRN

PPL

COM. RY3

GRN

DOOR SENSING SWITCH

THERMISTOR

RED

GRN

PNK

N.O. RY3

RY3

BLK

RY2

INTERLOCK RELAY

PRIMARY

N.O. RY2

WHT WHT

BLK

AH SENSOR

E6 E3

BLK

DAMPER SWITCH

BRN

Figure O-2. Oven Schematic - Microwave Cooking Condition

MONITOR

SWITCH

WHT

STIRRER MOTOR

BLK

YLW

BLK,BRN

THIRD DOOR

SWITCH

STM

RED

BLU, GRY

WHT

POWER TRANSFORMER

MAGNETRON

HIGH VOLTAGE CAPACITOR XXX μF

WHT

HIGH VOLTAGE RECTIFIER

VMOR205SS DMOR205SS

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. CONVECTION PAD TOUCHED.

3. DESIRED TEMP. TOUCHED.

4. START PAD TOUCHED.

MONITOR

RED

FUSE (20A)

YLW

BLK

(CONV. SIDE)

HOOD FAN

THERMAL CUTOUTS

GRY

BRN

RESISTOR

WHT

BRN,PNK

NOISE

BLK

RED

GRN

120VAC

GND

60Hz

WHT

NOTES:

1. Circuits / Wire colors subject to change without notice

2. Terminal with projection or opposite blue mark on lamp socket

3. Only certain models use the absolute humidity sensor.

4. Power transformer top (finish lead) terminal must be connected to the hot wire (RED)

BLK

YLW

RED

NOISE FILTER

GRY

must be connected to neutral wire.

PNK

HOOD MOTOR

MAGNETRON

TEMPERATURE

FUSE

CONTROL UNIT

RY9

RY10

YLW

BRN

ORG ORG

ORG

RY8

PNK

ORG

YLW

DAMPER MOTOR

RED

BRN

BLU

PPL

HOOD

CAPACITOR

RED

HOOD LAMP

BRN

GRY

SECONDARY

INTERLOCK

SWITCH

BLK YLW

ORG

CONVECTION MOTOR

RY4

YLW

BLK

ORG

WHT

BRN

GRY

N.O.

RY1

RY7

RY1

COM. RY1

BLU

GRY

ORG

BLK, BRN

TTM

FAN MOTOR

TURNTABLE MOTOR

BLU

WHT

PPL

B1 B7

RY5

RY6

OVEN LAMP

PPL

COM.

RY2

ORG

ELEMENT

HEATING

BRN

PPL

COM.

RY3

GRN

DOOR SENSING SWITCH

THERMISTOR

RED

GRN

PNK

N.O. RY3

RY3

BLK

RY2

INTERLOCK RELAY

PRIMARY

N.O. RY2

WHT WHT

BLK

E6 E3

AH SENSOR

BLK

MONITOR

SWITCH

DAMPER SWITCH

BRN

WHT

BLK,BRN

STM

STIRRER MOTOR

WHT

BLU, GRY

BLK

YLW

THIRD DOOR

SWITCH

RED

WHT

POWER TRANSFORMER

HIGH VOLTAGE CAPACITOR XXX μF

HIGH VOLTAGE RECTIFIER

Figure O-3. Oven Schematic - Convection Cooking Condition (CONVEC, PREHEAT, BROIL, SLOW COOK)

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. MIX COOKING PAD TOUCHED.

3. DESIRED TEMP. TOUCHED.

4. COOKING TIME PROGRAMMED.

5. START PAD TOUCHED.

NOTE: RY2 and RY3 will alternately close during cook cycle

MAGNETRON

MONITOR

RED

FUSE (20A)

YLW

BLK

(CONV. SIDE)

HOOD FAN

THERMAL CUTOUTS

GRY

BRN

NOISE

RESISTOR

WHT

BRN,PNK

BLK

RED

GRN

120VAC

GND

60Hz

WHT

NOTES:

1. Circuits / Wire colors subject to change without notice

2. Terminal with projection or opposite blue mark on lamp socket

3. Only certain models use the absolute humidity sensor.

4. Power transformer top (finish lead) terminal must be connected to the hot wire (RED)

BLK

YLW

RED

NOISE FILTER

GRY

must be connected to neutral wire.

Figure O-4. Oven Schematic - Automatic Mix cooking Condition

PNK

HOOD MOTOR

MAGNETRON

TEMPERATURE

FUSE

CONTROL UNIT

RY9

RY10

YLW

BRN

ORG ORG

ORG

RY8

PNK

ORG

YLW

DAMPER MOTOR

BLU

RED

BRN

BLU

PPL

HOOD

CAPACITOR

RED

HOOD LAMP

BRN

GRY

RY6

ORG

FAN MOTOR

PPL

SECONDARY

ORG

TURNTABLE MOTOR

B1 B7

RY5

INTERLOCK

SWITCH

TTM

WHT

BLK, BRN

BLK YLW

CONVECTION MOTOR

RY4

ORG

YLW

BLK

ORG

WHT

BRN

GRY

N.O. RY1

RY7

RY1

COM. RY1

BLU

GRY

OVEN LAMP

PPL

COM.

RY2

ORG

ELEMENT

HEATING

BRN

PPL

COM.

RY3

GRN

DOOR

SENSING

SWITCH

THERMISTOR

RED

GRN

PNK

N.O. RY3

RY3

BLK

RY2

INTERLOCK RELAY

PRIMARY

N.O. RY2

WHT WHT

BLK

E6 E3

AH SENSOR

BLK

MONITOR

DAMPER SWITCH

BRN

WHT

SWITCH

STM

STIRRER MOTOR

BLK

YLW

BLK,BRN

THIRD DOOR

SWITCH

RED

BLU, GRY

WHT

POWER TRANSFORMER

MAGNETRON

HIGH VOLTAGE CAPACITOR XXX μF

WHT

HIGH VOLTAGE RECTIFIER

DESCRIPTION AND FUNCTION OF COMPONENTS

VMOR205SS DMOR205SS

DOOR OPEN MECHANISM

The door is opened by pushing the open button on the control panel, refer to the Figure D-1. When the open button is pushed, the open button pushes up the open lever, and then the open lever pushes up the latch head. The latch heads are moved upward and released from latch hook. Now the door will open.

Figure D-1. Door Open Mechanism

LATCH HOOK

DOOR

LATCH HEADS

OPEN LEVER

DOOR SENSING SWITCH

MONITOR FUSE

MONITOR SWITCH

SECONDARY INTERLOCK SWITCH

THIRD DOOR SWITCH

SECONDARY SWITCH, THIRD DOOR SWITCH & DOOR SENSING SWITCH

The secondary switch and third switch mounted parrallel to each other horizontally in the upper positions of the latch hook, the door sensing switch is mounted horizontally in the upper position of the latch hook. They are activated by the latch head on the door. When the door is opened, the switches interrupt the power to all high voltage components, except the oven lamp . A cook cycle cannot take place until the door is firmly closed thereby activating all interlock switches. The secondary interlock system consists of the door sensing switch and the primary interlock relay located on the control circuit board.

MONITOR SWITCH

The monitor switch is activated (the contacts opened) by the latch head on the door while the door is closed. The switch is intended to render the oven inoperative, by means of blowing the monitor fuse, when the contacts of the primary switch and secondary switch fail to open when the door is opened.

Functions:

1. When the door is opened, the monitor switch contact close (to the ON condition) due to their being normally closed. At this time the secondary interlock relay, primary switch and secondary switch are in the OFF condition (contacts open) due to their being normally open contact switches.

2. As the door goes to a closed position, the monitor switch contacts are first opened and then the door sensing switch, primary switch and secondary switch contacts close. (On

opening the door, each of these switches operate inversely.)

3. If the door is opened, and the secondary interlock relay, primary switch and secondary switch contacts fail to open, the monitor fuse blows simultaneously with closing of the monitor switch contacts.

CAUTION: BEFORE REPLACING A BLOWN MONITOR

FUSE, TEST THE SECONDARY INTERLOCK RELAY, SECONDARY SWITCH, DOOR SENSING SWITCH, MONITOR SWITCH AND PRIMARY SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").

NOTE: MONITOR FUSE, PRIMARY SWITCH AND

MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY.

TEMPERATURE FUSE (MG)

The temperature fuse located near the waveguide is designed to prevent damage to the magnetron if an over heated condition develops in the tube due to cooling fan failure, obstructed air guide, dirty or blocked air intake, etc. Under normal operation, the temperature fuse remains closed. However, the temperature fuse will open at 302οF (150οC) causing the oven to shut down.

THERMAL CUT-OUT (HOOD )

This thermal cut-out located on the base plate right. It is designed to automatically turn on the hood fan motor whenever the hot air rising from the conventional range below causes the temperature at the thermal cut-out to rise to 140οF (60οC) or higher, thus removing this hot air from around microwave oven. When the temperature around the thermal cut-out drops to 113οF (45οC) or lower, the thermal cut-out shuts off the food fan motor.

TURNTABLE MOTOR

The turntable motor rotates the turntable located on the bottom of the oven cavity, so that the foods on the turntable cook evenly during cooking. Turntable will turn in either direction. The turntable motor can be turned off by touching TURNTABLE ON/OFF pad.

COOLING FAN MOTOR

The cooling fan motor drives a blade which draws external cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and vapors given off from the heating foods. It is then exhausted through the exhausting air vents at the oven cavity.

HOOD FAN MOTOR

The hood fan motor is a two-speed, single-phase, double pole induction type, requiring a hood fan capacitor. It is located outside the upper rear part of the oven cavity, is to remove, from around the oven, hot air rising from the conventional electric or gas range over which it is installed. This air is then expelled either vertically or horizontally through the customer supplied duct system, or discharged back into the kitchen.

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