Subzero Wolf MD24 User manual
Page 2
MD24 and MD30
MD24 and MD30
General Information
1-1
#824820 - Revision A - November, 2013
INTRODUCTION
This Wolf Microwave Drawer Technical Service Manual, Part #824820, has been compiled with information provided
by the Sharp Electronics Corporation. This manual provides the most recent technical service information that will
enable the service technician to troubleshoot and diagnose malfunctions, perform necessary repairs and return a
Wolf Microwave Drawer to proper operational condition.
The Service Technician should read the complete instructions contained in this manual before initiating any repairs
on a Wolf Appliance.
IMPORTANT SAFETY INFORMATION
Below are Product Safety Labels used in this manual.
The "Signal Words" used are WARNING or CAUTION.
When reviewing this manual, please note these differ-
ent Product Safety Labels placed at the beginning of
certain sections of this manual. You must follow the
instructions given in the boxes of the Product Safety
Labels in order to avoid personal injury and/or product
damage.
The sample Product Safety Labels below illustrate the
precautions that should be taken when the signal word
is observed.
TECHNICAL ASSISTANCE
If you should have any questions regarding the appli-
ance and/or this manual, please contact:
Wolf Appliance, Inc.
ATTN: Service Department
P.O. Box 44988
Madison, WI 53744 - 4988
Customer Assistance
Phone #: (800) 332 - 9513
Facsimile #: (608) 441 - 5887
Technical Assistance
(For Technicians in Customer’s Homes Only)
Phone #: (800) 919 - 8324
Warranty Claims
Phone #: (800) 404 - 7820
Facsimile #: (608) 441 - 5886
Service Department e-mail Address:
Main Office Hours:
8:00 AM to 5:00 PM Central Time
Monday through Friday
(24/7 Phone Coverage)
INDICATES THAT HAZARDOUS OR UNSAFE
PRACTICES COULD RESULT IN SEVERE PER-
SONAL INJURY OR DEATH!
Indicates that hazardous or unsafe practices could
result in minor personal injury, and/or product
damage, and/or property damage!
In addition, please pay attention to the signal word
“NOTE”, which highlights information that is especially
important for the topic being covered.
This manual is designed to be used by Authorized Service Personnel only. Wolf Appliance, Inc. assumes
no responsibility for any repairs made on Wolf appliance units by anyone other than Authorized Service
Technicians.
The information and images contained in this manual are the copyright property of Wolf Appliance, Inc. Neither this
manual nor any information or images contained herein may be copied or used in whole or in part without the
express written consent of Wolf Appliance, Inc.©, all rights reserved.
Page 3
General Information
MD24 and MD30
MD24 and MD30
1-2 #824820 - Revision A - November, 2013
TABLE OF CONTENTS
Page #
Page #
Section 1 - General Information
Introduction ........................................................................1-1
Important Safety Information ............................................1-1
Technical Assistance ........................................................1-1
Table of Contents ..............................................................1-2
Warranty Information ........................................................1-3
Model Warranty Tag Information ......................................1-3
Model Warranty Tag Location ............................................1-3
Microwave Drawer Features ..............................................1-4
Microwave Drawer Layout..................................................1-4
Touch Control Panel Layout ..............................................1-4
Cookware Suggestions ......................................................1-5
Radio and TV Interference ................................................1-5
Care and Cleaning ............................................................1-5
Section 2 - Installation Information
Installation Information ......................................................2-2
Electrical Requirements ....................................................2-2
Installation Requirements ..................................................2-2
Clearances and Dimensions MD24....................................2-3
Clearances and Dimensions MD30....................................2-4
MD24 and MD30 Specifications ........................................2-4
Section 3 -Theory and Operation
Control Lock ......................................................................3-2
Open/Close ........................................................................3-2
Clock ................................................................................3-2
Timer ................................................................................3-2
Audible Signal ..................................................................3-2
Cook Time Completion Reminder ....................................3-2
Demonstration Mode ........................................................3-3
Power Level ......................................................................3-3
Multiple Sequence Cooking ..............................................3-3
Auto Start ..........................................................................3-4
Add Minute ........................................................................3-4
Keep Warm ........................................................................3-4
Popcorn ............................................................................3-4
Melt ................................................................................3-4
Soften ................................................................................3-4
Beverage ..........................................................................3-5
Wolf Gourmet ....................................................................3-5
Sensor Reheat ..................................................................3-5
Time Adjustment (sensor cooking) ....................................3-5
Auto Defrost ......................................................................3-5
Manual Defrost ..................................................................3-5
Off Condition ......................................................................3-6
Cooking Condition ............................................................3-6
Power Level ......................................................................3-6
Sensor Cooking Condition ................................................3-7
Section 4 - Component Access and Removal
Warnings and Cautions ....................................................4-2
Microwave Measurement Procedure ................................4-3
Before Operating Oven after Service ................................4-3
Emergency Opening of Drawer ........................................4-4
Un-installing the Microwave Drawer ..................................4-4
Removing Cord and Outer Case ......................................4-4
Accessing Rear Components ............................................4-4
Metal Key Unit Frame Assembly ........................................4-4
Noise Filter Board Replacement ......................................4-5
Latch Hook and Microswitch Removal ..............................4-5
Adjusting Monitor, Stop and Secondary Interlock ............4-5
After Adjusting Latch Hook ................................................4-6
Drawer Assembly and Choke Removal..............................4-6
Drawer Support Angle Removal ........................................4-6
Drawer Latch Removal ......................................................4-7
Auto Drawer Gear Removal ..............................................4-7
Auto Drawer Gear Installation ..........................................4-7
Rack Gear/Oil Damper Removal........................................4-8
After Reassembly ..............................................................4-8
Section 5 - Troubleshooting Guide
Warnings and Cautions ....................................................5-2
Troubleshooting Chart ......................................................5-3
Control Panel Assembly Test ............................................5-4
CPU-Drawer Board & Display Harness Test ....................5-4
PSU-Drawer Board and Relay Test ..................................5-5
Defrost Test ......................................................................5-6
PSU-Drawer Board Fuse is Open ....................................5-6
AH Sensor Test ................................................................5-8
Magnetron Assembly Test (includes Power Output) ......5-10
Thermal Cut-Out Test ....................................................5-11
Secondary Interlock Switch Test ......................................5-11
Stop Switch Test ..............................................................5-11
Monitor Switch Test ........................................................5-12
Blown Monitor Fuse Test ................................................5-12
MD Transformer Test ......................................................5-13
Noise Filter Test ..............................................................5-13
High Voltage Rectifier Test ..............................................5-14
Relay Diode Test ............................................................5-14
High Voltage Capacitor Test ............................................5-15
PSU-Drawer Board Picture ............................................5-15
CPU-Drawer Board Picture ............................................5-16
SW PSU-Drawer Board Picture ......................................5-16
Noise Filter Board Picture ..............................................5-16
Section 6 - Wiring Diagrams
MD Wiring Schematic (off condition) ................................6-2
MD Wiring Diagram ..........................................................6-3
Control Unit Circuit ............................................................6-4
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MD24 and MD30
MD24 and MD30
General Information
1-3
#824820 - Revision A - November, 2013
WARRANTY INFORMATION
This page contains a summary of the 2 & 5 Year Warranty that is supplied with every Wolf product, followed by a
Non Residential Warranty Summary and then notes about the warranties.
TWO & FIVE YEAR Warranty Summary
• Two year TOTAL PRODUCT warranty, parts and labor.
• Limited Parts Only Warranty for the 3rd through 5th year on the following parts: Transformer, Magnetron,
Capacitor, Rectifier, Electronic Control System, etc.
NOTE: This warranty only applies to products installed for normal residential use in the United States or Canada.
NON RESIDENTIAL Warranty Summary
• Two year TOTAL PRODUCT warranty, parts and labor.
NOTE: This warranty only applies to products installed in test kitchens, culinary and school kitchens, and other
installations which help promote Wolf Appliance products. Restaurant installations and other similar commercial
applications carry no warranty.
WARRANTY NOTES:
•All warranties begin at the time of the unit’s initial installation.
•All Warranty and Service information collected by Wolf Appliance, Inc. is arranged and stored under the unit seri-
al number and/or the customer’s name. It is requested that you have the model and serial number available
whenever contacting the factory or parts distributor.
•See Figures 1-1 & 1-2 for Rating Plate layout and location.
Name plate: Open the Microwave
Drawer fully. The label is on the
bottom of the cavity facing up from
the flat surface.
Figure 1-2. Rating Plate Label
Figure 1-1. Rating Plate Label
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General Information
MD24 and MD30
MD24 and MD30
1-4 #824820 - Revision A - November, 2013
DRAWER MICROWAVE FEATURES
• Built-in microwave oven with 950 watts of power
• 30” (762mm) model allows microwave to be built in to fit below a Wolf built-in E-Series or M-Series oven
• Classic stainless steel finish
• Sensor cooking
• Keep Warm allows you to keep food warm up to 90 minutes
• Easy-to-operate control panel and 10 programmable power levels
• Interactive display—99 minutes, 99 seconds
• Oven drawer with window
• Control lock
• Oven light comes on when oven is operating or drawer is open
• Tight drawer seals with automatic drawer open/close
Figure 1-3. Drawer Microwave Layout
Figure 1-4. Touch Control Panel Layout
OVEN DIAGRAM (MD30PE/S)
2
1
8
5
4
3
7
6
1
Control panel
2
Waveguide cover DO NOT REMOVE
3
Menu Label
4
Drawer sealing surfaces
5
Drawer light
6
Microwave Drawer guides
7
Vent
8
Name plate: open the Microwave Drawer fully.
The label is on the bottom of the cavity
facing up from the at surface.
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MD24 and MD30
MD24 and MD30
General Information
1-5
#824820 - Revision A - November, 2013
COOKWARE SUGGESTIONS
NOTE: Make sure the utensil does not touch the interior walls during cooking.
Use these utensils for safe microwave cooking and reheating:
• Glass ceramic
• Heat-resistant glass
• Microwave-safe plastics
• Microwave-safe paper plates
• Microwave-safe pottery, stoneware and porcelain
• Browning dish (Do not exceed recommended preheating time. Follow manufacturer’s directions.)
These items can be used for short time reheating of foods that have little fat or sugar in them:
• Wood, straw, wicker
DO NOT USE:
• Metal pans and bake-ware
• Dishes with metallic trim
• Non-heat-resistant glass
• Non-microwave-safe plastics (margarine tubs)
• Recycled paper products
• Brown paper bags
• Food storage bags
• Metal twist-ties
NOTE: To check if a dish is safe for microwaving, place the empty dish in the oven and microwave on HIGH for 30
seconds. If the dish becomes very hot, DO NOT use it for microwaving.
RADIO OR TV INTERFERENCE
Should there be any interference caused by the drawer microwave to your radio or TV, check that the drawer
microwave is on a different electrical circuit, relocate the radio or TV as faraway from the drawer as feasible or check
position and signal of receiving antenna.
CARE AND CLEANING
Stainless Steel Surface: The exterior should be wiped often with a soft damp cloth and polished with a soft dry
cloth to maintain its beauty. There are also a variety of products designed especially for cleaning and shining the
stainless exterior of the oven. We recommend that the cleaner be applied to a soft cloth and then carefully used on
the stainless exterior rather than sprayed directly on to it. Follow package directions carefully.
Front Side of Drawer: Wipe the window on both sides with a soft damp cloth to remove any spills or spatters.
Metal parts will be easier to maintain if wiped frequently with a soft damp cloth. Avoid the use of spray and other
harsh cleaners as they may stain, streak or dull the door surface.
Touch Control Panel: If desired, the touch pads may be deactivated before cleaning. See the CONTROL LOCK
information on page 3-2 of section 3, Theory and Operation, of this manual. Wipe the panel with a cloth dampened
slightly with water only. Dry with a soft cloth. Do not scrub or use any sort of chemical cleaners. Close door and fol-
low directions on page 3-2 for turning CONTROL LOCK off. Touch STOP/CLEAR.
Interior: Cleaning is easy because no heat is generated to the interior surfaces; therefore, there is no baking and
setting of spills or spattering. To clean the interior surfaces, including drawer sealing surfaces, wipe with a soft damp
cloth. Do not use abrasive or harsh cleaners or scouring pads. For heavier soil, use mild soap; wipe clean with a
soft damp cloth. Do not use any chemical oven cleaners.
Drawer Guides: Remove the food crumbs from the drawer guides. Wipe with a soft dry cloth in order to keep the
drawer Microwave opening and closing smoothly.
Odor Removal: Occasionally, a cooking odor may remain in the drawer microwave. To remove, combine 1 cup
(250 ml) water, grated peel and juice of one lemon and several whole cloves in a 2-cup(500 ml) glass measuring
cup. Boil for several minutes using 100% power. Allow to sit in the drawer microwave until cool. Wipe interior with a
soft cloth.
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MD24 and MD30
Installation Information
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#824820 - Revision A - November, 2013
INSTALLATION INFORMATION
Below are the Product Safety Labels used in this manual. This section of the manual covers some of the installation
issues that a service technician may need to know when servicing a Wolf Microwave Drawer. If additional installation
information is needed, after reviewing this section of the manual, please refer to the Installation Guide or contact the
Wolf Appliance Customer Care Department.
•TO REDUCE RISK OF TIPPING, MICROWAVE DRAWER MUST BE SECURED BY A PROPERLY INSTALLED
ANTI-TIP BLOCK.
•STEPPING, LEANING OR SITTING ON DRAWER MAY RESULT IN SERIOUS INJURIES AND CAN ALSO
CAUSE DAMAGE TO MICROWAVE DRAWER.
•FOR SAFETY CONSIDERATIONS DO NOT INSTALL DRAWER IN ANY COMBUSTIBLE CABINETRY, WHICH
IS NOT IN ACCORD WITH THE STATED CLEARANCES AND DIMENSIONS PROVIDED IN PRODUCT INSTAL-
LATION INSTRUCTIONS.
•NEVER LEAVE CHILDREN ALONE OR UNATTENDED IN THE AREA WHERE A MICROWAVE DRAWER IS IN
USE. NEVER LEAVE DRAWER OPEN WHEN IT IS UNATTENDED.
•DO NOT USE MICROWAVE DRAWER AS A STORAGE SPACE. THIS CREATES A POTENTIALLY HAZ-
ARDOUS SITUATION. CHECK THAT THE TIME-OF-DAY IS IN THE DISPLAY. IF NOT, TOUCH STOP/CLEAR
TO PREVENT UNINTENDED USE.
•THIS MICROWAVE DRAWER MUST BE ELECTRICALLY GROUNDED IN ACCORDANCE WITH LOCAL
CODES.
•DO NOT USE AN EXTENSION CORD. IF POWER SUPPLY CORD IS TOO SHORT, HAVE A QUALIFIED ELEC-
TRICIAN OR SERVICEMAN INSTALL AN OUTLET NEAR THE APPLIANCE.
Electrical Requirements
This appliance must be grounded. The Microwave
Drawer is equipped with a 4 foot cord having a ground-
ing wire with a 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 risk of electric shock by pro-
viding an escape wire for the electric current.
• 120 volt 60Hz, AC only, 15 amp protected electrical
supply.
• Dedicated electrical circuit serving only this appli-
ance.
• A properly grounded 3-prong receptacle
(See Figure 2-1).
Grounded
Receptacle Box
Grounding Pin
3-Pronged R eceptacle
Figure 2-1. Grounded Receptacle
Neutral
Line Voltage
(Power)
Installation Requirements
The Microwave Drawer oven can be installed in a standard or flush inset application. Location of the electrical sup-
ply within the oven opening may require additional cabinet depth. Finish the edges of the opening. They may be
visible when the drawer is open. For flush inset installations, a minimum 1/8” reveal is required on the top and sides
and 11/16” reveal on the bottom. A sales accessory is required to direct air away from the unit. Accessories are
available through an authorized Wolf dealer. To endure consistent reveals, each corner of the opening must be
exactly 90 degrees.
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Installation Information
MD24 and MD30
2-3 #824820 - Revision A - November, 2013
Clearances and Dimensions
Dimensions shown on this page must be used. Given dimensions provide minimum clearance.
NOTES:
• The Microwave Drawer can also be installed using an electrical outlet in an adjacent cabinet within the area
where the provided electrical cord can reach. Power cord access hole in cabinet should be a minimum of
1-1/2”(38mm) diameter hole and de-burred of all sharp edges.
• Always allow sufficient power cord length to the electrical outlet to prevent tension.
Contact surface must be solid and level. Pay special attention to the floor on which the Microwave Drawer will sit.
The floor of the opening should be constructed of plywood strong enough to support the weight of the oven, about
125 pounds (57 kg).
Check location where the Microwave Drawer will be installed for proper electrical supply.
Your oven can be built into a cabinet or wall by itself or under an electric wall oven.
Figure 2-2. 24” Microwave Drawer Dimensions
21
7
/
8
"
(556)
BEHIND FRAME
15
1
/
8
"
(384)
23
5
/
8
"
(600)
POWER CORD
CHANNEL
1
1
/
4
"
(32)
4
5
/
8
"
(118)
1
3
/
4
"
(45)
14
5
/
8
"
(372)
16
1
/
2
"
(419)
OPEN DRAWER
STANDARD INSTALLATION FLUSH INSET INSTALLATION
E
W
FLUSH INSET WIDTH
FRONT VIEW
SIDE
VIEW
FINISHED
CLEATS
23
1
/
4
"
(591 )
FLUSH INSET
DEPTH
1
1
/
4
"
(32)
NOTE: Dashed line represents prole of unit.
15
15
/
16
"
(405)
FLUSH INSET
HEIGHT
7
/
16
"
(11 )
3
/
4
"
(19)
ANTI-TIP BLOCK
A
TOP VIEW
E
FRONT ViEW
SIDE
VIEW
22"
(559)
OPENING
DEPTH
NOTE: All Microwave Drawer ovens require the same opening dimensions.
.
Dashed line represents prole of unit
.
14
3
/
4
"
(375)
OPENING
HEIGHT
ANTI-TIP BLOCK
W
OPENING WIDTH
TOP VIEW
BASE SUPPORT
30
1
/
8
"
(765)
22
1
/
8
"
(562)
4” (102)
Figure 2-3. 24” Microwave Drawer Cabinet Dimensions
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MD24 and MD30
Installation Information
2-4
#824820 - Revision A - November, 2013
Figure 2-5. 30” Microwave Drawer Cabinet Dimensions
STANDARD INSTALLATION FLUSH INSET INSTALLATION
E
W
FLUSH INSET WIDTH
FRONT VIEW
SIDE
VIEW
FINISHED
CLEATS
23
1
/
4
"
(591 )
FLUSH INSET
DEPTH
1
1
/
4
"
(32)
NOTE: Dashed line represents prole of unit.
15
15
/
16
"
(405)
FLUSH INSET
HEIGHT
7
/
16
"
(11 )
3
/
4
"
(19)
ANTI-TIP BLOCK
A
TOP VIEW
E
FRONT ViEW
SIDE
VIEW
22"
(559)
OPENING
DEPTH
NOTE: All Microwave Drawer ovens require the same opening dimensions.
.
Dashed line represents prole of unit
.
14
3
/
4
"
(375)
OPENING
HEIGHT
ANTI-TIP BLOCK
W
OPENING WIDTH
TOP VIEW
BASE SUPPORT
30
1
/
8
"
(765)
22
1
/
8
"
(562)
4” (102)
21
7
/
8
"
(556)
BEHIND FRAME
15
1
/
8
"
(384)
29
7
/
8
"
(759)
21 /
8
"
(549)
POWER CORD
CHANNEL
1
1
/
4
"
(32)
4
5
/
8
"
(118)
1
3
/
4
"
(45)
14
5
/
8
"
(372)
16
1
/
2
"
(419)
OPEN DRAWER
Figure 2-4. 30” Microwave Drawer Dimensions
MD24 Specifications
Weight: 91 pounds.
Dimensions: 23-5/8” W x 15-1/8” H x 21-7/8” D.
Interior: 17-5/8” W x 7-1/8” H x 16-9/16” D.
Capacity: 1.2 cubic feet
MD30 Specifications
Weight: 96 pounds.
Dimensions: 29-7/8” W x 15-1/8” H x 21-7/8” D.
Interior: 17-5/8” W x 7-1/8” H x 16-9/16” D.
Capacity: 1.2 cubic feet
Page 10
TIMER
The Timer can be set for a maximum of 99 minutes and 99 seconds. Once a time is set, the countdown will
appear on the control panel display. Oven will chime and ‘END’ will appear on display when complete.
SET TIMER:
1. Touch TIMER.
2. Use number pads to enter timer duration. Up to 99 minutes and 99 seconds.
3. Touch TIMER again to begin.
4. Touch STOP/CLEAR to cancel.
USER OPERATION
CONTROL LOCK
Control Lock feature prevents unwanted microwave oven operation.
TO LOCK:
1. Touch CONTROL LOCK, then touch START. ‘LOCK ON’ will appear on control panel display.
TO UNLOCK:
1. Touch CONTROL LOCK, then touch START. ‘LOCK OFF’ will appear on control panel display.
SETTINGS
The Settings feature allows the user to select individual preferences. Preferences must be reset after a power fail-
ure.
AUDIBLE SIGNAL:
An audible signal will chime with every touch and upon cook time and timer completion.
To Eliminate Audible signal:
1. Touch SETTINGS twice
2. Touch START. ‘SOUND OFF’ will appear on the control panel display.
To Restore Audible signal:
1. Touch SETTINGS twice.
2. Touch START. ‘SOUND ON’ will appear on the control panel display.
COOK TIME COMPLETION REMINDER:
Upon completion, microwave oven will chime every ten seconds for first minute; then every three minutes (for one
hour) until STOP/CLEAR is touched.
To Eliminate Cook Time Completion Reminder:
1. Touch SETTINGS three times.
2. Touch START. ‘REMIND SIGNAL OFF’ will appear on control panel display.
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Theory of Operation
#824820 - Revision A - November, 2013 3-2
OPEN/CLOSE
To open or close drawer, touch OPEN/CLOSE. Do not push or pull drawer by hand, except in an emergency.
CLOCK
The clock must be set prior to use and after a power failure.
SETTING CLOCK:
1. Touch CLOCK.
2. Use the number pads to enter the time of day, then touch CLOCK.
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Theory of Operation
MD24 and MD30
#824820 - Revision A - November, 2013
3-3
MANUAL COOKING
POWER LEVEL
The microwave oven has ten preset power levels.
To cook manually at 100% Power:
1. Use number pads to enter desired cook time.
2. Touch START.
3. Oven will chime and ‘END’ will appear on control panel display when complete.
To cook manually at a Power level less than 100%:
1. Touch POWER LEVEL, then use number pads to select desired power level. Refer to chart below.
POWER LEVEL
POWER LEVEL 10 High 100%
POWER LEVEL, 9 90%
POWER LEVEL, 8 80%
POWER LEVEL, 7 Medium High 70%
POWER LEVEL, 6 60%
POWER LEVEL, 5 Medium 50%
POWER LEVEL, 4 40%
POWER LEVEL, 3 Medium Low/Defrost 30%
POWER LEVEL, 2 20%
POWER LEVEL, 1 Low 10%
To Restore Cook Time Completion Reminder:
1. Touch SETTINGS three times.
2. Touch START. ‘REMIND SIGNAL ON’ will appear on control panel display.
DEMONSTRATION MODE
Demonstration mode allows operation to be demonstrated without energizing the High Voltage circuit.
To enter Demonstration Mode:
1. Touch SETTINGS five times.
2. Touch START. ‘DEMO ON’ will appear on control panel display.
To exit Demonstration Mode:
1. Touch SETTINGS five times.
2. Touch START. ‘DEMO OFF’ will appear on control panel display.
MULTIPLE SEQUENCE COOKING
The microwave oven can be programmed for up to four automatic cooking sequences, switching from one power
level to another automatically.
To use Multiple Sequence cooking (e.g. start at 100%, then switch to 50% Power):
1. Touch POWER LEVEL twice, then use number pads to enter desired cook time.
2. Touch POWER LEVEL, then touch 5, then use number pads to enter a second cook time.
3. Touch START.
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Theory of Operation
#824820 - Revision A - November, 2013 3-4
AUTO START
The microwave oven can be programmed to begin cooking automatically at a designated time of day. The clock
must be set to correct time for Auto Start to function properly.
To use Auto Start:
1. Touch SETTINGS four times.
2. Touch START.
3. Use number pads to enter start time.
4. Touch CLOCK.
5. Use number pads to enter cook time. Adjust power level if necessary.
6. Touch START.
ADD MINUTE
The add minute feature cooks for one minute at 100% by touching ADD MINUTE. Touch multiple times to increase
cook time. Each touch increases time by one minute. This feature cannot be used with Sensor Cooking settings.
KEEP WARM
The keep warm feature will keep food warm for up to 90 minutes.
To use Keep Warm:
1. Touch KEEP WARM.
2. Use number pads to enter desired keep warm time.
3. Touch START.
4. Touch STOP/CLEAR to cancel.
POPCORN
The popcorn feature has two options. Follow directions on the control panel display to select desired option. Use
only popcorn packaged for microwave ovens.
To use Popcorn:
1. Touch POPCORN once for regular size or twice for snack size packages.
2. Touch START.
MELT
The melt feature will melt butter or chocolate.
To use Melt:
1. Touch MELT.
2. For butter: Touch 1 once for 2 tablespoons or twice for 1/2 cup.
3. For chocolate: Touch 2 once for 1 cup or twice for 1 square.
4. Touch START.
SOFTEN
The soften feature will soften ice cream or cream cheese.
To use Soften:
1. Touch SOFTEN.
2. For ice cream: Touch 1 once for 1 pint or twice for 1/2 gallon.
3. For cream cheese: Touch 2 once for 3 ounces or twice for 8 ounces.
4. Touch START.
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Theory of Operation
MD24 and MD30
3-5 #824820 - Revision A - November, 2013
BEVERAGE
The beverage feature will reheat a beverage or prepare hot water for coffee or tea.
To use Beverage:
1. Touch BEVERAGE.
2. To reheat beverage: Touch 1 multiple times to select amount in 1/2 cup increments, up to 2 cups.
3. For hot water: Touch 2 multiple times to select amount in 1 cup increments, up to 6 cups.
4. Touch START.
SENSOR COOKING
WOLF GOURMET
The Wolf Gourmet feature detects moisture and humidity from food as it heats and automatically adjusts cook time
and power level. Fresh vegetables and poultry have two options. Follow directions on the control panel display to
select the desired option. See Use and Care Guide for specific modes.
To select Wolf Gourmet:
1. Touch WOLF GOURMET, then use number pads to select desired food (e.g. 5 for baked potatoes).
2. Touch START.
SENSOR REHEAT
The sensor reheat feature detects moisture and humidity from food as it reheats, and automatically adjusts cook time
and power level.
To select Sensor Reheat:
1. Touch SENSOR REHEAT.
2. Touch START.
TIME ADJUSTMENT (sensor cooking settings)
The time adjustment feature increases or decreases cook time for sensor cooking settings.
To Adjust Time:
1. Touch POWER LEVEL once for ‘MORE’ or twice for ‘LESS’ time.
AUTO DEFROST
The auto defrost feature uses preset settings to defrost select food items. This is used for items listed in the Use
and Care Guide. For items not listed in Auto Defrost Guide in Use and Care manual see Manual Defrost.
To select Auto Defrost:
1. Touch AUTO DEFROST, then use number pads to select desired food (e.g. 3 for boneless poultry).
2. Use number pads to enter weight.
3. Touch START. After a period of time, microwave oven will stop so food can be checked.
4. Open drawer and turn food over.
5. Repeat until defrost is complete.
MANUAL DEFROST
The manual defrost feature automatically defrosts at 30% power. Food should be turned throughout the process to
ensure even defrosting. To defrost at another power level, refer to Power Level on page 3-3.
To use Manual Defrost:
1. Touch MANUAL DEFROST.
2. Use number pads to enter desired time.
3. Touch START.
Page 14
MD24 and MD30
Theory of Operation
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#824820 - Revision A - November, 2013
OFF CONDITION
Closing drawer activates door sensing switch and
secondary interlock switch. (Monitor switch contacts
are opened.) When oven is plugged in, 120 volts A.C.
is supplied to power unit.
1. Display will show flashing "Enjoy Your Drawer Touch
Clear and Touch Clock". To set any program or set
clock, you must first touch STOP/CLEAR pad. The dis-
play will clear, and " : " will appear.
COOKING CONDITION
Program desired cooking time by touching NUMBER
pads. Program power level by touching POWER
LEVEL pad and then a Number pad. When the
START pad is touched, the following operations occur:
1. Contacts of relays are closed and components
connected to relays are turned on as follows.
RELAY CONNECTED COMPONENTS
RY-1 Oven lamp
RY-2 Power transformer
RY-3 Stirrer motor
RY-4 Fan motor
2. 120 volts A.C. is supplied to primary winding of power
transformer and is converted to about 3.3 volts A.C.
output on the filament winding, and approximately
2370 volts A.C. on high voltage winding.
3. Filament winding voltage heats magnetron filament
and High Voltage winding sends voltage to voltage
doubler circuit.
4. Microwave energy produced by magnetron is chan-
nelled through waveguide into cavity feedbox, and
then into cavity where food is placed to be cooked.
5. Upon completion of cooking time, power transformer,
oven lamp, etc. are turned off, and generation of
microwave energy is stopped. Oven will revert to OFF
condition.
6. When drawer is opened during a cook cycle, monitor
switch, door sensing switch, secondary interlock
switch, relay (RY1) and primary interlock relay are
activated with following results. The circuits to the stir
fan motor, cooling fan motor, and high voltage compo-
nents are de-energized, oven lamp remains on, and
digital read-out displays time still remaining in cook
cycle when door was opened.
7. The monitor switch electrically monitors the operation
of secondary interlock switch and secondary interlock
relay and is mechanically associated with drawer so
that it will function in following sequence.
DESCRIPTION OF OPERATING SEQUENCE
8. When drawer opens from closed position, primary
interlock relay (RY2) and secondary interlock switch
open their contacts. Contacts of relay (RY1) remains
closed. Then monitor switch contacts close.
9. When the drawer is closed from open position, moni-
tor switch contacts open first. Then contacts of second-
ary interlock switch and door sensing switch close, and
contacts of the relay (RY1) open.
If secondary interlock switch and primary interlock relay
(RY2) fail with contacts closed when drawer is opened,
closing of monitor switch contacts will form a short circuit
through fuse, secondary interlock switch, relay (RY1)
and secondary interlock relay (RY2), causing fuse to
blow.
POWER LEVEL P-0 TO P-90 COOKING
When Variable Cooking Power is programmed, 120 volts
A.C. is supplied to power transformer intermittently
through contacts of relay (RY-2) which is operated by
power unit within a 32 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: ON/OFF time ratio does not correspond with
percentage of microwave power, because approx. 2
seconds are needed for heating of magnetron fila-
ment.
Page 15
Theory of Operation
MD24 and MD30
3-7 #824820 - Revision A - November, 2013
SENSOR COOKING CONDITION
Using SENSOR function, food is cooked without figur-
ing time, power level or quantity. When oven senses
enough steam from the food, it relays information to its
microprocessor which will calculate remaining cooking
time and power level needed for best results. When
food is cooked, water vapor is developed. Sensor
"senses" vapor and its resistance increases gradually.
When resistance reaches value set according to menu,
supplementary cooking is started. The time of supple-
mentary cooking is determined by experiment with
each food category and inputted into LSI.
Note: LSI - This is a microcomputer, responsible for
controlling the entire control unit.
Cooking Sequence:
1. Touch one of the SENSOR pads.
NOTE: The oven should not be operated on sensor
immediately after plugging in unit. Wait two min-
utes before cooking on SENSOR.
2. Coil of shut-off relay (RY-1) is energized, but power
transformer is not turned on.
3. After about 16 seconds, cook relay (RY-2) is ener-
gized. Power transformer is turned on, microwave
energy is produced and first stage is started. 16 sec-
onds is cooling time required to remove any vapor
from oven cavity and sensor.
NOTE: During this first stage, do not open drawer or
touch STOP/CLEAR pad.
4. When sensor detects vapor emitted from food, display
switches over to remaining cooking time and timer
counts down to zero. At this time, drawer may be
opened to stir, turn or season food.
5. When timer reaches zero, an audible signal sounds.
Shut-off relay and cook relay are de-energized and
power transformer, oven lamp, etc. are turned off.
6. Opening drawer or touching the STOP/CLEAR pad,
time of the day will reappear on display and oven will
revert to an OFF condition. When timer reaches zero,
an audible signal sounds.
Page 16
MD24 and MD30
Theory of Operation
3-8
#824820 - Revision A - November, 2013
Page 17
MD24 and MD30
Component Access
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#824820 - Revision A - November, 2013
COMPONENT ACCESS AND REMOVAL
This section explains how to adjust, access and remove components in a Microwave Drawer Oven. An attempt has
been made to arrange these procedures in such a way as to simulate which components would need to be removed
first in order to gain access to other components. When following a component removal procedure, it may be neces-
sary to reference another component removal procedures listed earlier in this section.
NOTE: Before continuing, please take note of the WARNINGS and CAUTION below.
HIGH VOLTAGE: MICROWAVE OVENS CONTAIN CIRCUITRY CAPABLE OF PRODUCING VERY HIGH VOLT-
AGE AND CURRENT. CONTACT WITH THE FOLLOWING COMPONENTS MAY RESULT IN SERIOUS PER-
SONAL INJURY OR DEATH:
• TRANSFORMER
• CAPACITOR
• RECTIFIER
• MAGNETRON
• HIGH VOLTAGE HARNESS
• BEFORE SERVICING MICROWAVE OVEN, THE CAPACITOR MUST BE DISCHARGED BY SHORTING THE
CONNECTING LEAD OF THE RECTIFIER AGAINST THE CHASSIS WITH AN INSULATED SCREWDRIVER.
FAILURE TO FOLLOW THIS STEP COULD RESULT IN SERIOUS PERSONAL INJURY OR DEATH.
• TO AVOID ELECTRIC SHOCK, POWER TO UNIT MUST BE DISCONNECTED WHENEVER ACCESSING
AND/OR REMOVING COMPONENTS POWERED BY ELECTRICITY OR COMPONENTS NEAR OTHER
ELECTRICAL COMPONENTS.
• BEFORE WIRING:
1. DISCONNECT POWER SUPPLY CORD, OPEN DRAWER, WAIT 60 SECONDS, THEN DISCHARGE THE
HIGH VOLTAGE CAPACITOR.
2. DON’T LET THE WIRE LEADS TOUCH TO THE FOLLOWING PARTS:
• HIGH VOLTAGE PARTS: MAGNETRON, HIGH VOLTAGE TRANSFORMER, HIGH VOLTAGE CAPACI-
TOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY.
• HOT PARTS: OVEN LAMP, MAGNETRON, HIGH VOLTAGE TRANSFORMER AND OVEN CAVITY.
• TO AVOID EXPOSURE TO MICROWAVES, NEVER OPERATE OR ALLOW DRAWER MICROWAVE TO BE
OPERATED WITH THE DRAWER OPEN. DO NOT OPERATE THE OVEN IF ANY OF THE FOLLOWING CON-
DITIONS EXIST:
1. DRAWER DOES NOT CLOSE FIRMLY.
2. DRAWER LATCH HOOK IS DAMAGED.
3. DRAWER GASKET OR SEAL IS DAMAGED
4. DRAWER IS BENT OR WARPED.
5. THERE ARE DEFECTIVE PARTS IN THE DRAWER INTERLOCK SYSTEM.
6. THERE ARE DEFECTIVE PARTS IN THE MICROWAVE GENERATING AND TRANSMISSION ASSEMBLY.
7. THERE IS VISIBLE DAMAGE TO THE OVEN.
• AFTER PERFORMING ANY REPAIR TO DOOR, DRAWER LATCH MECHANISM, OR DRAWER CLOSING
FACE, YOU MUST TEST INTEGRITY OF THE DRAWER SEAL WITH A MICROWAVE LEAK DETECTOR TO
VERIFY THERE ARE NO MICROWAVE LEAKS. (SEE PROCEDURES ON PAGE 4-3)
• IF NECESSARY TO REMOVE MICROWAVE OVEN FROM ITS INSTALLATION, REMEMBER THAT THE UNIT IS
HEAVY AND COULD TIP AND/OR FALL, RESULTING IN SERIOUS INJURY.
Be careful when handling sheet metal parts - Edges may be sharp.
NOTE: When all service work is completed and the oven is fully assembled, the microwave power output
should be checked and a microwave leakage test should be preformed and drawer interlock operation
checked.
Page 18
Component Access
MD24 and MD30
4-3 #824820 - Revision A - November, 2013
MICROWAVE MEASUREMENT PROCEDURE
1. Requirements:
A. 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/cm2 at
any point 5cm or more from the external surface of the oven.
B. Safety interlock switches: Primary interlock relay switch shall prevent microwave radiation emission in
excess of the requirement as above mentioned. Secondary interlock relay and door sensing switch shall pre-
vent microwave radiation emission in excess of 5 mW/cm2 at any point 5cm or more from the external surface
of the oven.
2. Preparation for testing: Before beginning the actual measurement of leakage, proceed as follows:
A. Make sure that the actual instrument is operating normally as specified in its instruction booklet.
NOTES:
•Survey instruments that comply with the requirement for instrumentation as prescribed by the perform-
ance standard for microwave ovens, 21 CFR 1030.0(c)(3)(i), must be used for testing.
•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.
B. Place a load of 275±15 ml (9.8 oz) of tap water initially at 20± 5C (68F) 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 non-conductive material such as glass or plastic. Placing of this standard load
in oven is important not only to protect oven, but also to insure that any leakage is measured accurately.
C. Set the cooking control on Full Power Cooking Mode.
D. Close drawer and select a cook cycle of several minutes. If water begins to boil before survey is completed,
replace it with 275 ml of cool water.
3. Leakage test: Closed-drawer leakage test (microwave measurement):
A. Grasp probe of survey instrument and hold it perpendicular to gap between drawer and the body of oven.
B. Move probe slowly, not faster than 1in./sec. (2.5 cm/sec.) along gap, watching for maximum indication on the
meter.
C. Check for leakage at drawer screen, sheet metal seams and other accessible positions where continuity of
metal has been breached (eg., around switches, indicator, and vents). While testing for leakage around draw-
er, pull drawer away from the front of oven as far as is permitted by the closed latch assembly.
D. Measure carefully at point of highest leakage and make sure that highest leakage is no greater than
4mW/cm2, and that primary interlock switch/secondary interlock relay does turn oven OFF before any drawer
movement.
BEFORE OPERATING OVEN AFTER SERVICE
1. Disconnect power supply cord.
2. Make sure that a definite ”click” can be heard when microwave oven drawer is unlatched. (Hold drawer in a
closed position with one hand, then pull drawer open, this causes latch leads to rise, it is then possible to hear a
“click’ as the drawer switches operate.)
3. Visually check drawer and cavity face plate for damage (dents, cracks, signs of arcing etc.).
Do not operate oven if any of the following conditions exist:
• Drawer does not close firmly.
• Drawer latch hook is damaged.
• Drawer gasket or seal is damaged.
• Drawer is bent or warped.
• There are defective parts in drawer interlock system.
• There are defective parts in microwave generating and transmission assembly.
• There is visible damage to oven.
Do not operate oven without the RF gasket (Magnetron); if wave guide or oven cavity are not intact; if drawer is
not closed.
Page 19
MD24 and MD30
Component Access
4-4
#824820 - Revision A - November, 2013
Emergency Opening of Drawer:
If unit is flush mounted and drawer is not opening use
one of following procedures.
1.Use an angled screw driver or allen key wrench and
insert it under bottom middle of drawer to grab the vent
opening at bottom of drawer and carefully pull drawer
open.
2.Use a strong suction cup placed on center of drawer.
Un-installing the Microwave Drawer:
1.Open Microwave Drawer and extract four mounting
screws holding unit on to wall or cabinet opening.
(See Figure 4-1).
Mounting Screws Mounting Screws
Figure 4-1. Mounting Screw Locations
2.Close Microwave Drawer and carefully pull unit out
from opening.
3.Unplug power supply cord.
4.Place Microwave Drawer on secured working surface.
Removing Cord and Outer Case:
1.Extract two screws holding AC Cord Mounting Angle.
Lift mounting angle with AC Cord attached and unplug
AC Cord from molex. (See Figure 4-2).
2.Extract eighteen (18) screws holding the Outer
Case/Side Angles, and latch cover plates.
3.Remove Outer Case. (See Figure 4-2).
AC Cord
Mount Angle
AC Cord
Cord Bushing
Side Angle
Outer Case
Schematic Diagram
Side Angle
Latch Cover Plates
Knockout for Oven Lamp Replacement
Figure 4-2. AC Cord/Outer Case Removal
Accessing Rear Components:
1.Extract ten screws holding Back Cover. (See Figure 4-
3).
Cavity
Back cover
Door Panel
Door
Frame
Assy
Figure 4-3. Back Cover Screws
Metal Key Unit Frame Assembly
1.Remove two side angles.
2.Carefully unsnap Frame Assembly by lifting up and tilt-
ing forward.
3.Be sure and unplug Power Supply Board cable before
lifting off. (See Figure 4-4)
NOTE: when lifting off Metal Key Unit Frame - ground
spring will be loose.
4.Removing Control panel frame will allow access to
Control Board.
NOTE: Metal Key Unit Assembly is held by right & left
side angles. There are also three clips at top and bottom
that snap into cavity faceplate.
Figure 4-4. Metal Key Unit Frame
CPU Board
CPU screws
GND Spring
Page 20
Component Access
MD24 and MD30
4-5 #824820 - Revision A - November, 2013
Noise Filter Board Replacement
1.Disconnect Black and White wire from Noise Filter
Board. (See Figure 4-5).
2.Extract screw from Noise Filter Board.
3.Remove Noise Filter Board.
Red WireRed Wire
ScrewScrew
DoubleDouble
WhiteWhite
Noise Filter BoardNoise Filter Board
Black WireBlack Wire
White WireWhite Wire
Figure 4-5. Noise Filter Board
Latch Hook and Microswitch Removal
1.Follow Microwave Drawer disassembly as previously
stated.
2.Open drawer and keep it open.
3.To discharge high voltage capacitor, wait for 60 sec-
onds.
4.Disconnect wire leads from each switch.
5.Extract screw holding latch hook to oven flange.
6.Remove latch hook from oven flange.
7.Remove each switch from latch hook by pushing the
one stopper tab holding each switch.
NOTEote: Assure continuity of the Monitor circuit when
reinstalling monitor switch or right side Latch Hook
Assembly.
Adjusting Monitor, Stop, and Secondary Interlock Switches
1.Follow Microwave Drawer disassembly as previously
stated.
2.Open drawer and keep it open.
3.To discharge high voltage capacitor, wait for 60 sec-
onds.
4.If door sensing, third door, secondary interlock and
monitor switch do not operate properly due to a misad-
justment, the following adjustment should be made.
5.Loosen screw holding latch hook to oven cavity flange.
6. With drawer closed, adjust latch hook by moving it
back and forth, and up and down. In and out play of
drawer allowed by upper and lower position of latch
hook should be less than 0.5mm. Vertical position of
latch hook should be adjusted so that secondary inter-
lock switch is activated with drawer closed.
7. Horizontal position of latch hook should be adjusted
so that monitor switch and drawer sensing switch are
activated with drawer closed.
8. Secure screws with washers firmly.
9. Check all switch operation.
(See Figure 4-6 and Figure 4-7).
Third Door Switch
Door Sensing Swtich
Figure 4-6. Left side Latch Hook
Monitor SwtichMonitor Swtich
Secondary Interlock SwtichSecondary Interlock Swtich
Figure 4-7. Right side Latch Hook
This manual suits for next models
3
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