Whirlpool 721.663398 User Manual

MODEL 721.66339
DIVISION 20
BASIC FIELD MANUAL
FOR
MICROWAVE OVEN
MODEL 721.66339800
February, 2008
WARNING TO SERVICE TECHNICIANS
PRECAUTIONS TO BE OBSERVED BEFORE
AND DURING SERVICING TO AVOID
POSSIBLE EXPOSURE TO EXCESSIVE
MICROWAVE ENERGY
a. Do not operate or allow the oven to be operated with the door open. b. Make the following safety checks on all ovens to be serviced before activating the magnetron or other
microwave source, and make repairs as necessary; (1) Interlock operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and latches, (5) evidence of dropping or abuse.
c. Before turning on microwave for any service test or inspection within the microwave generating
compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment, integrity, and connections.
d. Any defective or misadjusted components in the interlock, monitor, door seal, and microwave
generation and transmission systems shall be repaired 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.
• Proper operation of the microwave ovens requires that the magnetron be assembled to the wave guide and cavity. Never operate the magnetron unless it is properly installed.
• Be sure that the magnetron gasket is properly installed around the dome of the tube whenever installing the magnetron.
• Routine service safety procedures should be exercised at all times.
• Untrained personnel should not attempt service without a thorough review of the test procedures and safety information contained in this manual.
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FOREWORD
Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing yourself to the Microwave Energy normally contained within the oven cavity.
MODEL 721.66339
MECHANICAL SERVICE INFORMATION
TABLE OF CONTENTS
1. Adjustment Procedures
2. Precautions on Installation
3. General Precautions in Use
4. Trial Operation
5. Specifications
6. Overall Circuit Diagram
7. Operating Procedures
8. Procedure for Measuring Microwave Energy Leakage
9. Disassembly Instructions
10. Interlock Continuity Test
11. Test and Checkout Procedures, and Troubleshooting
A. Test Procedures
B. Checkout Procedures
C. Troubleshooting
12. Exploded view
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3
5
5
5
6
7-8
9-10
11-12
13-17
18
19-21
22-24
25-29
30-37
13. Part Reference list
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38-39
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1. ADJUSTMENT PROCEDURES
To avoid possible exposure to microwave energy leakage, adjust the door latches and interlock switches, using the following procedure.
ONLY AUTHORIZED SERVICE PERSONNEL SHOULD MAKE THIS ADJUSTMENT.
The Interlock Monitor and Primary Interlock Switch acts as the final safety switch protecting the user from microwave energy. The terminals between “COM” and “NC” of the Interlock Monitor must close when the door is opened. After adjusting the Interlock Monitor Switch, make sure that it is correctly connected. See Figures 1-a and 1-b throughout this procedure.
CHECK THE DOOR LATCH AND SWITCH CLOSING.
NOTE: The outer cover of the microwave oven is
removed.
(1) Set the microwave oven on its side so that you can see
the latch board and the switches, as shown in Figure 1-a.
(2) Close the door tightly and check gaps A and B to be
sure they are no more than 1/64(0.5 mm). See Figure
1-b for close-up view of gaps A and B (door latches). If all gaps are less than 1/64(0.5 mm), adjustment of the latch board may not be necessary. Go to Steps 5 and 6 to check the sequence of the switches.
NOTE: To correct sequence of the Primary Interlock
Switch, Secondary Interlock Switch and the Interlock Monitor Switch is very important.
If any gap is larger than 1/64(0.5 mm), you will need to adjust the latch board-U, L. Go to step 3 and follow all steps in order.
ADJUST THE LATCH AND SWITCH CLOSING
(3) Loosen the two screws holding the plastic latch board as
shown.
(4) With the oven door closed tightly, move the latch board
upward toward the top of the oven and/or away from the door latch until the gaps are less than 1/64(0.5 mm).
Hold the latch board tightly in this position until you check the sequence of the switches in steps 5 and 6.
TEST THE LATCH AND SWITCH SEQUENCE
(5) Open the oven door slowly. Watch the door latch, the
Primary Switch. Release Rod and Lever on the switches to make sure they are zero to the body of the switches in the following sequence:
- Primary Interlock Switch
- Secondary Interlock Switch
- Interlock Monitor Switch
Adjust the latch board until the switches operate in this sequence. See Steps 3 and 4.
(6) Close the oven door slowly and be sure it is tightly
closed. Watch the three switches to make sure they are zero to the body of the switches in the following sequence:
- Interlock Monitor Switch
- Primary Interlock Switch
- Secondary Interlock Switch
NOTE: The Interlock Monitor Switch is an added safety
check on the Primary and Secondary Interlock Switches. If the Primary and Secondary Interlock Switches allow the oven to operate with the door open, the Monitor Switch will blow the fuse.
(7) When you achieve the proper sequence of switches in
Steps 5 and 6, tighten the latch board screws at that point.
TEST THE MICROWAVE ENERGY LEAKAGE
(8) Using a survey meter, make sure the microwave energy
is below 5 mW/cm.sq.
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LATCH BOARD
DOOR LATCH
A
SECONDARY INTERLOCK SWITCH
MONITOR INTERLOCK SWITCH
DOOR LATCH
LATCH BOARD
0-1/64"
LATCH
0-1/64"
PRIMARY INTERLOCK SWITCH
Figure 1-a
Figure 1-b
2. PRECAUTIONS ON INSTALLATION
(Figure 2)
A. Plug the power supply cord into a 120 V AC, 60 Hz,
single-phase power source with a capacity of at least 20 amperes.
B. Since the unit weights about 36.5 lbs, be sure to place it
on a sturdy and flat surface.
C. Avoid placing the unit in a location where there is direct
heat or splashing water.
D. Place the unit as far away as possible from TV, radio,
etc. to prevent interference.
CAUTION
3. GENERAL PRECAUTIONS IN USE
A. Never operate the unit when it is empty. Operating the
oven with no load may shorten the life of the magnetron. Whenever cooking dry foods (dried fish, bread, etc.) or a small amount of food, be sure to put a glass of water into the cooking compartment. The turntable tray may become hot after operating, be careful when touching it.
B. Aluminum foil should be avoided because it will disrupt
cooking and may cause arcing. However, small pieces may be used to cover some parts of food to slow the cooking. Any aluminum foil used should never be closer than 2.5 cm to any side wall of the oven.
4. TRIAL OPERATION
After installation, the following sequences and results should be checked carefully. A. Put a container filled with water (about 1 liter) into the
oven, and close the door tightly. B. Touch the STOP/CLEAR and the COOK TIME keys. C. Set cooking time for 10 minutes by touching “1”
and then “0” three times. 1000 appears in the
display window. D. Touch the START key.
Make sure the cavity light comes on. The unit will begin
cooking and the display window will show the time
counting down by seconds. E. After about 5 minutes, make sure the primary interlock
switch, the secondary interlock switch and the interlock
monitor and oven lamp switch operate properly by
opening and closing the door several times. Touch the
START key each time the door is closed. F. Continue operating the unit. Four long beep sound
signal is heard when the time is up. The unit will shut off
automatically. G. Confirm the water is hot. H. Finally, measure the output power according to
POWER OUTPUT MEASUREMENT on page 12.
5. FEATURES AND SPECIFICATIONS
A. The safety systems incorporated in this model are:
(1) Primary interlock switch
(2) Secondary interlock switch
(3) Interlock monitor switch
(4) Choke system
(5) Thermostat
(Note: This thermostat located on the oven cavity will open and stop the unit from operation only if a high temperature is reached, such as, a fire created by overcooking food.)
B. Any one of 10 power output levels ranging 120W to
1200W can be selected by the touch control and
electronic computer system. C. Cooking time can be displayed on the digital readout. D. Three different cooking stages can be set. The oven
remembers three cooking stages and changes from one
cooking stage to another. This is made possible with the
memory function of the microprocessor.
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This unit is equipped with a 3-prong plug for your safety. If the wall outlet is a grounded 3-hole type, the unit will be grounded automatically.
Three-Pronged(Grounding) Plug
Figure 2
Properly Polarized and Grounded Outlet
SPECIFICATIONS
Rated Power Consumption..........................................1650W maximum
Output
..........................................................................1200W maximum (*IEC 60705 Rating standard)
...................................................................Adjustable 100W through 1200W, 11 steps
Frequency....................................................................2,450 MHz ± 50 MHz
Power Supply...............................................................120V ±12V AC, 60Hz
Rated Current...............................................................13.8 Amp.
Magnetron Cooling.......................................................Forced Air Cooling
Microwave Stirring........................................................Turntable
Rectification..................................................................Rectification Voltage Doubler Half-Wave
Door Sealing ................................................................Choke System
Safety Devices.............................................................Thermostat:
Open at 90°C ± 5°C
Open at 75°C ± 5°C Fuse(15A) Primary Interlock Switch Secondary Interlock Switch Interlock Monitor
Magnetron....................................................................2M246
High Voltage Capacitor................................................Capacitor: 1.05µF, 2.1KV Ac
High Voltage Diode......................................................350mA, 9.0KV
Cavity Lamp.................................................................125V, 20W
Timer............................................................................Digital, up to 99 mm. 99 sec. (in each cooking stage)
Tray..............................................................................Tempered Safety Glass
Overall Dimensions......................................................21
7
/18”(W) x 121/2”(H) x 171/8”(D)
Oven Cavity Size..........................................................14
11
/16”(W) x 95/8”(H) x 155/8”(D)
Effective Capacity of Oven Cavity................................1.2 Cu.ft.
Accessories..................................................................Use and Care Manual ,Turntable,
Rotating Ring Assembly.
SWITCH TABLE
NOTE: Use the above switch table with circuit diagram on page 7.
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PRIMARY SECONDARY INTERLOCK INTERLOCK INTERLOCK MONITOR SWITCH SWITCH SWITCH
COM COM COM
NO NO NC
SWITCH MODE
CONDITIONS
DOOR OPEN
DOOR CLOSED
∞∞∞0
0
0
IMPORTANT SAFETY NOTE: THE SHADED AREAS ON THIS SCHEMATIC DIAGRAM INCORPORATE SPECIAL FEATURES
IMPORTANT FOR PROTECTION FROM MICROWAVE RADIATION, FIRE, ELECTRICAL SHOCK, AND
HAZARDS. WHEN SERVICING IT IS ESSENTIAL THAT ONLY MANUFACTURER S SPECIFIED PARTS
BE USED FOR THE CRITICAL COMPONENTS IN THE SHADED AREAS OF THE SCHEMATIC DIAGRAM.
NOTICE: SINCE THIS IS BASIC SCHEMATIC DIAGRAM, THE VALUES OF COMPONENTS AND
SOME PARTIAL CONNECTIONS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.
6. OVERALL CIRCUIT DIAGRAM A. SCHEMATIC DIAGRAM
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B. MATRIX CIRCUIT FOR TOUCH KEY BOARD
-8-
Figure 4
7. OPERATING PROCEDURES A. OVEN CONTROL PANEL
Figure 5
1. DISPLAY. The display includes a clock and indicators that tell you
time of day, cooking time settings, and cooking functions selected.
2. QUICK TOUCH SENSOR. This pad allows you to cook most of
your favorite foods without having to select cooking times and power levels.
3. MORE / LESS. All of the one touch cook and Timed Cook can be
adjusted to cook food for a longer or shorter time. MORE Press MORE will add 10 seconds to the cooking time. LESS Press LESS will subtract 10 seconds to the cooking time.
4. AUTO DEFROST. This pad is an accurate defrosting method for
frozen meat, poultry and fish up to 6.0 lbs.
5. TrueCookPlus®. Touch this pad to cook food according to
TrueCookPlus®code.
6. NUMBER PADS. Touch Number Pads to enter cooking time,
power level, quantities, or food categories.
7. COOK TIME. Touch this pad to set a cooking time.
8. STOP/CLEAR. Touch this pad to stop the oven or clear entries.
9. EXPRESS DEFROST. This pad provides you with the quick
defrosting method for 1.0 pound frozen foods.
10. MELT. Touch this pad to melt chocolate, cheese, butter, or
marshmallows.
11. SOFTEN. Touch this pad to soften ice cream, cream cheese,
butter, or frozen juice.
12. AUTO COOK. Touch this pad to select programming food items.
13. KITCHEN TIMER. Touch this pad to use your microwave oven as
a kitchen timer.
14. CLOCK. Touch this pad to enter the time of day.
15. OPTION. Touch this pad to change the oven's default settings for
sound, clock, scroll speed and weight.
16. POWER. Touch this pad to set a cooking power.
17. ADD MINUTE. Touch this pad to cook at 100% cook power for
1 minute to 99 minutes and 59 seconds.
18. START. Touch this pad to start all entries (except the Quick
Touch Sensor, Express Defrost, Auto Cook and Add Minute function which start automatically) and to turn Child Lock on or off.
NOTE: A “beep” sounds when you touch a “key” on the control panel, to indicate that you have entered
a setting.
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B. EASY USE TABLE
(1) KITCHEN TIMER
1. Touch STOP/CLEAR.
2. Touch KITCHEN TIMER.
3. Touch correct number for time.
4. Touch START.
(2) CHILD LOCK
To set:
1. Touch STOP/CLEAR.
2. Touch START more than 4 seconds. To cancel:
1. Touch STOP/CLEAR.
2. Touch START more than 4 seconds.
(3) SENSOR COOK
1. Touch STOP/CLEAR.
2. Touch SENSOR COOK Category.
(4) ADD MINUTE
1. Touch STOP/CLEAR.
2. Touch ADD MINUTE.
(5) AUTO DEFROST
1. Touch STOP/CLEAR.
2. Touch AUTO DEFROST. Three different defrosting levels are provided. (Touch 1 : Meat
Touch 2 : Poultry Touch 3 : Fish)
3. Enter the weight of your food in decimal increments from 0.1 to 6.0 pounds.
4. Touch START
5. At beeping, turn food over.
6. After turning food over, touch START to resume defrosting.
(6) TIMED COOKING
1. Touch STOP/CLEAR.
2. Touch COOK TIME.
3. Touch number for cooking time.
4. Touch POWER.
5. Touch number for cooking power level.
6. Touch START.
(7) MULTI-STAGE COOKING
1. Touch STOP/CLEAR.
2. Touch COOK TIME.
3. Touch number for cooking time.
4. Touch POWER.
5. Touch number for cooking power level.
6. Repeat steps 2-5 to set 2nd cooking stage.
7. Touch START.
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8. PROCEDURE FOR MEASURING MICROWAVE ENERGY LEAKAGE
A. CAUTIONS
(1) Be sure to check a microwave emission prior to servicing
the oven if the oven is operative prior to servicing.
(2) The service personnel should inform the manufacturer,
importer, or assembler of any certified oven unit found to have a microwave emission level in excess of 5mW/cm.sq. and should repair any unit found to have excessive emission levels at no cost to the owner and should ascertain the cause of the excessive leakage. The service personnel should instruct the owner not to use the unit until the oven has been brought into compliance.
(3) If the oven operates with the door open, the service
personnel should;
- Tell the user not to operate the oven
- Contact the manufacturer and CDRH (Center for Devices and Radiological Health) immediately. NOTE: Address on CDRH Office of Compliance (HFZ-312) Center for Devices and Radiological Health 1390 Piccard Drive Rockville, Maryland 20850
(4) The service personnel should check all surface and vent
openings for microwave emission testing.
(5) Check for microwave energy leakage after every
servicing. The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 1mW/cm.sq. And always start measuring of an unknown field to assure safety for operating personnel from radiation leakage. NOTE: The standard is 5mW/cm.sq. while in the customer’s home. 1mW/cm.sq. stated here is manufacturer’s own voluntary standard for units in customer’s home.
EQUIPMENT
• Electromagnetic energy leakage monitor (NARDA 8100B, HOLADAY HI 1501)
• 600cc glass beaker
• Glass thermometer 100°C
B. MEASURING MICROWAVE ENERGY LEAKAGE
(1) Pour 275±15cc of 20±5°C water in a beaker which is
graduated to 600 cc, and place the beaker in the center of the oven.
(2) Set the energy leakage monitor to 2,450 MHz and use it
following the manufacturer’s recommended test procedure to assure correct result.
(3) When measuring the leakage, always use the 2 inch
(5cm) spacer supplied with the probe. (4) Operate the oven at its maximum output. (5) Measure the microwave radiation using and
electromagnetic radiation monitor by holding the probe
perpendicular to the surface being measured. (See
Figure 7)
C. MEASUREMENT WITH THE OUTER CASE REMOVED
(1) When you replace the magnetron, measure for
microwave energy leakage before the outer case is
installed and after all necessary components are
replaced or adjusted. Special care should be taken in
measuring the following parts.
- Around the magnetron
- The waveguide
WARNING: AVOID CONTACTING ANY HIGH VOLTAGE
PARTS.
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Move probe along shaded area.
Probe scanning speed less than 2.5 cm/sec.
Figure 7
Figure 6
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