Sharp R-2397 service manual Operation Sequence, OFF Condition, Microwave Cooking Condition

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R-2397

OPERATION SEQUENCE

OFF CONDITION

Closing the door activates all door interlock switches

(1st latch switch, 2nd latch switch, 3rd latch switch and stop switch)

IMPORTANT

When the oven door is closed, the monitor switch contacts COM-NC must be open. When the microwave oven is plugged in a wall outlet (230 volts, 50Hz), the line voltage is supplied to the point A5+A7 in the control panel.

Figure O-1 on page 30

1. The digital display shows .

NOTE: When the door is opened or after cooking, oven lamp, blower motor and stirrer motors work for 1 minute.

MICROWAVE COOKING CONDITION

Touch MANUAL/ REPEAT key and enter a desired cooking time with the touching NUMBER key. And then touch START key.

Function sequence Figure O-2 on page 30

CONNECTED COMPONENTS

RELAY

Oven lamp/ Blower motor/ Stirrer motors

RY1

 

 

Power transformer (rear)

RY3

 

 

Power transformer (front)

RY4

 

 

1.The line voltage is supplied to the primary winding of the high voltage transformer. The voltage is converted to about 3.3 volts A.C. output on the filament winding and high voltage of approximately 2000 volts A.C. on the secondary winding.

2.The filament winding voltage (3.3 volts) heats the magnetron filament and the high voltage (2000 volts) is sent to the voltage doubling circuit, where it is doubled to negative voltage of approximately 4000 volts D.C..

3.The 2450 MHz microwave energy produced in the magnetron generates a wave length of 12.24 cm. This energy is channelled through the waveguide (transport channel) into the oven cavity, where the food is placed to be cooked.

4.When the cooking time is up, a signal tone is heard and the relays RY3+RY4 go back to their home position. The circuits to the high voltage transformers. The relay RY1 remains and oven lamp, blower motor and stirrer motors work for 1 minute.

5.When the door is opened during a cook cycle, the switches come to the following condition.

 

 

CONDITION

 

 

DURING

DOOR OPEN

SWITCH

CONTACT

COOKING

(NO COOKING)

 

 

 

 

1st latch switch

COM-NO

Closed

Open

 

 

 

 

Monitor switch

COM-NC

Open

Closed

 

 

 

 

2nd latch switch

COM-NO

Closed

Open

 

 

 

 

Stop switch

COM-NO

Closed

Open

 

 

 

 

3rd latch switch

COM-NO

Closed

Open

the relay RY1 stays closed. Shown in the display is the remaining time, but the program is cancelled if the oven is not started within 3 minutes.

6. MONITOR SWITCH CIRCUIT

The monitor switch is mechanically controlled by oven door, and monitors the operation of the 1st latch switch.

6-1. When the oven door is opened during or after the cycle of a cooking program, the 1st, 2nd, 3rd latch and stop switches must open their contacts first. After that the contacts (COM-NC) of the monitor switch can be closed.

6-2. When the oven door is closed, the contacts (COM-NC) of the monitor switch must be opened first. After that the contacts (COM-NO) of the 1st, 2nd, 3rd latch and stop switches must be closed.

6-3. When the oven door is opened and the contacts of the 1st latch switch remain closed, remains closed, the fuse F6.3A will blow, because the monitor switch is closed and a short circuit is caused.

MICROWAVE VARIABLE COOKING

When the microwave oven is preset for variable cooking power, the line voltage is supplied to the high voltage transformers intermittently within a 48 second time base through the contacts of the relays RY3+RY4.

The following levels of microwaves power are given.

48 sec. ON

Number key

44sec. ON

Number key 9

40 sec. ON

Number key 8

36 sec. ON

Number key 7

32 sec. ON

Number key 6

26 sec. ON

Number key 5

22 sec. ON

Number key 4

16 sec. ON

Number key 3

12 sec. ON

Number key 2

8 sec. ON

Number key 1

0 sec. ON

Number key 0

NOTE: The ON/OFF time ratio does not exactly corre- spond to the percentage of microwave power, be- cause approx. 3 seconds are needed for heating up the magnetron filament.

TWO MAGNETRON OPERATION SYSTEM

The circuits to the high voltage transformers are cut off when the 1st latch, 2nd latch, 3rd latch and stop switches are made open. The blower motor, stirrer motors and oven lamp remains on even if the oven door is opened after the cooking cycle has been interrupted, because

Two magnetrons MG1+MG2 are equipped in order to get higher microwave power output. The primary windings of the high voltage transformers T1+T2 are connected so that each magnetron can be oscillated alternatively according to the frequency of the power supply. Refer to the Figure 1 and 2.

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Contents Table of Contents Commercial Microwave Oven2397 2397 Sharp Corporation OSAKA, JapanCommercial General Important InformationGeneral Information SpecificationProduct Description DescriptionAppearance View Installation InformationDisplay and Indicators Operating KeysMicrowave Cooking Condition Operation SequenceOFF Condition Microwave Variable CookingFunction of Important Components Intake Thermistor Asymmetric RectifierExhaust Thermistor Magnetron ThermistorRemember to Check 3D Troubleshooting GuideServicing Remember to Check 4RTest Procedure Possible Cause Defective Parts Plugged into wall outletTemperature of Intake Thermistor is High Microwave Output Power IEC-705-1988 Test ProceduresProcedure Component Test Letter Magnetron Test Around 20 C Power supply Voltage Rated voltageCarry OUT 3D Checks Procedure Letter Component TestHigh Voltage Transformer Test Carry OUT 4R ChecksHigh Voltage Capacitor Test Carry OUT 3D Checks Procedure Component Test LetterSwitch Test Weak Point A018Table Thermal Cut-out Test Fuse F6.3A TestThermal CUT-OUT Test Carry OUT 3D Checks Monitor Resistor Test Carry OUT 3D ChecksIntake Thermistor Test Procedure Component Test Letter Magnetron Thermistor TestExhaust Thermistor Test Motor Winding TestTouch Control Panel Assembly Test Min Cx ± 20% Cy ± 20% 5mHKEY Unit Test Relay Test Test Procedures ContdTo determine if the control unit or key pad is at fault CircuityStop Switch Circuit Power Supply CircuitPower Sync Signal Generating Circuit Exhaust Air Temperature Detecting CircuitDescription of LSI LSIIZA646DR Power source voltage Pin No Signal DescriptionInternal clock oscillation frequency setting input Signal coming from touch keySound Voltage level control terminal Shapes of Electronic Components Other PrecautionsServicing Servicing of Touch Control PanelProcedure for Entering to IC-2 Practice for checking total service counts eg 234,567 CountsTo check the contents of defrost Flicker / 0.1 sec Buzzer Other Checking and Clearing PRO CedureHigh Voltage Components Removal Component Replacement and Adjustment ProcedureOuter Case Removal To remove the components, proceed as followsBlower Motor Removal Magnetron RemovalHigh Voltage Transformer Removal Stirrer Motor Upper RemovalControl Panel Assembly Removal Control Panel Assembly and Control Unit RemovalHOW to Release the Positive Lock Connector ProcedurePower Supply Cord Replacement Re-installAfter adjustment, make sure of the following Door Adjustment Door Replacement and AdjustmentDoor Replacement Choke Cover RemovalMicrowave Measurement Service InformationPreparation for Testing RequirementFigure O-1. Oven SChematic-OFF Condition High Voltage Components Circuit C d eFigure S-3. Printed Wiring Board Electric Parts Parts ListParts marked * are used in voltage more than Cabinet PartsVCEAB31HW104M Oven Parts Door PartsMiscellaneous SCRE, Nuts and WashersREF. no HOW to Order Replacement PartsModel Number DescriptionOven and Cabinet Parts Control Panel Parts Door Parts Not replaceable items 2397

R-2397 specifications

The Sharp R-2397 is a high-performance microwave oven that combines advanced technology with user-friendly features, making it a popular choice for modern kitchens. This model stands out due to its sleek design and efficient functionality, catering to both cooking enthusiasts and busy households alike.

One of the most notable features of the Sharp R-2397 is its powerful microwave cooking capabilities. With a wattage rating of 900 watts, it ensures that food is cooked evenly and quickly, allowing users to prepare meals in a fraction of the time compared to conventional ovens. The unit also offers multiple power levels, enabling precise cooking adjustments for various types of food, from defrosting to reheating and everything in between.

Another key characteristic of the R-2397 is its spacious interior. With a generous capacity of 23 liters, this microwave can accommodate larger dishes, making it suitable for families or individuals who enjoy hosting gatherings. The turntable feature promotes even cooking by rotating food continuously, ensuring that every inch is heated uniformly.

Additionally, the Sharp R-2397 is equipped with a range of convenient presets and auto-cook functions. These pre-programmed settings allow users to optimize cooking times for common dishes, such as popcorn, vegetables, and frozen meals, simplifying meal preparation and enhancing user experience. The intuitive control panel is designed to be user-friendly, ensuring that anyone can operate the microwave with ease.

Safety is also a significant consideration in the design of the Sharp R-2397. The unit comes with a child lock function, preventing accidental operation and ensuring that the oven is used safely in households with young children. This feature adds peace of mind for parents while using the appliance in their daily routines.

Moreover, the R-2397 incorporates a modern aesthetic that can fit into various kitchen styles. Its polished exterior and compact design make it both attractive and practical, with the added advantage of easy cleaning and maintenance.

In summary, the Sharp R-2397 is a versatile microwave oven that offers a blend of power, efficiency, and user-centric features. With its high wattage, spacious interior, smart presets, and safety measures, it is an excellent addition to any kitchen, catering to everyday cooking needs and helping to simplify meal times. Whether reheating leftovers or cooking a new recipe, the Sharp R-2397 sets itself apart as a reliable kitchen companion.
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