Sharp R-2397 service manual Test Procedures, Procedure Component Test Letter Magnetron Test

Page 12

R-2397

TEST PROCEDURES

PROCEDURE

COMPONENT TEST

LETTER

AMAGNETRON TEST

NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION.

CARRY OUT 3D CHECK.

Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.

To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron filament terminals, the meter should show a reading of less than 1 ohm.

To test for short filament to anode condition, connect ohmmeter between one of the filament terminals and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low or zero resistance reading is obtained then the magnetron should be replaced.

MICROWAVE OUTPUT POWER (IEC-705-1988)

The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case fitted). Microwave output power from the magnetron can be measured by way of IEC 705, i.e. It is measured by how much power the water load can absorb. To measure the microwave output power in the microwave oven, the relation of calorie and watt is used. When P(W) heating works for t(second), approximately P x t/4.187 calorie is generated. On the other hand, if the temperature of the water with V(ml) rises ΔT (°C) during this microwave heating period, the calorie of the water is V x ΔT.

The formula is as follows;

 

 

 

 

 

P x t / 4.187 = V x Δ T

 

P (W) = 4.187 x V x ΔT / t

 

 

Our condition for water load is as follows:

 

 

Room temperature

around 20°C Power supply Voltage

Rated voltage

Water load

 

1000 g

Initial temperature

10±2°C

 

Heating time

25 sec.

P=170xΔT

 

 

Measuring condition:

1.Container

The water container must be a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190 mm.

2.Temperature of the oven and vessel

The oven and the empty vessel are at ambient temperature prior to the start the test.

3.Temperature of the water

The initial temperature of the water is (10±2)°C.

4.Select the initial and final water temperature so that the maximum difference between the final water temperature and the ambient temperature is 5K.

5.Select stirring devices and measuring instruments in order to minimize addition or removal of heat.

6.The graduation of the thermometer must be scaled by 0.1°C at minimum and can be accurate thermometer.

7.The water load must be (1000±5) g.

8.“t” is measured while the microwave generator is operating at full power. Magnetron filament heat-up time is not included.

NOTE: The operation time of the microwave oven is “t + 3” sec. (3 sec. is magnetron filament heat- up time.) Therefore total reheating time = 28 seconds.

Measuring method:

1.Measure the initial temperature of the water before the water is added to the vessel. (Example: The initial temperature T1 = 11°C)

2.Add the 1 litre water to the vessel.

3.Place the load on the centre of the shelf.

4.Operate the microwave oven at HIGH for the temperature of the water rises by a value Δ T of (10 ± 2) K.

5.Stir the water to equalize temperature throughout the vessel.

6.Measure the final water temperature. (Example: The final temperature T2 = 21°C)

7.Calculate the microwave power output P in watts from above formula.

10

Image 12
Contents Table of Contents Commercial Microwave Oven2397 Sharp Corporation OSAKA, Japan Commercial2397 General Important InformationSpecification Product DescriptionGeneral Information DescriptionInstallation Information Display and IndicatorsAppearance View Operating KeysOperation Sequence OFF ConditionMicrowave Cooking Condition Microwave Variable CookingFunction of Important Components Asymmetric Rectifier Exhaust ThermistorIntake Thermistor Magnetron ThermistorTroubleshooting Guide ServicingRemember to Check 3D Remember to Check 4RTest Procedure Possible Cause Defective Parts Plugged into wall outletTemperature of Intake Thermistor is High Test Procedures Procedure Component Test Letter Magnetron TestMicrowave Output Power IEC-705-1988 Around 20 C Power supply Voltage Rated voltageProcedure Letter Component Test High Voltage Transformer TestCarry OUT 3D Checks Carry OUT 4R ChecksProcedure Component Test Letter Switch TestHigh Voltage Capacitor Test Carry OUT 3D Checks Weak Point A018Fuse F6.3A Test Thermal CUT-OUT Test Carry OUT 3D ChecksTable Thermal Cut-out Test Monitor Resistor Test Carry OUT 3D ChecksProcedure Component Test Letter Magnetron Thermistor Test Exhaust Thermistor TestIntake Thermistor Test Motor Winding TestTouch Control Panel Assembly Test Min Cx ± 20% Cy ± 20% 5mHKEY Unit Test Test Procedures Contd To determine if the control unit or key pad is at faultRelay Test CircuityPower Supply Circuit Power Sync Signal Generating CircuitStop Switch Circuit Exhaust Air Temperature Detecting CircuitDescription of LSI LSIIZA646DR Pin No Signal Description Internal clock oscillation frequency setting inputPower source voltage Signal coming from touch keySound Voltage level control terminal Other Precautions ServicingShapes of Electronic Components 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 CedureComponent Replacement and Adjustment Procedure Outer Case RemovalHigh Voltage Components Removal To remove the components, proceed as followsMagnetron Removal High Voltage Transformer RemovalBlower Motor Removal Stirrer Motor Upper RemovalControl Panel Assembly and Control Unit Removal HOW to Release the Positive Lock ConnectorControl Panel Assembly Removal ProcedurePower Supply Cord Replacement Re-installAfter adjustment, make sure of the following Door Replacement and Adjustment Door ReplacementDoor Adjustment Choke Cover RemovalService Information Preparation for TestingMicrowave Measurement RequirementFigure O-1. Oven SChematic-OFF Condition High Voltage Components Circuit C d eFigure S-3. Printed Wiring Board Parts List Parts marked * are used in voltage more thanElectric Parts Cabinet PartsVCEAB31HW104M Oven Parts Door PartsMiscellaneous SCRE, Nuts and WashersHOW to Order Replacement Parts Model NumberREF. no 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.