Special Maintenance Manual for Induction Cooker - 220V/240V Version Applicable for Electrolux Model ETD28K ETD28KS

Transcription

1 Special Maintenance Manual for Induction Cooker - 220V/240V Version Applicable for Electrolux Model ETD28K ETD28KS Technical Data List of Elements Exploded View Introduction to Induction Cooker Work Introduction to Key Elements of Induction Cooker Cautions in Use of Induction Cooker Removal of Simple Failures Removal of Major Failures

2 ETD28K 345*280*60 ETD28KS 345*280*60 Assemblydrawing:

3 SN. Parts code Parts names Qty Ceramic plate(etd28k) Ceramic plate(etd28ks) Control panel Upper cover Component of display panel Cross recessed pan head tapping screw ST2.9X8 Cross recessed oblate head tapping screw ST3.5X Component of blower Base Rubber feet Cross recessed pan head tapping screw ST3.5X (Philippines) (GS) (BS) Component of power cord Component of control panel Component of coil plate Component of thermistor

4 Principle and structure of induction cooker Design sketch of induction cooker princple Design Generate a great deal of thermal energy Generate vortex at bottom of cooker Induction magnetic field of iron pot Generate high-frequency alternating magnetic field Current passing the coil disc Heating principle diagram of induction cooker By means of the internal control circuit inside the induction cooker, AC electric energy provided by the power cord is converted into electromagnetic energy, which acts on an iron pot on the top of the induction cooker. Thereby, vortex is formed at the bottom of pot, and electromagnetic energy is transformed into thermal energy, realizing the purpose of heating the content in the pot. The induction cooker performs heating by using electromagnetic vortex formed at the bottom of pot, and thus pot material has a great influence on power of induction cooker. Before cooking, be sure to use a pot appropriate for the induction cooker or a pot specified in the instruction.

5 Circuit principle and structure of induction cooker Block diagram of induction cooker AC power supply Bridge rectifier DC electricity LC oscillation loop High-frequency AC electricity IGBT exciting loop High-frequency magnetic field Vortex generated at bottom A great deal of thermal Circuitous philosophy:. AC power supply enters the circuit board through the power cord, reaches the bridge rectifier circuit, after rectification, power frequency electricity converts into 00Hz/20HZ pulsating DC, and after passing through LC filter circuit, forms smoother DC electricity which is applied to the resonant module; 2. Through the control of IGBT exciting loop, DC electricity applied to the resonant module converts into high-frequency AC electricity, and meanwhile, LC resonant module generates high-frequency magnetic field; 3. The action of the high-frequency magnetic field on the bottom of the iron pot produces thermal energy, thus heating the content inside the pot.

6 Topology of Induction Cooker The induction cooker adopts single-ended and parallel resonant topology: coil C AC G drive circuit E current feedback control loop Introduction to key elements of induction cooker IGBT:Isolated Gate Bipolar Transistor External encapsulation of IGBT: Internal structure of IGBT:

7 IGBT model used by 220V/230V induction cooker: Manufactured by Germany Infineon Company: For the specification of IHW20N20R2, IHW25N20R2, see Fig.

8 Fig. IHW20N20R2, IHW25N20R2 Bridge rectifier:

9 Fig. 2 Bridge rectifier The model of bridge rectifier used by 220V/230V induction cooker: RS2006M Fig. 3 RS2006M Cautions in Use of Induction Cooker

10 . Before using the induction cooker, inspect whether there is obstruction within 0CM of the induction cooker. Space of 0CM must be retained for heat radiation from internal temperature rise inside the induction cooker and for steady operation of the induction cooker; 2. Before using the induction cooker, inspect whether the socket voltage is normal. Supply voltage of the induction cooker shall be kept within the range of nominal voltage. Excessively high/low voltage may cause abnormality of the induction cooker in work; 3. Before using the induction cooker, see the Operation Manual to determine whether the pot falls into the use range. Any pot with improper size or material may cause abnormal operation of the induction cooker; 4. If E7,E8 protection codes appear during using the induction cooker, please close the unit immediately. Presence of E7(E8) protection code means that current mains supply voltage is less than the allowable minimum (maximum) working voltage of the induction cooker. To prevent damage to the induction cooker, the MCU inside the unit will protect itself in a compulsory manner. In the event that E7,E8 protection codes appear, it does not mean that the reason is failure of the induction cooker. After mains

11 supply voltage resume, the induction cooker can be used normally; 5. If E,E2,E4,E5,Eb protection codes appear during using the induction cooker, please close the unit immediately. When there are E,E2,E4,E5,Eb protection codes, it indicates that hardness failures have occurred to the internal main temperature sensor, auxiliary temperature sensor and blower, causing the induction cooker impossible to work normally. E/E4 means open-circuit failure occurs to main temperature sensor/auxiliary temperature sensor; E2/E5 means shorting failure occurs to main temperature sensor/auxiliary temperature sensor; Eb means that the main temperature sensor is not installed in place;

12 Removal of Simple Failures Failure No switch-on or no reaction to keying Buzz after switch-on Yes Inspect whether the key is held No Inspect the socket for normal operation Inspect mains supply falling in normal range No Disassemble the unit to inspect whether the key fails? The winding displacement falling? Water entering the lamp board? Lamp board is damaged? Inspect the fuse Normal voltage Burned Inspect whether IGBT, bridge rectifier and piezoresistor are normal Normal Not burned Inspect the crystal Inspect whether MCU power supply Whether there is reaction after replacement with a new crystal Abnormal Replace the main control IC Inspect the power supply circuit such as switch power supply and 7805 Replace the element

13 Failure 2 Automatic shutup (shutup after several minutes or irregular shutup) Heating process of starting Shutup or intermittent heating after running several minutes Blower runs? Air inlet and air outlet are blocked? Yes Fan is damaged? Blower socket is loose? No Yes Pot is correct? Blower is driven? No Power supply or MCU No Replace the Yes Over-temperature on bottom of Replace the mainboard thermal-resistor pot or surface of cooker? No Great change in voltage and too low voltage Removal of Major Failures I. Fan failing to rotate Inspect the power supply of the fan drive is normal; Inspect whether the fan plug is connected normally and reliably; Inspect the fan driving tube for any damage; Inspect the fan motor for normal operation and the fan blade for seizure. II. Fan rotates automatically

14 Inspect whether the crystal is welded correctly and reliably; LED board connector is inserted incorrectly or broken; Whether LED winding displacement is supported on the wire disc (disturbance occurs); Inspect the fan for seizure; Inspect the audion for breakdown. III. Unusual noise of fan Replace with a fan without unusual sound; Whether foreign object enters into fan. IV. Current is not adjustable Inspect whether the current detecting loop on the main baseplate is normal (open circuit, low resistance, poor contact); Inspect MCU for normal operation; Inspect whether the changeable potentiometer for adjustable current on the main baseplate is normal. V. Current cannot be adjusted to low level (high power) Inspect whether the wire disc is too near to the ceramic plate, and just adjust to a proper distance; Inspect the current transformer CT on the baseplate is normal

15 (open circuit, low resistance, poor contact). VI. Current cannot be adjusted to high level (high power) Inspect whether the wire disc is too near to the ceramic plate, and just adjust to a proper distance; Inspect whether the adjustable potentiometer on the baseplate is damaged. VII. Unstable current Inspect whether the pot is flat and the pot material is appropriate. VIII. Buzzer does not sound or sound for long; Inspect the driving loop for normal operation; Inspect MCU for normal operation. IX. Failing to start Inspect the fuse for burnout; Inspect whether the voltage of switch transformer is normal; Inspect MCU for normal operation. X. Failing to heat

16 Inspect whether the pot is correct Inspect whether rosin joint occurs to inductance. XI. Burst (the fuse burnout after switch-on, breakdown of IGBT and bridge rectifier) Measure any damage to key elements such as IGBT, FUSE, bridge rectifier and, driving loop audion; Inspect whether the piezoresistor is burned out; Inspect whether the main loop is shorted.