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

Assemblydrawing:

ETD28K

ETD28KS 345*280*60

345*280*60

SN. Parts code Parts names Qty

Component of display panel

1

1

1

1

1 Upper cover 1

2

303207100505

1 532400100063

532400100065

Ceramic plate(ETD28K)

Ceramic plate(ETD28KS)

3

303203101311 4

Cross recessed pan headtapping screw ST2.9X8 6 5 301500101195

9

1

1

1

1

1

1

1

1

7

8

303203400018 Component of blower

10

303207200304 Base

11

7 301500101204

13

14

15

2 303207500007 Rubber feet

Cross recessed pan headtapping screw ST3.5X10

303203601131(Philippines)

532200000038

Component of power cord

303208101059 Component of thermistor

532400000033 Control panel

6 6 301500101190Cross recessed oblatehead tapping screwST3.5X14

Component of controlpanel

Component of coil plate303203501112

303203601091(GS)

303203601155(BS)

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.

PrinciplePrinciplePrinciplePrinciple and structure of induction cooker and structure of induction cooker and structure of induction cooker and structure of induction cooker

Current passing the coil disc ▲

Generate high-frequency

alternating magnetic field ▲

Induction magnetic field of iron pot

Generate vortex at

bottom of cooker

▲

▲

Generate a great deal

of thermal energy

cooker princple DesignDesign sketch of induction

Circuitous philosophy: 1. AC power supply enters the circuit board through the power cord,

reaches the bridge rectifier circuit , after rectification, into 100Hz/120HZ

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.

Circuit principle and structure of induction cooker

AC power supply Bridge rectifier

IGBT exciting loop

High-frequency AC electricity

LC oscillation loop

High-frequency magnetic field

Vortex generated at bottomA great deal of

thermal

DC electricity

Block diagram of induction cooker

power frequency electricity convertspulsating DC, and after passing through

Topology of Induction Cooker The induction cooker adopts single-ended and parallel resonant topology:

G

CE

current feedback control loop

drive circuitAC

coil

Introduction to key elements of induction cooker

IGBT：Isolated Gate Bipolar Transistor

External encapsulation of IGBT:

Internal structure of IGBT:

IGBT model used by 220V/230V induction cooker:

Manufactured by Germany Infineon Company:

For the specification of IHW20N120R2, IHW25N120R2, see

Fig.1

Fig. 1 IHW20N120R2, IHW25N120R2

Bridge rectifier:

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

1. Before using the induction cooker, inspect whether there is

obstruction within 10CM of the induction cooker. Space of 10CM

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

supply voltage resume, the induction cooker can be used

normally;

5. If E1,E2,E4,E5,Eb protection codes appear during using the

induction cooker, please close the unit immediately. When there

are E1,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.

E1/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;

Removal of Simple Failures

Failure 1 No switch-on or no reaction to keying

Yes

No No

Normal voltage Burned

Not burned Normal

Whether there is reaction after

replacement with a new crystal

Abnormal

Buzz after switch-on Inspect whether the key is held

Inspect the socket for normal operation Disassemble the unit to inspect

whether the key fails?

The winding displacement

falling?

Water entering the lamp board?

Lamp board is damaged?

Inspect mains supply falling in

normal range

Inspect the fuse

Inspect whether IGBT, bridge

rectifier and piezoresistor are

normal

Inspect whether MCU power supply Inspect the crystal

Replace the main

control IC Inspect the power supply circuit such

as switch power supply and 7805

Replace the element

Failure 2 Automatic shutup (shutup after several minutes or irregular shutup)

Shutup or intermittent heating after

running several minutes Yes No Yes No No Yes No

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

Heating process of starting

Blower runs?

Air inlet and air outlet are blocked?

Fan is damaged? Blower socket is

loose?

Blower is driven? Power supply or MCU Pot is correct?

Over-temperature on bottom of

pot or surface of cooker?

Replace the

thermal-resistor

Great change in voltage and too low

voltage

Replace the mainboard

� 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

(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

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.