Many people do not think about the complexity of the mechanisms inside the washing machine. But it happens that the machine breaks down, and often the cause of the breakdown can be such an inconspicuous part as a tachometer or tachogenerator of a washing machine.
What is a tachometer and how it works
This device looks like a small iron ring with a pair of wires. It is located on the electric motor shaft. When the latter rotates, the tachogenerator is subject to voltage, which is influenced by the electromagnetic field. Then, in accordance with the increase in the number of revolutions, the voltage also increases.
This creates the resistance needed to measure the speed of the rotating motor shaft through voltage force. Then all data is sent to management module.
How to understand that the tachometer is broken
It is quite easy to detect a malfunction of a washing machine, since most of its functions are impaired. But a tachogenerator breakdown can be distinguished from others using a number of the following signs:
- Sudden sharp changes in the speed of the rotating shaft;
- Too high rotation speed when washing, which is several times higher than usual;
- Very low drum speed during spinning or lack thereof (the drum does not rotate);
- After the washing machine has finished working, the items remain poorly wrung out or completely wet.
How to check for damage
Do not rush to change the tachogenerator thinking that its failure is irreparable. Very often, the tachometer in a washing machine does not function correctly due to minor malfunctions in its operation. The causes of such malfunctions are described below:
- The problem may first be visible on the control module. You need to pay attention to the button that turns on the spin mode. If it is clamped, then the malfunction occurred precisely for this reason.
- To check the next reason, you need to get to the tachogenerator itself. The entire breakdown may consist of its poor fastening on the rotation shaft, because vibrations of the machine during washing can loosen the fastenings and move the tachometer from its place.
- Abnormal contact resistance can also cause a malfunction. To check if this is the case, you need to take a multimeter and put it in resistance measurement mode, the unit of measurement of which is Ohm. Next, you need to attach the tester to the contacts that are in an inactive state. The resistance should fluctuate around 60-70 ohms.
- You can verify the correct operation of the tachogenerator by measuring the current when the drum rotates. To do this, you will need the same multimeter, but switched to measuring voltage in Volts. By rotating the drum you need to measure the voltage on the tachogenerator. At higher rotation speeds, the voltage should increase. During rotation, it usually does not exceed 0.2 Volts.
- Lack of grounding can also cause a breakdown. If a charge gets on the motor pulley, the operation of the motor is seriously disrupted.As a result, the entire mechanism of the washing machine suffers.
Where is the tachogenerator located?
As already mentioned, this device is quite easy to find. The tachometer is located on washing machine motor, or rather, on its rotating shaft. To get to it, you will need to disassemble the washing machine, but not completely, but only the back part. To do this, you will need to remove the panel, which is usually located at the back, using a screwdriver.
Next you need to find an electric motor. It is located next to the rotation wheel and is connected to the latter using a drive belt. Then on the rotation shaft you can see a small iron ring - the tachogenerator of the washing machine. But if you need to replace the tachometer, you will also need to remove the engine. Well, without the appropriate qualifications, it will be quite difficult to figure it out on your own.
If you are not very familiar with the operation of this type of electrical appliance, it is not recommended to repair the tachogenerator or other parts of the washing machine.
Not only can the problem only be aggravated without a certain knowledge of electronics, but also if the parts of the washing machine are handled incorrectly, after such a “repair” a complete replacement of the unit may be required. Therefore, it is best in this situation to turn to the help of qualified craftsmen.
