Where is the tachometer located in a washing machine?

If “symptoms” of a malfunction in the tachogenerator of an automatic machine are detected, it is necessary to urgently check the element. To diagnose the sensor, you need to understand in which part of the washer to look for it and what it looks like. Let's figure out where the tachometer is located, what the essence of its work is, and what this part represents.

In a machine with a commutator motor

It is not difficult to understand what type of motor is installed in your washing machine. If, when removing the rear wall of the unit body, you see a friction wheel (pulley) on which the drive belt is tensioned, then the machine is equipped with a commutator motor. If, when examining the back of the device, you do not find either a pulley or a drive belt, it means that your automatic machine has an inverter motor. Owners of a washing machine with a commutator motor need to look for a Hall sensor directly on the motor shaft.

The tachometer is located either directly on the shaft or very close to it. Its location will depend on the model of the washing machine, the type of sensor and the design as a whole. Carefully inspect the shaft and areas around it. The connection of wires supplying it is certainly directed to the element. Thanks to the cables connected to the tachogenerator via a chip, you can accurately identify the part you are looking for.

In a machine with an inverter motor

Where is the Hall sensor located in washing machines of this type? It is located inside the electric motor. However, this arrangement will not prevent you from freely approaching the element. The sequence of actions will be as follows:

• remove the rear wall of the unit housing by unscrewing the bolts holding it.On some models of washing machines, the top cover may interfere with this, in which case it will have to be removed;
• inspect the inverter motor cover. It is located on the cross of the rear wall of the drum;
• Loosen the locking center nut and carefully remove the motor cover.

Removing the cover, you will see the tachometer. Once the location of this part has been determined, diagnostic measures can begin.

How to check this part?

To diagnose the tachogenerator, it is not necessary to remove the element from its seat. However, the washing machine motor will have to be removed from the housing. The first step is to disconnect the wiring leading to it, then remove the drive belt and unscrew all the bolts holding the engine. After this, the electric motor is removed from the unit.

To check the Hall sensor you will need a special device - a multimeter. The tachogenerator wires must be disconnected from the connector, and then the resistance on them must be calculated. Switch the tester to resistance measurement mode, attach the probes of the device to the sensor contacts. A working tachogenerator will give a resistance value of about 60 Ohms.

To understand that the tachometer conducts current when the electric motor is running, switch the multimeter to voltage detection mode. Carefully turn the engine by hand, while simultaneously measuring the voltage at the tachogenerator terminals; it should increase. When the motor is running, the voltage should be about 0.2 V.

If diagnostics with a multimeter did not reveal any defects in the operation of the element, check whether the sensor mounting bolt is securely tightened. If the fastening bolt is loosened, the part may “wedge”. If the bolt is not fully tightened, tighten it.

Sometimes it may be due to contacts that have moved away from the element. Carefully check all wiring supplying the Hall sensor to make sure they are connected correctly.

In the event that the tachogenerator does not pass the tester and proves to be inoperable, it will have to be replaced. Hall sensor failure most often occurs due to overload of the washing machine. Therefore, in order to extend the life of the part, strictly control the weight of laundry loaded into the drum.

How to install a new part?

To replace the tachometer sensor of the washing machine, you will have to remove it from its seat. First, disconnect the connectors of the part. They can be freely removed, or they can be slightly secured in a common block. In the second case, you need to carefully pull out the connectors using a thin screwdriver.

Then you should unfasten the tachogenerator cover, which usually simply snaps into place. In some washing machine models, the cover may be secured with several bolts that will have to be unscrewed. After removing the cover, you need to unscrew the bolts securing the Hall sensor itself and remove it.

The new tachogenerator is installed in its original place in the reverse order. It is important to correctly connect the wires supplying the part. In order not to get confused with the connection diagram, before disassembling it is advisable to photograph the initial connection of the contacts and then recreate what is captured in the photograph.

How does the sensor work?

It is important to understand what role the tachogenerator plays in the washing machine system. The sensor is made in the form of a ring with wires on it. When the electric motor operates, voltage appears in the tachometer due to the magnetic field. The nominal value of the voltage generated is directly related to the rotation speed of the motor - the faster the engine rotates, the stronger the voltage generated in the ring.

The tachogenerator allows you to accurately determine the rotation speed of the washing machine motor.

The Hall sensor is designed to control the speed of the motor. The principle of operation of the element is as follows. For example, the engine begins to rotate faster to provide the spin set by the user. So, the engine needs to accelerate to 800 rpm. The control unit immediately sends a signal to the motor to increase speed, but at what point should it stop accelerating? It is the tachogenerator, which measures the number of engine revolutions, when the specified operating parameters occur, that will signal the control unit to stop accelerating the electric motor of the washing machine.

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