Do-it-yourself repair of commutator electric motors

What is a commutator motor

A motor of this type is most often a synchronous unit connected to a 220V power source and consisting of:

• stator;
• rotor;
• brush-collector unit;
• bearings.

All parts are enclosed in a housing.

Preliminary check of the commutator motor

If the device does not work, first make sure that the problem lies with the motor itself. For this:

• Check if there is voltage to the device. Plug it into another outlet (the power source may need repairs).
• Inspect the cord for breaks.
• Check if the contact of the power and control buttons is lost, if there is any mechanical damage.

If there are no problems with these parts, disassemble the device. Use the instructions that the manufacturer necessarily includes in the passport.

Possible malfunctions of the commutator motor

Sometimes even people familiar with the structure of the mechanism have little idea how to check a commutator motor. Below we will talk about all possible malfunctions and ways to identify and eliminate them.

• Broken contacts. This is indicated by active sparking.
• Interturn short circuit (short circuit of windings in the collector). It also causes sparking.
• Wear of the brush-collector unit. At the same time, it turns black and sparking appears. Usually the problem is solved by replacing old elements with new ones. To remove the assembly, move the lock and unscrew the mounting bolt (depending on the engine model).
• Darkening of the contact part of the collector. Often it is enough to clean it with fine sandpaper.
• Formation of a groove at the point of contact of the brushes with the commutator. It is necessary to perform the grooving of the unit on the machine.
• Bearing wear. This malfunction can be determined by increased vibration of the housing during engine operation and beating of the cartridge. In this case, bearing replacement is required.
• The armature touches the stator. Sometimes replacing the armature is enough, but in some cases you will have to replace both the armature and the stator.
• Control failure on the microcontroller. Installing a new microcontroller is the optimal solution to the problem.
• Burnout or breakage of windings. Pay attention to their color and integrity. Blackening of the entire winding body or part thereof indicates burnout; a break is easily determined by visual inspection. In this case, they need to be replaced or rewinded.
• Graphite dust in the space between the lamellas. Your appliance just needs cleaning.
• Burnout of wire insulation. A characteristic odor will indicate this problem.

In all of the above cases, restoring the electric motor manifold with your own hands is quite possible if you have the necessary spare parts and tools. Only if you do not have experience in rewinding windings, it is better to contact the appropriate service. After troubleshooting, reconnect all parts in reverse order.

Checking the commutator motor with a multimeter

Let's say a visual inspection did not produce results - at first glance, all components are intact, no breaks were found, and there is no burning smell. In this case, check the device and its elements using a special device - a multimeter. The process consists of several stages:

• Set the device to resistance measurement mode up to 200 Ohms.

• Ring the paired terminals of the stator windings on the lamellas. The resistance values ​​must be the same.
• Check the armature body and lamellas. Ideally, the resistance value tends to infinity.
• Ring the winding terminals. If there is no resistance in one or more circuits, the motor is faulty.
• Check the circuit between the stator housing and the winding terminals. If there is a breakdown in the housing, operation of the unit is impossible.
• Ring the rotor by placing the tester probes on the commutator at the maximum distance from each other. When the multimeter shows a value, turn the rotor slightly until the probes connect to the next winding. Check all windings in this way. If the resistance value in each circuit is the same or differs very slightly, the unit is working.

You should not immediately take a “jammed” device for repair or throw it away, as many people prefer to do. You will save money if you know how to restore the electric motor commutator yourself. The process is not too complicated and does not take much time, and the mechanism can last for a long time.

Damage to the commutator motor power cord

The weak point of a power tool is the power cord. During operation, it is often wound and unwound. At the same time, it most often bends in the same place - at the entrance to the body. Despite the fact that the cord in this place is protected by a rubber insert, over time the flexible wires in it break.

Sometimes a malfunction announces itself in advance: the tool periodically stops and starts working again. It is better not to wait for a complete wire break, but to immediately disassemble the tool, pull part of the cord into it so as to cut out the break point and connect it again.

If the tool stops working, first check the cord for integrity with a multimeter. If it does not ring, then the place of damage is most likely near the housing.

How to use a multimeter, read the article: “How to use a multimeter?”

Checking the power cord

Asynchronous motor malfunctions

There are several causes of malfunctions and their diagnosis for an asynchronous motor, which are combined in the table:

Malfunctions of the electric motor of the Indesit washing machine

Malfunction of the electric motor of the washing machine Zanussi fe 804

How to replace brushes in a washing machine

Before you start replacing the brushes, it's worth watching the video.

Even a reliable and durable Ardo washing machine requires regular inspection and replacement of worn parts. After 5 years of operation, it may be necessary to replace the motor brushes, which may lose full contact.

If a malfunction is detected in the electric motor of an Ardo 1000 washing machine associated with replacing the motor brushes, you must purchase the following set of tools and accessories:

• New brushes.
• Multimeter.
• Screwdrivers.
• An ordinary vacuum cleaner.

Instructions for replacing motor brushes:

• The washing machine is de-energized;
• This frees up space near the rear wall of the unit for ease of work;
• The back wall is removed after unscrewing the screws holding it;

To determine the placement of the electric motor in a washing machine, you need to locate the drum pulley, and then the motor and the drive belt that connects them. The belt is removed after prying it off with a screwdriver and turning the pulley.

• Before removing the engine from the car, disconnect the power connector from it and unscrew the screws;
• The motor is removed;
• The engine is wiped or vacuumed, which may become covered with graphite dust, interfering with further procedures;
• The engine is tested for leaks and short circuits to the frame. The most convenient way to do this is with a multimeter;
• Remove power from the contacts of the brush holders by pressing on them;
• The contacts are pulled out of the motor housing;
• Brush wear is determined by the size of the graphic area: if its size is less than 5 mm, replacement must be done;
• The new brush is ground into the commutator by placing sandpaper on it and turning it a few turns;
• The same procedure is repeated with the second brush;
• The engine is vacuumed again;
• The motor is completely assembled and installed in the Ardo washing machine;

At this stage, a drive belt is not needed. The machine simply starts in washing mode. This must be done so that the brushes rub well into the engine commutator.

• The drive belt is put on the engine pulley, and then on the drum pulley;
• The washing machine is completely assembled;
• The back wall is installed and secured.

In the same way, faults in the electric motors of tl washing machines are eliminated.

Break and short circuit of stator and rotor windings

When the engine power decreases, a short circuit may have occurred between the turns of the winding. In this case, the machine drum may stop rotating or rotate slowly.

When the engine stopped, most likely there was a break in the stator windings. This can happen when the motor housing heats up too much, which is caused by a short circuit in the motor windings. When the engine heats up to a temperature above 90ºС, a special protective thermostat is activated.

Tip: The optimal temperature for operating the electric motor should not exceed 80ºC.

To check for an open circuit in the windings, you can use a tester in ohmmeter mode connected to adjacent lamellas. In different positions of the shaft between the lamellas, the resistance of adjacent elements should be the same - from 0.1 to 0.4 Ohm.

A short circuit in the motor winding may occur if the insulation is damaged. In this case, you will need to change the entire motor, or create the winding again, but this is very difficult. A short circuit in the engine can also cause other problems.

Types of engines

Before troubleshooting a washing machine motor, you need to determine the type of unit.

For this purpose, three modern types of engines are produced, their features are presented in the table:

Collector faults

During intensive use, the brushes develop an annular depression underneath them on the commutator. It negatively affects their work. For powerful engines, you have to remove the armature, install it in a lathe and grind the manifold, aligning it. But for household electrical appliances, such an operation is not economically justified - it is easier to buy new equipment. In addition, the wear of the collector will affect itself in a few years, when the electrical appliance becomes obsolete, and the new device will be more functional.

Collector with worn lamellas

In domestic conditions, the collector can only be cleaned. To do this, use very fine sandpaper. She wraps herself around the collector and presses it tightly with her hand. Cleaning is done by rotating the collector in different directions, periodically changing position.