The motor brushes of power tools spark: the reason is that they spark strongly at the armature of a drill or grinder

Posted on March 31, 2017 by Johhny

During operation, devices with a commutator motor may spark. Strong sparking often indicates imminent tool failure. It is necessary to promptly understand the reasons for the occurrence of increased sparking and take measures to eliminate it. The article discusses the most likely reasons for the occurrence of this negative phenomenon.

The basis of devices with AC electric motors is a brush-commutator module, which ensures electrical contact of the rotor with the static part of the electrical device. This module consists of two parts: a commutator located on the rotor and brushes - sliding contacts located outside the rotor part and pressed against the commutator. Sparking on a commutator motor occurs as a result of the mechanical interaction of moving and stationary parts. The contact between the commutator and the brushes is periodically interrupted, which leads to a transient process in the electrical circuit and entails the appearance of a spark. The motor commutator brushes are the most short-lived part of the design. Therefore, over time, various problems associated with their operation may occur.

Even on a serviceable electric motor, there is usually weak sparking from the brushes. If the electrical appliance turns on normally, develops speed at full power, and sparking is hardly noticeable, then there is no reason to worry.

Causes of electric motor brushes sparking

Let's look at the most common faults of the brush-commutator unit.

1) Wear of brushes. If these elements are severely worn, the electric motor does not develop speed at full power, and may also not turn on (continuously or periodically). In this case, when the electrical appliance is turned on, you can press the brush against the armature with a screwdriver with an insulated handle. If an increase in engine speed is observed, then the problem has been correctly identified. Most likely, replacing worn parts with new ones will correct the situation. Sometimes the brush holder springs also need to be replaced.

2) Interturn closure of the armature winding. A malfunction of devices with electric motors may be a broken armature. In this case, sparking will be observed in the area of both brushes, in addition, the armature winding will become very hot due to the fact that some contacts receive a larger current than others. When repairing this malfunction, the armature winding is rewound or the part is completely replaced.

3) Stator failure. When a stator breaks, usually only one of the brushes sparks. To check it, you need to measure the resistance of the windings. The same resistance of both windings (usually 4 ohms) indicates a working stator. Different resistance on the windings indicates that the stator is faulty and its winding needs to be rewound.

4) Closing the collector contacts. As a result of contact wear, graphite dust is formed, which accumulates between them, shorting them. In this case, large sparks are observed during operation of the electrical appliance. To eliminate the breakdown, it is necessary to clean the spaces between the contacts from graphite dust. It is also necessary to check the commutator brushes, since if they are correctly positioned and in the correct shape, dust appears in minimal quantities.

5) Contamination of the collector contacts. If the contacts are contaminated with carbon deposits, both brushes will spark, and the electric motor will not be able to reach full speed. Carbon deposits appear on the manifold when it overheats. Poor electrical contact will lead to an increase in resistance in the element, which in turn will lead to even more sparking and carbon deposits. In this case, it is necessary to clean the collector contacts from carbon deposits. This is done with sandpaper of minimal grit. It is important when cleaning not to damage the shape of the contacts. Therefore, special pads must be used for cleaning. At home, you can use a screwdriver for cleaning. The armature is clamped into the cartridge, rotating at minimum speed, and carefully placing the sandpaper against the commutator. The direction of rotation of the armature during cleaning must coincide with the direction of its rotation in the electrical appliance.

So, your drill sparks on the brushes and you don’t know what to do in this situation. This article will tell you why this happens, whether it needs to be fixed, and if so, how.

It is immediately worth noting that the presence of the specified sparking during operation is a completely acceptable phenomenon. This is true only if the sparks are small and there are not so many of them. If they just fall out, this may indicate a malfunction.

Note that on a new, working power tool, the brushes may also spark strongly at first, since they need to first get used to. Grinding in usually takes 10-15 minutes of work. If after this everything remains as it was, then it is better to take the instrument back to the store with a claim.

If your drill is no longer under warranty, you can try to fix it yourself.

But first we will describe the reasons for this phenomenon.

Control Panel

Automatic washing machines produced by other brands are equipped with an electronic control module.
He adjusts the washing parameters and is responsible for ensuring that the machine operates with minimal human intervention. Sparks when the control unit breaks down occur extremely rarely. The malfunction at the initial stage is manifested by failures in washing programs and blinking indicators. Then the control panel will stop responding to button presses, the machine will not turn on or refuse to perform its functions.

Repairs are possible, but are rarely done. More often, a complete replacement of the control unit is required to ensure flawless operation of the equipment.

How to use a reciprocating saw?

The reciprocating saw is not widely used among domestic consumers. In structure and principle of operation, it is most similar to a hacksaw. Only instead of human power, an electric motor works. This tool is easy to use because the ergonomic handle fits well in your hand.

Ideal for garden work where several branches need to be cut down. Thanks to the thin working surface, the saw will not cut off excess. The advantage of a reciprocating saw is that it can cut not only wood, but also stone, ceramic materials, gas block, glass, plastic, etc.

Reciprocating saw Stavr PS-850

Why do brushes spark in an electric motor, what does this phenomenon lead to and how can it be eliminated.

Topic: what to do if the brushes in an electric motor spark strongly.

So, from the beginning I will say that the sparking itself during the operation of collector electric machines is normal, only it should be very small, barely noticeable to the eye. It’s not normal when the electric motor is running and sparks fly out from its brushes - that’s bad. The very phenomenon of spark formation is associated with intermittent electrical contact that occurs during the rotation of the armature, at the moment of mechanical transition of the brush from one contact, on the commutator, to another. At this time, the circuit breaks and the current flowing through the armature coils ends its passage with a spark, a small arc discharge. Therefore, the greater the power and current in the circuit, the more noticeable the spark will be. But besides this, there are other factors that contribute to an increase in spark.

You should also pay attention to the condition of the gaps between the contacts on the collector. It often happens that they are clogged with graphite dust, which is a conductor with a certain resistance

Naturally, if these gaps are dirty, then you also put them in order (clean them with a sharp tool). Don’t forget to check the condition of the brushes, their performance, clamping force, and freedom of vertical movement. If problems are identified with the brushes, be sure to fix them. Please note that when replacing graphite brushes, you should take into account that they are different. In this case, try to find exactly the same type as the old ones.

The armature should be checked in an alternating electromagnetic field. If there are short-circuited turns, then in such a field the armature will begin to rattle, since induced currents will begin to form in it. To do this, you can make a homemade device from a power transformer, first making a wedge-shaped cutout on its core, into which you need to insert an armature for testing.

Since this is important, I repeat once again - increased spark formation during operation of the electric motor affects its service life. In this case, strong carbon deposits quickly appear on the contacts of the collector, which after a while will damage the electrical equipment.

It is better to eliminate the sparks immediately than to replace the entire armature later.

Iskrit Shuropovet AEG

Box wrote: When you smoothly release the start button (at second speed), when the number of revolutions decreases, you can clearly hear that even when the speed is not equal to O, either a mechanical brake or a spindle lock is trying to turn on.

Not equal to zero, but close? Agree that it would be ridiculous: a weakened motor controlled by a pushing PWM controller (reduced speed is difficult for everyone) tries to continue turning, and then a hard spindle stopper comes in and everything jams. This will not just be a release of sparks, but a real short circuit. This should not happen. The brake (either electric or mechanical) should not be turned on at the same time as the engine. Just keep it apart. This is exactly what I have on my Bosch:

Pressing the button completely triggers the 2nd additional contact pair, which bypasses the PWM controller in the button. In this case, the motor operates from 12 V “directly”. => Maximum speed and power.
When the button is smoothly released, a click is heard (not just during operation, but with the battery removed), this switches off the shunt contact and PWM starts working (at the maximum value of the rotation speed, that is, approximately 80% of the maximum (“directly”). As the button is released, the frequency drops (almost to zero) without any extraneous sounds. If you try very hard, you can stop the motor and listen to the PWM whistle (it is very quiet, sometimes it is mistaken for the whistle of the bushings, but the mechanism is motionless, so this is incorrect By the way, not everyone can hear, these are high-frequency sounds.)
If the screwdriver turns at high speed and the button is released abruptly, two conditions coincide: rotational inertia and the first additional pair (electric brake) is closed, a large spark occurs and the motor stops quite abruptly. In this case:
If the screwdriver is at 2nd speed, a sharp click is heard, as if the brake pads are being activated. But it's just a gearbox. The motor is abruptly stopped by an electric brake, and the spindle with the equipment still tries to spin. This is where the shock impulse occurs. If the spindle stopper had braked, this would not have happened, since it brakes in the same direction as the resistance of the fastener-equipment-material. And then it turns out that reverse is switched on for a short time on the engine. The equipment flies forward, and the motor stops it with a jerk. The backlash in the gearbox is selected. With a click. At speed 1 this is unnoticeable, apparently due to the lower inertia of the spindle and equipment. By the way, my loosely tightened cartridge unwinds from these jerks

Reasons why brushes spark

Very often you can notice how the brushes on an angle grinder sparkle. Signs of sparking are detected through the ventilation holes in the body of the power tool. Craftsmen are interested in why the brushes on an angle grinder spark, even after they have been directly replaced. There are many reasons for this, and to understand this, you need to have an understanding of the structure of a power tool. If you know how the angle grinder works inside, then understanding why the brushes spark strongly will not be difficult.

https://youtube.com/watch?v=W-k9JyxuWik%3F

The reasons for strong sparking of brushes on grinders are the following factors:

Faulty armature winding. If a violation of the insulation of the armature winding occurs, then this ultimately contributes to the development of an interturn short circuit, as well as a short circuit to the core. In addition, a winding break may occur, which will ultimately cause an increase in load. A characteristic sign of a faulty armature winding is a decrease in speed, an increase in noise and a drop in power
The brushes do not press well to the commutator. A spring is responsible for pressing the main part, which, over time, loses its original springing properties.
The rotor winding has broken off from the copper plate of the commutator - this phenomenon is extremely rare, however, if the power tool is overloaded, it may well occur
The centering of the electric motor armature is disrupted, which ultimately contributes to strong sparking of the brush on the angle grinder
The shape of the collector is broken. The collector, consisting of copper lamellas, has a cylindrical shape, which can be broken when the rotor is rewinding. At the slightest deformation of the commutator shape, sparking of the brushes will occur
Violation of insulation between the collector lamellas. Each collector plate is insulated from each other, and if the micanite insulating layer is damaged, sparking occurs. The insulation between the plates may also be compromised due to the settling of the graphite layer in the grooves
When the armature bearings are worn. If the bearings are faulty, then a beating of the rotating armature occurs, and as a result, signs of sparking appear
Curvature of the rotor shaft. It is difficult to bend it, but if this happens, the engine begins to work under load. To prevent the tool from malfunctioning, it is recommended to replace the rotor
If the ends of the armature windings are soldered incorrectly to the copper plates of the collector. Such errors are not allowed at the factory, but they can be made by the wrapper who rewinds the armature of the power tool.
Inappropriate composition of graphite brushes. The parts in question are made from coal and graphite, adding different types of impurities. This is done for a reason, but in order to use brushes depending on the voltage and shaft rotation speed. Graphite can be soft or hard. The lower the supply voltage, the softer the grade of graphite selected. For high-voltage power tools, it is necessary to take hard brushes that do not contain copper.
Deformation of the lamellas due to their heating. If the angle grinder experiences excessive loads, deformation of one or more lamellas of the collector may occur. The plates rise relative to the others, resulting in the contact being broken. This malfunction causes strong sparking of the brushes when operating the power tool.
Poor contact at the brush connection point. If the terminal is loosely connected to the device, the result of this contact failure may manifest itself in the form of excessive sparking
Presence of carbon deposits on copper plates - periodically or regularly it is recommended to clean the surface of copper lamellas from carbon deposits. Carbon deposits usually appear due to wear of the brushes, so if blackening is detected on the surface of the commutator, it should be wiped with alcohol

Often, after changing the brushes on an angle grinder, craftsmen observe the phenomenon of excessive sparking. Based on the factors described above, you can identify the cause and eliminate it before the tool fails. The elements in question are inexpensive, but due to their incorrect selection and use, the power tool may break. To find out what malfunction is causing strong sparking, you will need to disassemble the power tool and inspect it, as well as ring the rotor winding.

https://youtube.com/watch?v=JhnK8Mi2syY%3F

Advice from professionals

Some professional tips will help prevent breakage of the angle grinder's armature and extend the life of the power tool. Preventing dust and dirt from entering the housing:

use a construction vacuum cleaner to remove dust when sawing non-metallic materials;
pour water over the cut area, reducing dust emissions;
cover the air intake grilles with gauze or a piece of nylon tights, periodically change/clean this insulation;
adjust the gearbox so that the direction of rotation of the wheel is turned away from you - dust and other sawing products will be directed away from the air intake grilles;
Do not place the angle grinder on the ground, in sand, mud or on wet surfaces.

Tips for working with an angle grinder:

immerse the cutting disc into the material slowly, without pressure;
help sawing by moving the grinder back and forth;
compare the volume of sawing and the properties of the material with the technical characteristics and power of the grinder;
If it is possible to adjust the speed, do not saw at low speeds for too long.

To learn how to check the angle grinder's anchor, see the following video.

Electric motor brushes - causes of sparking, methods of checking and eliminating

A distinctive feature of all electric motors is the presence of a commutator-brush assembly in their design. It provides an electrical connection between the rotor circuit and the circuits in the stationary part of the motor, and consists of a commutator (a series of contacts on the rotor itself) and a brush (moving contacts outside the rotor, pressed against the commutator).

When an electric motor is started and running, it almost always sparks. Sometimes this does not mean anything terrible, but sometimes it signals that the device will soon fail. In any case, it is useful to know why the electric motor sparks in the first place - this will help, if necessary, take timely measures. In this article, we will look at the reasons for the occurrence of sparks during operation of the electric motor and ways to combat problems that cause increased sparking.

First, let's define it - inconsistent contact between the brushes and the commutator leads to sparking by default. This is due to the fact that during operation the electrical circuit of the rotor closes and opens many times per second.

The rotor contains a winding. This winding is a load of mainly inductive nature. This, in turn, means that by breaking such a circuit, we start a transient process associated with the appearance of small arcs from the self-induction of the winding - both the rotor itself and the stator. It is clear that brushes and commutator plates wear out over time, but sometimes problems arise not only because of it.

Taking into account the above facts, it must be admitted that even a serviceable and well-fitted electric motor cannot operate without sparking at all. A working device in normal mode develops operating speed, gains power and sparks a little. But if there are a lot of sparks, this is a serious cause for concern.

Brush wear as a cause of sparking

The first and main reason for sparking is wear of the brushes. If there is significant wear, the engine will not be able to develop full speed and gain full power; in addition, it will spark very strongly and will not start immediately.

How can I determine if this is the reason? If you press the worn brushes against the commutator with a screwdriver or other tool, this will seal the contact and start the engine, but after the pressure is loosened, strong sparking will appear again - the space between the brushes and plates will be filled with small arcs. With such symptoms, we can conclude that the brushes are worn out and require replacement. Sometimes it is possible to replace the brushes separately, but more often it is necessary to replace the entire set, including the brush holder and springs.

Short circuit in the rotor winding as a cause of sparking

The rotor winding in a commutator motor consists of several sections. If one of them is damaged and an interturn short circuit occurs in it, then the current will flow into it with greater force than into the others. Because of this, part of the winding will begin to overheat and begin to generate an increased number of sparks. This is exactly how this reason can be established - sparking will increase only in a separate area, and not evenly. This can be corrected by rewinding the rotor or replacing it.

Malfunction of the stator winding as a cause of sparking

The malfunction is very similar to the previous one and is diagnosed in the same way - uneven sparking. If everything is in order with the rotor winding, then check the resistance of the stator winding - it should be the same for each half. A significant difference in resistance indicates the need to rewind or replace the stator.

Collector contamination as a cause of sparking

As the engine operates, its brushes wear out and graphite dust forms on the commutator. It accumulates between its plates and creates additional unwanted short circuits, which, in turn, spark. In this case, it will be enough to remove dust and dirt between the plates using sandpaper.

It would also be a good idea to check the position of the brushes - any deviation from the normal position greatly accelerates the formation of dust and wear of the brushes.

Another reason for contamination of the collector is carbon deposits on it due to overheating during operation. When all other causes of sparking on engines have been checked and eliminated, clean the commutator contacts from carbon deposits - this will improve the contact of the brushes with it and reduce the number of sparks generated. Carbon deposits are removed in the same way as graphite dust - with sandpaper. The only difference is that the rotor must be rotated while the commutator is clamped.

Read further:

Why do brushes spark in a power saw?

Why do brushes on a drill burn?

Why do the brushes on a vacuum cleaner burn?

How to check generator brushes with a multimeter

Why do sockets spark when plugged in?

Typical breakdowns in electric saws and methods for their repair

31.05.2017

Electric saws are preferred for one good reason - they are very light and therefore easy to use. Of course, you won’t go far into the forest with it - the network cable won’t let you in. But when used near the house (for sawing logs, harvesting firewood, pruning trees, during construction and repairs), you cannot find a better tool.

During operation, especially with frequent use, the electric saw begins to act up: it makes strange sounds, smells, does not brake on time or does not turn on at all. There is nothing you can do - any technical device does not last forever. And every working day shortens his life. But there are breakdowns that only professional service can handle (for example, the case is damaged). And there are cases when you can revive an electric saw with your own hands, with effort, knowledge and skill.

We have compiled a selection of practical tips on how to repair a saw yourself, without contacting a specialist.

What causes electric saws to fail most often?

Any breakdown does not occur out of nowhere. Its roots often lie in poor assembly and quality, or in improper operation. If you buy a quality tool from a reliable one, it is not so easy. But still, most often malfunctions arise due to:

Power surges in the network. If the instrument has built-in fuses - protection against voltage surges, then it will withstand deviations from 220 V by 10% in one direction or the other. Not more. If there is no protection, the motor burns out.

Non-compliance with recommendations. Often the instructions indicate: half an hour of work, 15 minutes of break. Once it is written, it must be observed. Avoiding the mode means overheating the engine.

Untimely lubrication. The vast majority of electric saws have automatic lubrication. Make sure you don't run out of oil. Remember that running “dry” is death for the engine. If oil does not automatically flow to the sprocket, then lubricate it yourself every 3-5 hours of operation.

Power overload. If it happens, it’s also your fault, not the manufacturer’s. If it is stated that you can cut logs up to 5 cm in diameter, then cutting a ten-centimeter trunk is clearly overkill.

Design flaws. This is already an oversight by the manufacturer. The most common disadvantage is the rigid coupling of the gearbox with the anchor. When transferring a strong load (dull tape or hard wood), it jams and heats up. Gears wear out quickly. The way out of the situation is to sharpen it in time and avoid overload.

The drill sparks on the brushes - what to do

So, your drill sparks on the brushes and you don’t know what to do in this situation. This article will tell you why this happens, whether it needs to be fixed, and if so, how.

If your drill is no longer under warranty, you can try to fix it yourself.

But first we will describe the reasons for this phenomenon.

Why do brushes spark in an electric motor?

Sparks, including on a working engine, appear due to mechanical action between the brushes and the commutator. The brush, moving along the commutator from one of its contacts to another, alternately forms and breaks a connection with each of them. Now remember what happens if you unplug any working electrical appliance from the socket - usually at such a moment a spark jumps between the plug and the socket. In the case of a brushed motor, this is the same phenomenon.

Therefore, a small spark even on a working electric motor is acceptable, since connections and ruptures constantly occur here.

Causes of severe sparking and how to eliminate them

Now let's move on to strong sparking. It occurs mainly for the following reasons:

contamination of collector contacts with carbon deposits
graphite dust getting between the collector contacts
interturn short circuit in the armature winding

Let's go through each point separately.

1) Soot contamination occurs as a result of engine overheating. The presence of carbon deposits leads to even more friction, which leads to even faster overheating and even more carbon deposits. Which very quickly leads to breakdown.

Excessive sparking here results from the fact that carbon deposits form additional resistance, which causes the spark to break when it breaks, becoming larger and more powerful.

In general, carbon deposits should be removed immediately.

This is done with zero grade sandpaper. That is, you need to remove the collector along with the armature and carefully clean it. Ideally, it is advisable to carry out the grinding on a lathe so as not to disturb the correctness of the circle. But, as a rule, this is not possible, so you can get by with manual stripping. The main thing is not to overdo it.

2) When using a drill, the brushes wear out, which causes the formation of graphite dust. It can easily accumulate between the collector contacts and lead to short circuits between them, since it is a conductor of electricity and has its own resistance. Because of this, the current is distributed unevenly, which leads to large sparks in some places.

In a working drill, wear occurs quite slowly, so graphite dust hardly accumulates. Accordingly, its accumulation signals that the brushes are in the wrong position during operation. This usually happens when they do not stand tightly in their groove, but, on the contrary, have some play.

This often happens when replacing brushes, when they are selected to be not quite suitable in size.

Therefore, when replacing this point, you should pay close attention.

Repair of such a malfunction is carried out by removing dust with some pointed tool and replacing the brushes with more suitable ones.

3) In the event of an interturn short circuit in the armature, the current flows in a larger value to some contacts and a smaller value to others. Because of this, more current flows in some places than necessary, resulting in large sparks.

Identifying such a short circuit should be done when the two previous points did not give much effect. It is produced using a special device that creates an alternating magnetic field. When an armature is placed in this field, it begins to rattle, as induced currents appear in it.

Some people make such a device themselves from a power transformer, in the core of which a cutout is made where the armature is placed.

If the reason turns out to be an interturn short circuit, then you need to rewind the winding or completely replace the armature.

These are the causes of excessive sparking on the drill brushes. Remember, if you don't do anything about it, the engine will most likely break down soon. Therefore, do not be lazy and follow the recommendations indicated in the article.

Why doesn't the AL KO electric saw work?

Reasons why the ALCO electric chain saw does not start or does not work correctly

The German ALCO electric chain saw is a lightweight and easy-to-use power saw that can easily handle thick branches, boards and other types of wood.

This technique is reliable and trouble-free, but due to wear of the equipment and carbon brushes, problems with starting and operating the tool are possible.

What to do if the reason why the AL KO electric saw does not turn on and, moreover, does not make a neat and even cut is due to problems in the assembly or faulty equipment of this sawing power tool?

articles:

Problems during operation of the AL-KO electric saw

You can quickly understand why the ALCO electric saw does not cut or why its powerful cordless analogue, the ALCO chainsaw, does not work correctly if you study the design of this sawing tool.

In most cases, the timely activated automatic chain brake helps the operator and the tool to avoid problems:

A kickback, the essence of which is to throw the ALCO electric saw towards the operator. This situation may arise if the edge of the electric saw bar rests on the workpiece being processed. An automatic electric chain brake protects the operator from injury due to kickback.
This important structural element is also called inertial, since the protective shield located near the operator’s left hand changes its position due to the inertia of the reverse impact, while the chain stops, and the working person’s hand is protected by the shield. The inertia brake system not only protects the person, but also reduces the need to repair the saw, since the power tool will not be damaged in the event of an impact.

Automatic lubrication of the saw chain also extends the life of the electric saw.

The weak points of electric chain saws are:

The design of gearboxes, consisting of a rigid connection with the armatures of electric motors. The entire load falls on the electric motor. In the case of a hard workpiece or a dull saw chain, the latter does not slide smoothly over the workpiece as required, but causes overheating of the engine or premature wear of other components. Timely re-sharpening of the electrical chain, and if the operator does not put too much pressure on the electric saw, will help maintain the functionality of the tool.
Dependence on unstable voltage in the electrical network. When the voltage drops, the load on the electric motor increases. And, if the model does not have built-in thermal protection, the engine may burn out.

How to fix and what to do if the vacuum cleaner motor brushes spark

If the household unit begins to work worse, and standard cleaning of blockages does not bring results, it is necessary, first of all, to disassemble the engine. What to do if the vacuum cleaner motor sparks depends on the type of problem.

How to replace worn brushes

Most often, the vacuum cleaner engine sparks in the area of the brushes precisely because of the natural wear of the latter. Although modern models have special capacitors that slow down abrasion, sooner or later contact between the elements leads to unpleasant problems.

Worn parts need to be replaced. To remove them, you need to remove the back cover of the vacuum cleaner, find the brush holders and pull the latches with your hands or a screwdriver. Then all that remains is to purchase exactly the same elements.

Old brushes can wear down to the springs

In order not to make a mistake with your choice, you can go to the store with the old removed parts and, with the help of a consultant, buy similar ones. Then they are installed in the old place, secured with latches and the vacuum cleaner is assembled in the reverse order.

How to eliminate poor contact of new brushes

If the vacuum cleaner is completely new, or the brushes have recently been replaced, and the motor still sparks, the reason may be a poor fit to the commutator. The problem can be solved quite simply. The engine compartment is opened, the engine is removed and the protective casing is removed from it.

It is necessary to polish the vacuum cleaner brushes with the finest abrasive.

It is necessary to go over the installed brushes with sandpaper to eliminate the smallest roughness. You can also use abrasive sandpaper to treat the collector plates if they have scratches. The smoother the contacting surfaces are, the less likely it is that the vacuum cleaner will start sparking.

How to change the angle of the brushes

If the brushes are skewed relative to the commutator after prolonged use of the vacuum cleaner, sparks will occur when the engine operates. To resolve the problem you must:

remove the motor from the vacuum cleaner;
visually determine how correctly the brushes are positioned relative to the commutator axis;
Use a screwdriver to tighten the two screws securing the brush holder to align the elements.

In old vacuum cleaners, you need to carefully examine the condition of the connecting nodes between the collector and brushes. If traces of corrosion and even cracks are visible on them, such elements must be replaced with new ones.

When the axis is knocked down, the brushes begin to contact the commutator loosely

How to clean dirt

Coal dust and the resulting carbon impair the friction between the brushes and commutator and cause the engine to spark. The problem can be resolved by regular cleaning. The motor is removed from the unit and the casing is removed, after which the brushes are disconnected and access to the commutator is opened. If dirt is noticeable on the surface of the parts, they are treated with fine sandpaper until completely clean.

Plaque accumulates on the brushes and commutator, so when cleaning they are additionally degreased with alcohol. Tip! During operation, you should pay attention to the rotor contacts. If graphite dust and dirt have also accumulated between them, it must be carefully cleaned out.

How to eliminate a short circuit in the winding

Sometimes replacing brushes and other actions do not produce any results, and the vacuum cleaner continues to spark strongly. Usually the problem is an interturn short circuit of the commutator. There are two ways out of the situation - you need to either completely change the winding or replace the unit’s motor.

When a short circuit occurs, noticeable blackening appears on the collector plates

Rewinding an armature requires some experience and specialized knowledge in electrical engineering. Therefore, it is easier to send the engine for service or immediately purchase a new engine. This will be expensive, but buying just an anchor usually doesn't make sense. Its price is about 80% of the cost of the entire motor.

Selection of brushes

To reduce the cost of production, companies usually install the same motors on different washing machines. This unification helps in repairs because it reduces the range of spare parts.

When choosing in a store, just say the car model, and the seller will select the right part. The marking will help you, which must be applied to one of the sides. The dimensions are indicated on it. For guarantee, you can take a sample with you.

The brush material has almost no effect on the performance of the engine. It only affects the frequency of their replacement. Therefore, when choosing, decide how often you are willing to make repairs.

It is advisable to buy products from well-known manufacturers. Here is a list of the best companies:

Bosch;
Whirlpool;
Zanussi;
Beko.

In general, it is advisable to take brushes from the same company that made your machine. The quality of original spare parts is usually higher. But sometimes brushes from one manufacturer may be suitable for a washing machine from another company. For example, the carbon contact Indesit L C00194594 can be installed on most Indesit engines, as well as Bosch, Samsung or Zanussi. Take advantage of this.

Please inspect them carefully before purchasing. If you're lucky, you can save a lot. And if not, then start a new repair after just a few washes.

Here are some general tips.

The main thing when choosing brushes is the size. They are the ones who determine whether a graphite bar can be placed in the brush holder.
The set includes 2 brushes, and they are changed at the same time, even if only one is worn out. This is necessary to press them evenly against the manifold and extend the life of the engine.
Inspect the item carefully. Even small cracks and chips are unacceptable. Otherwise, it will quickly collapse during operation. The surface should be smooth and matte.
Buy spare parts only from specialized household appliance stores. There the likelihood of counterfeiting is minimal.
Many services cooperate with manufacturers. You can order the necessary parts from them and, in addition, receive detailed advice on repairs.

The motor brushes of power tools spark: the reason is that they spark strongly at the armature of a drill or grinder

Commutator motors are widely used in household electrical equipment. Small dimensions, lightness, and ease of operation determined their presence in grinders, rotary hammers, circular saws, and screwdrivers. The main disadvantage is increased wear of the brush-collector pair. The failure of this unit is predetermined by the sparking that occurs in it.

Electric motor design and operating principle

The operating principle of an electric motor is based on the interaction of a conductor with a current located in a magnetic field.

The magnetic field is created by the stator.

The main element of its design for a DC motor is a permanent magnet, for alternating current it is an excitation winding. The rotor (armature) has its own winding, to which voltage is supplied using a brush-commutator unit. The interaction of magnetic fields causes the rotor to rotate.

The collector consists of a set of contacts, which are copper plates located directly on the rotor. Micanite or mica cuffs act as insulators for each individual contact. Graphite brushes are sliding contacts pressed against the commutator.

Causes

Transient processes occur in the rotor windings due to intermittent mechanical contact of the brushes with the commutator plates, which causes the formation of small arcs.

Important: a fully serviceable engine does not exclude sparking during operation. There are other reasons that cause severe sparking and create the possibility of motor failure

Brush wear

With prolonged use or poor-quality brush material, they no longer press tightly against the contacts of the commutator. Due to poor contact, the engine does not gain speed or does not start immediately. A worn brush can be easily identified visually.

Sometimes it is not possible to correct the situation by replacing only the worn part. The brush holder and spring should be replaced.

Short circuit in the armature winding

The consequence of such a defect is uneven sparking on the collector. It will be stronger on some plates than others. Due to the presence of an interturn short circuit, the current in certain sections of the rotor winding will be stronger than in others.

Rewinding the rotor or replacing it will eliminate the problem.

Fault in the stator winding

A defect similar to a short circuit in the rotor winding occurs in the stator winding. You can check the presence by measuring the resistance of parts of its windings. If there is a strong difference, it is necessary to rewind the winding or replace it.

Pollution

The product of brush wear is graphite dust, which is an additional source of increased sparking. Dust accumulates between the plates, which creates additional conditions for the formation of sparks. Preventive cleaning of the commutator with sandpaper and removing dirt between the plates will keep it clean.

Brushes not installed correctly

If the brushes are deviated from the norm towards the commutator surface, a significantly larger amount of graphite dust is generated during operation. Misaligned brushes must be corrected.

Poor contact between brushes and commutator

The electric motor spends part of its operating time in overheating mode. Under such conditions, carbon deposits form on the collector. Poor contact leads to increased brush sparking and even more carbon deposits.

You need to use fine-grain sandpaper to clean the surface of the commutator. To increase the stripping effect, use a screwdriver. Clamp the engine rotor into the chuck and remove carbon deposits with sandpaper at low speeds. Afterwards you need to finally polish it on a felt wheel.

Mechanical problems

Mechanical reasons are caused by non-compliance with the requirements of design and technological documentation. Most mechanical causes can be eliminated by turning the manifold on a lathe. Refer this repair operation to a qualified technician. Here are some types of faults that may indicate a breakdown:

The surface of the collector is uneven;
The shaft runout exceeds the value specified in the technical documentation;
Individual collector plates protrude beyond a common level for all;
Insulation protrusion (mica);
The brushes in the brush holders move with jamming;
On the contrary, the brushes are inserted into the brush holders with a large gap, which creates vibration during operation;
The brush holders are installed far from the commutator;
Uneven tension of the springs, resulting in a difference in the pressure applied to the brushes.

Sparking on the commutator

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To extend the service life of the vacuum cleaner electric motor, you need to regularly carry out preventive measures to eliminate sparking in the area where the brushes come into contact with the collector lamellas.

The sliding contacts must be kept clean at all times and fit tightly against the polished commutator surface so as not to interfere with the free rotation of the rotor.

Brushes and bearings that have exhausted their service life must be replaced, and the surface of the commutator must be polished (cleaned well). It is important to take preventive measures in time.

How to understand that you need to change the brushes

Many people change brushes only after they notice strong sparking from the tool, as well as the appearance of a burning smell. Many craftsmen are not stopped even by these signs, and they continue to use the tool until it stops turning on. When is it necessary to change carbon brushes so as not to damage the structure of the power tool? There are the following signs for this:

Strong sparking - if signs of strong sparking appear, then it is necessary to disassemble the tool and inspect the consumables. Sparking is the first sign that consumables need to be replaced.
The appearance of a burning smell - if the smell of soot is heard when using the tool, it is recommended to disassemble the grinder and replace the graphite brushes
When the wear of the main part is over 30% -40%. However, it is almost impossible to determine their initial length, unless you measure it before installing the elements
When signs such as jerking or “growling” of the power tool appear

Devices are also subject to replacement if they have uneven wear and do not correspond to quality.

This is interesting!
It is not recommended to buy copper-plated brushes for a home grinder, as they will quickly damage the armature commutator due to the high copper content in the composition.
Copper-plated elements can be used on grinders that have a special coating on the collector plates. https://youtube.com/watch?v=Wt0n_ECSwvE%3F

How to replace it yourself

What could be easier than replacing the brushes on an angle grinder? However, here there are some nuances that should be taken into account so as not to damage the power tool. First you need to choose the right consumables. When choosing, you should rely on the model of the grinder or remove the installed brushes and measure their dimensions. Buy new elements using these sizes. It makes no sense to talk about how much such devices cost, since this is mere nonsense.

After the consumables are purchased, the brushes are replaced. In this case, first you need to look at the model of the grinder. Some manufacturers equip their power tools with special shafts for quickly replacing brushes. They are a plastic cap that is screwed in and out with a screwdriver.

If it is an angle grinder that does not have a special shaft for quickly replacing brushes, then you will need to disassemble the body to get to the consumables. When access is gained to replace consumables, further actions are performed in the following sequence:

Having gained access to the brush holder, it is necessary to disconnect the contact wire from it
Disconnect the contact wire, which is also connected to the brush holder
Retrieve erased element
Clean the area where the brush is installed, as it should move freely and without jamming
Install the new part in the reverse order of removal
Before installing the brush holder in place, it is necessary to inspect the commutator. If there are signs of carbon deposits, they should be eliminated
Carry out the replacement procedure on the other side in the same way.

Knowing how to change brushes on an angle grinder, you should immediately replace them. The more sparking devices on power tools are, the sooner they need to be replaced. When replacing, you must also take into account that devices need to be replaced in pairs, but not one at a time.

Summing up the work done, it is worth noting that there are many reasons for sparking brushes on an angle grinder, and in each specific case you need to look for your own breakdown. If it is not possible to determine the causes of sparking, then the tool must be shown to a specialist who will identify the breakdown and fix it. This is better than continuing to work with a faulty tool, which could burn out or short out at any moment. Only with the right approach to the repair and maintenance of power tools can you achieve long-term operation.