Warranty repair of power tools. Some malfunctions that may occur with a power tool Defective power tool

Fire has been known to mankind since primitive times. Most likely, it went to our ancestors as a result of natural phenomena, such as thunderstorms. Someone very observant and quick-witted discovered that fire not only frightens and burns, but also warms. Then everything went on increasing: people learned how to save smoldering coals, then they figured out what exactly could burn, and what of the materials around them did not burn, even if you cracked! When primitive people moved from fireproof caves to artificial dwellings, then the word “fire” had to be urgently invented. Fires destroyed dwellings, tools, food. People died in fires. And they continue to die to this day. Now in Russia, an average of 56 people die in the flames of fires in one day.

It turns out that today, when it is even ridiculous to compare our houses with the primitive dwellings of troglodytes, when ingenious means of fighting fire have been invented, when a powerful fire fighting service exists at the expense of the state, we cannot fight the fire element on equal terms.

Two main conclusions can be drawn from the above. First: fire is a formidable force, and second: not everyone has yet realized the danger of this threat.

In its physical essence, combustion is a fast-flowing chemical reaction with the release of heat and light. In a narrow sense, combustion is the process of oxidizing a combustible substance with atmospheric oxygen. Although in some cases combustion can proceed in the absence of oxygen. If gases are formed as a result of combustion, then the reaction is accompanied by a flame. A highly luminous flame is formed when solid particles, such as coal, are present in the combustion zone. And since carbon is an integral part of any organic compound, it is understandable why you can read by the light of a fire.

During combustion, active intermediate products are released, which greatly accelerate the process. Chain reactions begin, and only two factors become of primary importance for extinguishing a fire: timeliness and sufficiency. A cigarette butt thrown into dry grass is easy to trample. A bucket of water is sufficient to extinguish a small fire. But this is in the first seconds. And then the timeliness of our reaction and the sufficiency of means for extinguishing the fire are expressed in the cry: “Sentry, we are burning!” Even a ton of water is no longer enough, and the speed of the spread of the fire is accelerating like an avalanche.

It is in the high speed of the spread of fires that their insidiousness lies. No matter how highly organized the fire service is, no matter how modern and effective fire extinguishing means are, some time passes before the fight against fire begins, which, figuratively speaking, turns a simple cigarette butt into a disaster.

There are two ways of ignition of a substance: from an external source and self-ignition. In the case of an external source, everything depends on the magnitude of the initial thermal impulse (cigarette butt, match, torch) and the nature of the ignited substance. It is easy to set fire to a stack of straw with one match, because the amount of heat that a single match gives off is enough to start a combustion reaction for a flammable substance - straw. A raw log cannot be set on fire with a match.

In the case of self-ignition, the external temperature must be such that the reaction of oxidation of the substance with oxygen - combustion - begins. For paper, this temperature is only 218°C. The great American science fiction writer Ray Bradbury has a book called Fahrenheit 450. This is the same value for the ignition temperature of paper, only on a different scale. Imagine a book forgotten by a harmless stove. The stove heats up, the book heats up. At some point, the amount of heat coming to the paper will exceed the amount of heat that the paper gives off to the environment, and the result is a household fire.

For this physical reason, it is hard to believe that primitive people got fire by friction. Somewhere on the equator, this is quite acceptable. But try to produce so much heat by friction that in the damp and cold taiga 90% of your efforts do not disappear into the environment! But in the same taiga, a fragment of a bottle can be lying around, which will focus the rays of a modest northern sun on a very small surface of last year's needles. This can start a forest fire. The source of trouble is still the same - man!

Our houses are built from traditional and new materials. The traditional ones include: wood, red brick, gypsum, tiles, clay. Other materials - concrete, silicate brick, plastics, composite (consisting of different materials) building materials, metal - all these are the fruits of civilization, allowing you to build panel houses, monolithic skyscrapers, bridges, TV towers and much more.

In terms of fire safety, all materials are divided into fireproof, slow-burning and combustible.

Fireproof materials are those that do not ignite at high temperatures, do not smolder and do not char. Examples of fireproof materials: brick, concrete, metal, glass.

flame retardant materials are considered that, under the influence of high temperature, hardly ignite and continue to burn and smolder only in the presence of a source of fire. These materials include: composite materials (foam concrete with a heat-insulating layer, wood treated with flame retardants).

combustible materials are materials that ignite at high temperatures and continue to burn and smolder even when the source of fire is removed. In this group, of course, there are wood and composite materials based on it (chipboards, fibreboards, plywood). This also includes materials made of rubber, plastic, leather, linoleum, rolled roofing materials (roofing material, roofing felt).

The main physical characteristics that are important in understanding the properties of materials and their ability to withstand fire are:

strength;

specific gravity;

· porosity;

thermal conductivity;

fire resistance;

water absorption.

Strength is the ability of a material to resist fracture under an external load.

Specific gravity is the ratio of a body's weight to its volume. Numerically equal to density. Measured in g / cm 3.

Porosity- a property due to the structure of the substance, the presence of empty spaces between individual grains. Measured in percentage.

Thermal conductivity- the ability of materials to transfer heat through the thickness from one surface to another.

fire resistance- the ability of materials to withstand without destruction the action of high temperatures during fires.

Water absorption- the ability of materials to absorb and retain water. It is measured as a percentage as the ratio of the volume of absorbed water to the volume of the sample.

Having become acquainted with the physical characteristics of materials that interest us from the point of view of fire safety, we can comment on them as follows:

Durability is the main quality of a building material. There are no equals to monolithic reinforced concrete and metal. There is a steel Eiffel Tower in Paris, having a dead weight of 9 thousand tons! There are giant reinforced concrete skyscrapers in Dubai, Mexico City, New York and Sydney. The Ostankino Tower stands.

Specific gravity is important for creating a margin of safety. That is, the structure is able to resist heavy loads, when its strength is not spent on the fight against its own weight. This means that lightweight materials make it possible to count on greater stability.

Porosity is a wonderful quality. The best heat insulator is air. The more air-filled pores in the material, the lower its thermal conductivity and the more preferable it is for building houses. Foam concretes, expanded clay concretes, mineral wools and polyurethane foams are in the lead here.

Thermal conductivity is an extremely important concept, since not only the fire safety of the material, but also the rate of fire propagation depends on the ability to transfer heat through the thickness of the material. Metal is an excellent conductor of heat. And cold. Try licking a piece of iron in the cold. No, better not! Take my word for it - the tongue will freeze immediately. A piece of wood can be licked for pleasure without harmful consequences. An excellent illustration of the concept of thermal conductivity! Materials with a high degree of porosity, as a rule, also have low thermal conductivity, which is very good.

Water absorption - the ability of a material to resist fire by absorbing water. There is such a fire term - "spill". Occurred, probably, from "torrent rain". During pouring, smoldering fires are destroyed, surfaces are cooled. In order to turn 1 g of water into steam, you need to spend 80 kcal. So the fire spends its energy on vaporization, which we, in fact, achieved. Another important observation follows from this: water is an excellent means of fighting fire.

Acquaintance with water as a means of fire extinguishing should not be started from the "Cat's House", but much earlier. Somewhere around 200 BC, the first fire water pump was invented. In Russia, in 1803, the first fire station appeared, and in 1853, fire stations were already in 450 cities. The respected profession of a firefighter (axeman) and the honorary position of a fireman (fireman) appeared. Over time, a horse-drawn barrel of water was replaced by a tank car. The manual pump-rocking chair was replaced by high-performance pumps. But the principles of firefighting have remained the same, since the enemy - fire - has not changed at all over time.

Continuing to talk about water, it is worth noting that the speed and efficiency of fire extinguishing are proportional to the amount of water supplied to the fire. Pumps (pumps) mounted on fire trucks are capable of providing a capacity of 30 or more l / s, and mobile fire modules - up to 400 l / s. Water with its physical properties - density, viscosity, fluidity; in accordance with the laws of hydrodynamics, the possibilities of transmission over a distance are far from unlimited. Friction against the walls of pipelines, curvature, narrowing cause difficulties in the transfer of water and reduce productivity. From the bottom up, a powerful pump can supply water under pressure to a height of 100 m, but the laws of physics will not allow water to be sucked in using a vacuum from a depth of more than 7 m.

Water is supplied from the pump through flexible fabric hoses, at the ends of which there are connecting heads (locks) that allow the hoses to be connected to each other. Connections are quick disconnect, bayonet type. Bayonets (bayonets) were once attached to this type: to guns. Fire hoses are available in different diameters, but they are easily distinguished by the diameter of the suitable connection heads.

To connect several hoses or hoses of different diameters to the pump, there are branches, each branch (stroke) of which has its own valve. Branches are made of aluminum alloys for ease of handling.

To supply water to the fire, a barrel is attached to the end of the sleeve, which allows you to supply water with a jet or spray it.

When working with hoses, one should not forget that overloads occur at breaks, which can lead to a rupture of the hose, and in this case the water supply is stopped. With good pressure, it is extremely difficult for one person to hold the sleeve and direct the barrel in the right direction. He usually needs the help of one or two more people.

There are also large fire monitors, but only professional firefighters work with them.

In addition to water, compounds are fed into the fire flame that increase the extinguishing efficiency - foams, powders, emulsions. This is especially important in cases where flammable liquids are burning - oil, gasoline, etc. Water is no help here, since these liquids have a density lower than that of water, float to the surface and continue to burn.

Fires, in the center of which there are electrical installations under voltage, are extinguished with the help of compressed carbon dioxide, which is not a conductor of electricity.

Burning chemical reagents are extinguished with special compounds that react with the burning substance with the release of carbon dioxide.

Local fires are extinguished with fire extinguishers. Fire extinguishers are divided into foam, carbon dioxide, powder, emulsion.

Before using a fire extinguisher, you must read the text that is printed on its body. The fact is that a wide variety of brands and designs of fire extinguishers and extinguishing materials does not allow us to confidently judge the purpose of the device. For example, the latest emulsion fire extinguishers are marked: "Suitable for extinguishing electrical installations up to 1000 V." Such information should not be neglected, as well as the following: "Not suitable for extinguishing electrical installations under voltage."

In the rescue services, portable installations of impulse fire extinguishing "Igla" and "Igla-2" began to appear. Their use dramatically reduces water consumption when extinguishing local fires, eliminates such an unpleasant procedure as spilling, in which something that has not had time to burn gets wet through. Especially effective is the work with the "Needle" in apartments, where the use of traditional fire extinguishing methods leads to large material losses, not because of fire, but because of water.

In general, firefighting is a job for professionals. Rescuers who have not completed a special training course and are not certified to work as part of a combat crew are left with two important areas: reconnaissance of a fire and rescue of people.

The basic principles of reconnaissance in case of fire are purposefulness, activity, timeliness and reliability of the data obtained. Intelligence is the most important type of support for the actions of firefighters. And very dangerous.

That part of the intelligence, which includes clarifying the internal structure of a burning object, the possible number of people inside, the presence and quantity of hazardous substances (all this is found out by interviewing specialists, residents, employees and knowledgeable persons), requires speed, quick wit and efficiency. But, as a rule, it does not pose a particular danger. This type of intelligence is according to the possibilities and for one person.

Much more dangerous and responsible is reconnaissance, which is carried out inside a burning object, in conditions of smoke, the release of toxic gases, darkness, the danger of collapse of structures and the appearance of fiery whirlwinds. Such reconnaissance is carried out in groups of two people, and in cases where self-contained breathing apparatus is used, three people each.

A burning object is penetrated by any possible means - through window openings, by ladders and assault ladders, with the help of hydraulic lifts, ropes, free climbing on structures. This is where our ability to work safely at height can come in handy.

The task of reconnaissance is to determine the size and direction of the spread of the fire, the state of the object (danger of collapse, explosion, etc.) and, most importantly, whether there are people blocked by fire or affected by the fire. From here follows the continuation of the actions of the scout: to find ways to save people and determine the means of evacuation.

Scouts should always have lanterns, ropes, crowbars or hatchets for opening doors, insulating breathing apparatus at the ready.

If something is burning behind a closed door and a partition - and this can be determined by wisps of smoke from under the door, crackling paint, the smell of burning, a heated door or partition, a change in the color of paint or plaster - then you need to open this door very carefully while under protection of the partition or door panel (if the door opens in your direction), since the influx of fresh air to the source of a possible fire can cause a sharp increase in flame - a fiery whirlwind, the culprit of severe burns and the death of many firefighters.

When entering the room, you need to leave the door behind you from that one, and when leaving, close it. And be sure to try to remember your path. If there are local sources of ignition along the way that pose a fire hazard or threaten people, they should be immediately extinguished - this is where the portable Needle comes in handy.

In dark or smoky rooms, where the lights are ineffective, you need to move along the perimeter, along the right wall, without losing contact with it. This reduces the risk of getting lost in passages, branches and winding corridors. If smoke spreads across the floor, you need to move to your full height. If the smoke rushes up, you need to move bent over, and sometimes even crawling. The group moves one by one, without breaking away from each other. If at least one scout feels unwell, the group stops reconnaissance, helps a comrade to get out into the fresh air and renders assistance to him.

Victims found during reconnaissance must immediately begin to evacuate by requesting help by radio. Moreover, it is necessary to check all the premises, not trusting the information of unauthorized persons that there are no people in the room or cannot be. Checking the premises is stopped only after personally making sure that there really are no people in need of help in the room. A well-known survivalist Jacek Palkiewicz quotes a useful observation: “It should be remembered that children, frightened by a fire, can hide in the most secluded places, for example, under a bed, and almost always do not respond to unfamiliar voices.”

Rescue work is carried out simultaneously with fire extinguishing. Thus, the load on firefighters is removed and a field of activity for rescuers appears. If joint actions are insufficient or ineffective, all firefighters are involved in rescuing people, using all available ways and means to evacuate people.

The order of rescue is determined depending on the degree of threat from fire, smoke, explosion, collapse. First of all, they save children, then the sick, the elderly and women. Ways to save people include:

Independent exit of people along the routes indicated to them;

withdrawal of people accompanied by firefighters or rescuers;

removal of children and persons unable to move independently;

· evacuation of people with the help of retractable and attached ladders, lifts, rescue sleeves, slip-evacuators, ropes.

Particular attention is paid to those people who are afraid of evacuation from a height, are in an excited state, lose their self-control. In these cases, rescuers carry out evacuation with escort and organization of additional insurance. The behavior of the rescuers themselves is far from the last place: calmness, confidence and goodwill will help relieve stress and take control of the situation.

Of particular difficulty is the organization of rescue work in places with a large concentration of people - in discos, theaters, hospitals, kindergartens, etc. True, the main responsibility for the evacuation of people in these institutions lies with their leadership, but one should not expect too much that this will be:

carried out in a qualified manner;

· in a timely manner;

without panic;

without victims;

carried out at all.

The initiative to prevent panic, organized evacuation should be in the hands of rescuers until the last person is removed from the danger zone. Rescuers and firefighters are placed on the evacuation route to regulate the flow of people, stop panic, and help those in need.

In hospitals, schools, kindergartens, evacuation is carried out together with the attendants. The sequence, order and methods of evacuation are determined by doctors and educators. In the cold season, special care must be taken to ensure that children and the sick are dressed or wrapped in blankets.

In all cases when rescue work is underway during a fire, an ambulance should be called.

Most often, rescuers are involved in extinguishing forest fires. Here, the forces of professional firefighters alone are clearly not enough. Therefore, our qualified assistance here is most welcome.

The rarest case can be considered the fire of a forest from lightning. In this case, several unfavorable factors should overlap at once: prolonged drought, high temperature and low air humidity, lightning strikes a tall dead tree, strong wind. It is clear that a forest fire due to a thunderstorm is exotic. But a forest fire due to an anthropogenic (human) cause is an outrageously ordinary and sad event.

Forest fires are usually divided into lower, upper and underground.

In a ground fire, the fire spreads through dry grass, fallen leaves, and undergrowth. At the beginning of summer, as a rule, such fires do not cause much harm, since the forest floor is not yet dry enough. In the middle of summer or during a long drought, a ground fire damages the undergrowth and roots, and the damage from them is much greater.

A horse fire is much more dangerous due to the fact that crowns and branches of trees flare up during it, the fire spreads at high speed, “jumps” from tree to tree, even remote from the burning array. The high temperature of the fire forms its own ascending air currents, into which air is sucked in from the periphery - a source of additional oxygen. The fire covers large areas and is very difficult to extinguish.

The food for underground fires is peat, which lies under the forest. The thickness of the peat layer can reach tens of meters, and peat can smolder in the depths for years.

Ground fires try to surround and start extinguishing immediately from all sides. The edge of the fire is spilled with water, overwhelmed with branches, and covered with soil. Depending on the strength and direction of the wind, as well as depending on the type of trees, the density of the undergrowth, the air temperature, the best option for extinguishing tactics is chosen: from the front of the fire, from the rear, along the entire perimeter, or with retreat to a new frontier and creating a fire protection strip.

The undergrowth is cut down in it, needles, leaves are thrown into the ground. The loosened earth is moistened whenever possible. The main tools here are an ax and a shovel. Knapsack portable sprayers are inefficient. Let's remember the kind word "Needle".

Mounted fires are much more difficult to put out. Of course, all of the above methods of fighting ground fires are not excluded here, but for large crown fires, more effective measures are needed.

Annealing is one of these methods. When annealing along the crown fire front, that is, from the direction where the wind blows and where the fire spreads, a strip of 20-100 meters wide is burned. This method of stopping a fire requires special skill and careful observation, since fire is stopped here by fire, which is far from safe.

The speed of crown fire spread decreases at night. Therefore, the best time to fight a fire is late evening and early morning hours.

An underground fire is extinguished with the help of a large amount of water pumped into the hearth. There is a special technique for this. Underground fires are delineated by ditches that are filled with water.

The work of rescuers on such fires usually comes down to helping in felling trees. All trees adjacent to the ditches on the side of the fire are felled with their tops towards the fire. In order to put trees with a branched crown or inclined to the other side exactly in a given direction, braces from climbing ropes are used. Guys are fixed on the tree as high as possible and, if there are no other trees or stumps in the direction of the felling, the rope is pulled by hand. In this case, the length of the rope must be at least one and a half times the height of the tree. A chain saw makes a double cut (like a slice of watermelon) in the direction of felling to a depth slightly less than half the diameter. Pull the guy from the opposite side and make one horizontal gash, located 10-20 cm above the previous one.

Of course, having a rope attachment point, you can use a chain hoist, which will be more reliable, but, unfortunately, this does not happen often.

Climbing crampons with horizontal front teeth are used for climbing trees. Belay is organized using a piece of the main rope, one end of which is attached to the ISS belt, the second is circled with slack around the trunk and fixed to the ISS on the other side of the belt.

One of the main tools used in construction and repair is an electric drill. Even children know what it is, but few of the owners of this tool know how to repair it. Breakdowns happen with all tools, and if a drill breaks, then you can repair it yourself with your own hands. A step-by-step description of not only repair, but also diagnostics of the drill is described in the material.

Electric drill - remember the design of the tool

An electric drill is a type of tool that is designed for drilling different types of materials, including concrete and reinforced concrete. Only for this you need to use a tool with a hammer drill function or a hammer drill. How the tool works, you can find out if you disassemble it. Briefly about the design of the electric drill of Soviet and foreign production, is described below.

It should be noted that the design of modern drills of domestic and foreign production differs from the design of Soviet tools. These are only minor differences, which consist in the absence of a reverse on an electric drill, as well as impact drilling. So, structurally, an electric drill consists of two main parts - electrical and mechanical. The basis of the mechanical part includes the following structural elements:

1. Reducer - a set of gears, due to which there is a decrease in speed and an increase in the torque from the motor shaft
2. Chuck - an executive body that is designed to secure working nozzles
3. Bearings - bearing mechanisms of shafts and axles, ensuring their rotation
4. Impact mechanism - in electric impact drills, this device is part of the gearbox

The electrical component of any mains electric drill consists of the following elements:

• Collector-type motor, consisting of a stator (fixed part), a rotor or armature (moving part) and a collector (copper plates or lamellas through which current is supplied to the armature winding)
• Graphite or carbon brushes are a transmission device through which current is transmitted to the rotor winding. Brushes are consumables, and when, then this indicates their wear
• Start button - depending on the model of the electric drill, the switches are conventional and with a built-in speed controller
• Reverse button - there are no such devices on Soviet drills. This is a polarity reversal mechanism that reverses the direction of rotation of the tool chuck. Installed separately or built into the start button
• A ferrite ring is an element (filter) through which interference is smoothed out in the network
• Capacitor - a filter element that prevents interference from entering the network
• Power cord - the connecting link between the electrical outlet and the tool

The photo above shows the design of the drill with the main nodes. Sooner or later, it becomes necessary to repair the drill due to the failure of its individual components and mechanisms. To do this, it is required to initially inspect the instrument, identify the cause of the malfunction, and eliminate it. In more detail about what types of breakdowns of drills are, how to identify and eliminate them, is described in the material.

It is interesting! On old Soviet drills, there is no reverse mechanism and an electronic speed controller. Instead of an electronic regulator, a mechanical one is used, consisting of gears of different diameters and the number of teeth. This method of regulation is more reliable, since lowering the speed does not affect the power. However, this method of adjusting the speed is expensive, since it requires the additional use of a pair of gears. If one pair of gears is worn out, you can continue to use the tool. Below are photos showing the design of the mechanical speed controller of an old Soviet drill.

What you need to diagnose breakdowns of an electric drill

How to start troubleshooting an electric drill? Of course, from the first signs, by which it becomes clear where the breakdown is hiding, and which part needs to be repaired. It is easy to identify the mechanical malfunctions of the drill, but with the electrical part everything is much more difficult. Here you will need the appropriate tools, by which you can draw conclusions about the malfunction of certain components, parts and mechanisms of the tool. To identify breakdowns in the electrical part of the electric drill, you will need to prepare the following tools:

• Voltmeter or multimeter. Preference should be given to the second option, as it is more efficient and multifunctional.
• Device for measuring the interturn short circuit in the armature

To diagnose the mechanical part, you will need to perform the following manipulations:

1. See what specific function the drill does not perform
2. Inspect the integrity of the gearbox by first disassembling the tool body
3. Inspect the health of the bearings, as these devices often fail in the absence of lubricant
4. Check if the mode switch is working. If the device jams or fails, the tool will only work in one mode

In a drill, like any other type of power tool, various parts and mechanisms fail. The whole drill cannot completely break, but in any case, even when the mode switch is faulty, the operator will not be able to use the tool to its full capacity. That is why it is necessary to learn how to repair a drill with your own hands. This is not at all difficult to do, even if you have no experience. Therefore, you should not buy a new tool at the first malfunction, since the malfunction is sometimes easy to fix even without the need to replace parts. What types of breakdowns occur, how to fix them and what needs to be done for this, is described in detail in the publication.

Where to look for a breakdown in the electrical part of the most common malfunctions and their elimination

Electrical faults are the most difficult not only to identify, but also to eliminate. This is due to the fact that it is impossible to see the principle of the flow of electric current, but you can understand how the drill works. Based on the principle of operation of the electrical part, it is possible to draw appropriate conclusions about possible malfunctions. The principle of operation of the electric part of the drill is as follows:

• When the plug is connected to the socket, voltage is supplied to the electric motor
• The presence of a button in the design excludes automatic start when the plug is connected to the socket
• To start the tool, you must press the start button
• In this case, the contact is closed, and the current is supplied to the stator and rotor windings. The wires are connected directly to the stator, and to the rotor through brushes and a collector assembly.
• If we describe the principle of operation of an AC collector motor, then it lies in the fact that the stator winding acts as a permanent electromagnet, due to which the armature is repulsed. Just like that, the armature will not rotate, so it is also necessary to apply a biased current to its winding

The rotor starts to rotate at a certain speed. This speed depends on the magnitude of the voltage. To reduce the speed, regulators are used that work on the principle of increasing resistance. The greater the resistance, the lower the voltage value, and, accordingly, the lower the rotation speed. Knowing the principle of operation of the electric part of the drill, we will consider the main types of breakdowns and their elimination.

Drill does not turn on what to do

When connected to the network, there are no signs of tool life. Masters with experience had to deal with such a phenomenon more than once, but what if such a phenomenon happens for the first time? Disassemble, diagnose and repair the drill. Troubleshooting, when the drill does not turn on, begins with detecting the presence of voltage in the network. Trite, but true - often the reason for the inoperability of the tool is the lack of voltage in the network. The reasons for this may be scheduled repairs at the transformer substation, the operation of circuit breakers or damage to the power cable of the outlet. Take a multimeter and measure the voltage in the network.

If the outlet is working, then the next suspect for a malfunction is the network cable. Yes, it is also not eternal, and can be damaged during the operation of the tool. Do not try to find a breakdown visually, as this is a waste of time. Take the tester, and turning on the dialing mode, check the integrity of both cores. To do this, you need to disassemble the case, and alternately touch one probe to the contact on the plug, and the second to the wire connected to the button. The conductors are serviceable when the device "beeps".

How to perform a simple repair of a drill button with a speed controller

If the preliminary check showed that the mains wire is working, then it is necessary to continue the search for the malfunction along the current flow circuit. The next item in the troubleshooting queue is the button. On Soviet drills, such buttons are a simple mechanism by which contacts are closed. On modern tools, a round regulator is placed in the design of the trigger in the form of a washer with resistors, with the help of which the speed of rotation of the cartridge is regulated.

If the drill button does not have a regulator, then troubleshooting and troubleshooting is quite simple. To do this, you should disassemble it, inspect the integrity of the contacts and clean it with fine-grained paper sandpaper.

If an additional reverse switch is connected to the button, then it must also be checked by dialing. If it is determined that the failure is related to a button malfunction, then it is easier to replace it than to look for a malfunction and try to fix it.

Drill button why a capacitor is needed and how to check its serviceability

If you disassemble the button, you can find that in addition to this part a capacitor is connected (yellow or black block). Can this unit cause a malfunction or inoperability of the power tool? No, the capacitor is used to smooth out noise that occurs in the network. It serves as a filter element. If you disconnect it, then the drill and other types of power tools will work as before. However, it is not recommended to operate the tool without a capacitor, since its absence (or malfunction) leads to the failure of semiconductor elements.

There is an opinion that the capacitor is designed to create a phase-shifting effect. This is an erroneous opinion, since this element does not affect the operation of the tool in any way, but only excludes the ingress of radio interference back into the network.

How the drill button is connected

As experience shows, a drill malfunction in 60% of cases is associated with a malfunction of the shutdown button. Often an attempt to replace this element leads to the fact that all the wires get tangled, and the question arises - what to connect to in order to connect everything correctly. This is exactly what it is worth understanding so that the wires connected at random do not lead to a short circuit.

It should be noted right away that the buttons on drills can have a different design, but there are three types of their devices:

• Conventional without a regulator - when the trigger is pressed, the electric motor starts at full power. Typically, these buttons were used on old Soviet drills.
• Button with speed control - there is a washer on the trigger, the movement of which increases or decreases resistance. The greater the resistance, the lower the rotation speed of the cartridge
• Buttons with speed control and reverse - in addition, the device is equipped with a plate with a lever for switching the direction of rotation of the cartridge. The reverse is implemented by changing the polarity of the voltage supply to the rotor and stator windings

One of the most difficult connection schemes is the last option. However, if you look, then there is nothing difficult in connecting all types of buttons. The following diagrams for connecting the buttons of different drills - Bosch, Interskol and others - will help to understand this.

This scheme is also found in another version, as shown in the photo below.

The difference between these schemes is in connecting the wires from the reverse to the rotor and stator. Both options are correct and will work. It all depends on the instrument model. Observing the sequence of connecting the buttons of the drill, it will not be difficult to restore the tool to work. Below is a diagram in the form of an illustration of connecting a drill button to an AC commutator motor.

It is worth noting that the drill button fails not only due to the burnout of the contacts, but also due to the wear of the expanding spring. With a large output, the spring breaks, which ultimately leads to jamming of the device.

How to identify a malfunction of the brush assembly

Brushes, which are consumable items, fail on the drill. The brushes are made of graphite, and with their help, the current is transmitted to the rotor through the collector assembly. During operation, the brushes wear out, burn out, wear out and require replacement. The resource of brushes depends on various factors:

• Quality
• Collector health

It is possible to identify a malfunction of the brushes by such a sign as excessive sparking. If before the drill stopped starting, its excessive sparking was observed with signs of soot, then with a high degree of probability it is necessary to replace the carbon brushes. To replace, it is necessary to remove the elements from the brush holders, pull out the worn parts and install new ones in their place.

In addition to a malfunction of the brushes, it is necessary to pay attention to the condition of the copper lamellas of the collector. If signs of soot are observed on the copper base, as well as chips and other defects, then all this should be eliminated. If you can’t fix it yourself, then you should replace the anchor. The causes of carbon deposits on copper plates are excessive sparking from a power tool. In addition, with severe wear of the collector, there is a connection (short circuit) of the plates to each other, which is also unacceptable.

If the electric motor is faulty when it should be changed

A collector-type electric motor on a drill and any other tool is the heart of the equipment, which costs 60% of the total amount of the device. If the malfunction is related to the electric motor, then there are two ways to restore the drill malfunction - replace the entire engine or diagnose, identify the malfunction and fix it. It should be noted right away that diagnostics can be done independently, but it will not work to fix the malfunctions with your own hands. Here you will need to give the faulty assembly to a specialized workshop, but practice shows that it is easier to buy a new rotor or stator than to repair them.

Consider the principle of checking the health of the stator and rotor of the electric motor of the drill with your own hands:

1. A multimeter in the resistance measurement mode measures the value between the armature windings and the metal core. The presence of resistance indicates a violation of the integrity of the insulation
2. Marker designate the plate from which the test begins. With the probes of the tool, touch the plates one by one, and record the resistance value. In this case, the value between the plates should be approximately the same. A resistance difference of more than 10% is unacceptable, and indicates the presence of a break
3. Checking the interturn circuit. A special device can measure the presence of an interturn short circuit. It does not make sense to buy such a device on purpose, since if there is no breakdown of the insulation to the case or a short circuit between the plates, then with a high degree of probability it can be assumed that the armature is working
4. After that, the health of the rotor should be checked. Similarly, the absence of resistance between the winding and the core is checked.
5. Check resistance between windings. The absence of resistance indicates complete damage to the winding, and with a large value, breakdown can be assumed. Below in the video description it is described in detail how a step-by-step check of the health of the collector motor is carried out.

Stator failures are less common than rotor failures, but in any case, if the drill has recently worked in high load mode, then the engine fails in it. If it is determined that the motor on the drill is faulty, then it is easier to replace it than to repair it, and sometimes it is better to buy a new drill. The video below describes in detail how to find and fix electrical problems with a drill.

Breakdown of the mechanical part of the tool

If electrical failures are difficult to identify, then mechanical failures are much easier to deal with and cheaper. It is possible to identify mechanical defects even without the need to disassemble the instrument. If the drill cracks or the cartridge does not rotate, but the characteristic sound of the engine is heard, then there is a breakdown in the gearbox. When the nozzle does not hold in the drill, then there is a malfunction in the clamping cams. Bearings that cannot be repaired and require complex replacement can also fail..

Consider each type of malfunction, and the features of their identification with subsequent elimination.

1. The bearings have failed. Bearings usually last quite a long time, and the main reason for their rapid failure is lack of lubrication or lubrication. There are two types of failures in bearings - the complete destruction of the balls or wear. In case of complete destruction, the part must be replaced. When replacing bearings, there are no difficulties, so be sure to check their serviceability
2. Jamming of the gearbox assembly - here the breakdowns are associated with the licking of the driven or driving gear. Even in the process of work, a tooth can be chipped off, which ultimately will lead not only to a decrease in productivity, but also to the occurrence of a complete jamming of the transmission mechanism. If the gearbox fails, it is necessary to replace the gears. It should be borne in mind that on household tools, the gearbox can be represented by plastic gears. They must be replaced with similar ones, otherwise the installation of metal gears will lead to accelerated engine wear.
3. Repair of the percussion mechanism of a drill - unlike a hammer drill, this mechanism has a primitive design on a drill. The design consists of two parts, resembling a friction clutch. Shocks are created by moving a gear with notches. Notches on the rotating gear engage with teeth of a similar design on the body, and as if jumping, clicks are created - they are also blows. Malfunctions of the impact mechanism of the drill are as follows - licking of the notches, which ultimately leads to a decrease in productivity. More often, the notches are licked off on the movable gear, which must be replaced. Another breakdown can be when the shock mode of the limiter is not turned off. The reason is the wear of the metal ball, which, when the switch is moved, goes into the end of the shaft, thereby limiting the possibility of contact between the notches of the gear and the protrusions on the housing. To fix the problem, you should replace the ball in the design of the percussion mechanism

4. Malfunction of the executive element - cartridge. Drills use key-type chucks, which are characterized by increased reliability and efficiency. The clamping jaw on this part may fail and should be replaced. Detailed instructions on how to remove, repair and

Bearings and cartridge are minor mechanical failures, and failure requires an appropriate approach. Even if the diagnostics showed that the gearbox does not need repair and replacement of parts, then it must be dismantled, washed in gasoline and new grease added. Such manipulations must be performed regularly, depending on the frequency of use of the power tool. A detailed description of how to repair the impact mechanism of the drill is described in the video report.

Learning how to extend the life of a power tool from the moment of purchase

In order for the purchased power tool to serve for a long time and not fail at the most inopportune moment, it is necessary to ensure proper care for it from the very first day of purchase. This care includes doing the following:

• Store the tool exclusively in a dry and warm room. Exposure to moisture and low temperatures will cause condensation and damage to the electrical parts of the tool.
• Do not work with the tool for a long time under heavy loads, as this will lead to overheating of the windings and failure of the electric motor
• The presence of an impact mode does not mean at all that a drill can drill holes in concrete and reinforced concrete daily. The impact drilling function is an auxiliary one, and it is intended for infrequent use. For such purposes it is necessary to use
• With strong sparking of the brushes, it is necessary to replace them without waiting until the tool stops turning on at all

Consider when buying that drills are for domestic and professional use. If you choose a cheap household option, then you need to understand that such a tool is intended only for infrequent home use. Any repair in the house using a household drill will cause the tool to fail. If you need a drill in order to make repairs in the house, then you need to choose only professional options.

Looking into any tool store, you can be amazed not only by their cost, but also by their wide range - from dubious low prices to incredibly expensive ones. It should be noted that a low cost is not always an indicator of the poor quality of the product, and the high price of the device will not guarantee long-term operation of the tool.

The most common cause of power tool failure is the "human factor", or rather, the illiterate use of the tool. Moreover, any employee of the service center will say that every second case of contacting the service center can be attributed to a non-warranty case. And it is surprising that often customers use the device for its intended purpose, and the problem of breakage is their lack of skill in working with the tool.

Examples of the most common breakdowns and their causes

• Damage to the device or rapid wear of parts occurs as a result of improper operation of the device. Often this happens due to careless use, during which the user begins to overload the device. It is forbidden to put pressure on the device with body weight. The blows that the device performs will not become stronger from this, but the mechanisms of the device will wear out much faster.
• Rapid wear of bearings in the grinder. This is a common case that has nothing to do with the cost of the device and its brand. The reason for this wear in most cases is not a factory defect, but intensive use.
• Permanent burnout of the anchor in the chain saw. It should be noted that customers systematically address the same problem and assure that they have operated correctly, in accordance with all prescriptions. The verification process reveals banal errors that led to tool breakage that could have been avoided.

There are a huge number of such examples and can be considered as a warranty or non-warranty case, depending on various subjective reasons. However, in practice, it has been shown that in most cases, it is not the manufacturer but the user who is to blame for the breakdown of the device, which is confirmed by an independent examination.
We extend the life of the device.

• Before purchasing this or that product, you should carefully read the technical characteristics of the device, its description and reviews.
• Before using the tool, you should carefully read the instructions and the conditions under which the device can be voided from the warranty. In cases where the listed items or at least one seems strange and causes you doubts, then you should refuse to purchase this device.
• It is necessary to correctly correlate the technical capabilities of the device and the amount of work.
• When buying, you should check the presence of the seal of the seller, the authenticity of the warranty card, the availability and reliability of the date of sale, as well as the indication of the addresses of the ASC.
• No matter how trite it may sound, but in order to extend the life of any device, you must follow the instructions that are prescribed in the instructions. Careful attitude to the tool will allow you to extend its service life for a long time.

Portable power tool classes

Portable and mobile electrical receivers

Classification of premises by danger

Dielectric carpets and insulating pads

Footwear special dielectric

Dielectric gloves

1. Before use, inspect (damage, moisture, contamination), check for punctures by twisting

2. It is not allowed to tuck the edges. It is allowed to wear canvas gloves or mittens on top

3. Periodically rinse with soda or soapy water, followed by drying

1. Galoshes - up to 1 kV, boots - at all voltages

2. The color must be different from the rest of the rubber shoes

3. Before use, inspect for defects (delamination of parts or lining, foreign solid inclusions)

1. Carpets thickness 6±1mm

width 500-8000 mm; length 500-1200 mm

2. flooring at least 500x500 (gap between planks 10-30 mm)

3. do not test, inspect at least once every 6 months before use

With increased danger

• dampness (more than 75%)
• conductive dust
• conductive floors
• heat
• the possibility of simultaneous contact with the metal structures of the building that have a connection to the ground, technological apparatus on the one hand and to the metal cases of electrical equipment on the other.

Particularly dangerous premises

• special dampness
• chemically active or organic medium
• 2 or more high-risk conditions at the same time

Premises without increased danger- there are no conditions of increased danger

Damp rooms- relative humidity above 75%

Particularly damp areas-relative humidity close to 100%

Hot rooms- the temperature constantly or periodically (more than a day) exceeds 35°C

dusty rooms- according to the conditions of production, technological dust is released.

A room with a chemically active or organic environment- aggressive vapors, gases, liquids are constantly or for a long time contained, deposits, mold are formed.

Mobile electrical receiver- an electrical receiver, the design of which makes it possible to move it to the place of use for its intended purpose using vehicles or rolling it manually, and the connection to the power source is carried out using a flexible cable.

0 - electrical receivers with working insulation, without elements for grounding and not classified as class II or III

I- electrical receivers with working insulation and an element for grounding. The wire for connecting to the power source must have a grounding conductor and a plug with a grounding contact. The designation at the grounding contact is PE or white-green stripes or the word ʼʼearthʼʼ in a circle

II- having double or reinforced insulation and not having elements for grounding. Designation - double square

III- electric receivers for operation at safety extra-low voltage, which do not have either external or internal electrical circuits operating at a different voltage. Designation - rhombus with III

Extra low (low) voltage- not exceeding 50 V AC or 120 V DC.

When working with class I, gloves, boots, galoshes, rugs are used

When connecting a class I tool through an RCD, electrical protective equipment can be omitted.

To work with portable tools and hand-held electric machines of class I in rooms with increased danger, personnel with group 2 in electrical safety should be allowed

Before starting work with hand-held electric machines, portable tools and lamps, you should:

1. determine the class of the machine or tool from the passport

2. check the completeness and reliability of fastening parts

3. make sure by external inspection that the cable, its protective tube and plug are in good condition

4. check the clarity of the switch

5. perform (if essential) RCD testing

6. check the operation of the tool at idle

7. It is not allowed to use manual electric machines, portable tools and lamps that are defective or have not passed periodic checks or tests.

8. for machines of class I, check the serviceability of the ground circuit

Employees using electric tools and manual electric machines are not allowed to:

1. transfer machines and tools, even for a short time, to other employees

2. disassemble

3. make repairs

4. hold on to the wire

5. touch rotating parts or remove chips/chips until it comes to a complete stop

6. install the working part in the tool chuck and remove it from the chuck, adjust the tool without disconnecting it from the mains

7. work from ladders; for work at height, portable scaffolding and scaffolding should be arranged

When transferring a power tool from one workplace to another or a break in work, the tool must be disconnected from the mains with a plug. The tool should be carried by holding it only by the handle.

In the event of a sudden stop, the power tool or hand-held electric machines must be disconnected from the mains.

1. damage to the plug, cable or its protective tube

2. damage to the brush holder cover

3. fuzzy switch operation

4. sparking brushes on the collector, accompanied by the appearance of a circular fire on the surface

5. Grease leakage from the gearbox

6. the appearance of smoke or the smell of burning insulation

7. the appearance of increased noise, knocking or vibration

To maintain good condition, conduct periodic inspections of portable and mobile electrical receivers, by order of the head of the consumer, a responsible employee with a 3rd electrical safety group must be appointed. The employee must keep a log of registration, inventory accounting, periodic inspection and repair of portable mobile electrical receivers.

The frequency of checking portable and mobile electrical receivers, auxiliary equipment for them is at least 1 time in 6 months. The results of the inspection are reflected in the log book, inventory accounting, periodic inspection and repair of portable mobile electrical receivers.

The periodic check includes:

1. external inspection

2.Check idling for at least 5 minutes

3. Insulation resistance measurement

4. checking the health of the ground circuit

Repair of portable electrical receivers must be carried out by a specialized organization, after repair, the electrical receivers must be tested (increased voltage of industrial frequency: for a tool with a power of up to 1 kW - 900 V, more than 1 kW - 1350 V for 1 min)

Typical malfunctions of power tools - the concept and types. Classification and features of the category "Characteristic malfunctions of power tools" 2017, 2018.