Often the circuit breaker installed at the entrance to the apartment turns off. A common, but incorrect way to eliminate frequent AV shutdowns is to replace it with a device of a higher rating. The problem can only get worse, there is a possibility of damage to wiring or devices.

Circuit breakers - device and how they work

When the machine in the control panel goes off, it is turned on manually, but if this happens too often, they begin to think about the causes and ways to eliminate them. To understand more clearly why the current is automatically turned off so often, you should familiarize yourself with circuit breakers and their operation. Electric current is characterized by current strength and voltage. From these indicators power is calculated.

At a constant voltage, the current depends on the connected power. This pattern is used to protect wiring and devices.

The most common type of device that protects a home network is a circuit breaker. Each machine:

• designed for a certain number of operations;
• has its own sensitivity threshold; if exceeded, it turns off consumers;
• has a current limit.

Many people probably still use plugs, 6 A, 10 A, and so on. Automatic machines are also produced with the expectation of different current strengths. Circuit breakers are installed to protect against short circuits and overloads, which can lead to fire. So you can’t install machines and plugs of higher denominations, you can’t install bugs, they won’t be able to fulfill their protective function.

Another protection device is a differential relay (RCD). When a current leak occurs that is greater than what is specified in the device parameters, the relay breaks the circuit. RCDs are designed for a leakage current of 30 mA, but if the room is damp, a 10 mA leakage current is recommended. Consumers sometimes encounter leakage current when, for example, they touch a refrigerator and feel an electric shock; if there is no RCD on the panel, if there is one, the circuit breaks when the current leaks.

The next more advanced device is a differential circuit breaker, which combines the functions of a circuit breaker and a differential relay, that is, it is triggered by overload and current leakage. It is used to protect devices from high voltage and surges in the network. It is regulated by the minimum voltage or maximum response time when the specified voltage range is violated. An irreplaceable thing for a home network if the voltage is unstable.

Why does the machine trigger - possible reasons

Causes many reasons, from the simplest to the quite complex. Finding the reason why the plugs are knocked out is not difficult; it is not at all necessary to invite an electrician. The most common disconnection of a circuit in an apartment is when too many consumers are turned on, then the current load exceeds the maximum permissible for the AV. The protection device simply does its direct job - it breaks the circuit to prevent damage to the wiring.

Each machine is designed for a specific load: 6 A, 10 A, 16 A and more. If you turn on several devices of considerable power at the same time, the current can reach a limit greater than the AV can withstand, and the protection is triggered. The most common machines are 16 A, but they will not withstand turning on a washing machine, boiler, electric kettle, or air conditioner at the same time. A shutdown occurs and the wiring is protected from overload. If the machine has a thermal release, it will not be possible to turn it on immediately; it must cool down.

It is also possible that the shutdown occurs due to a malfunction of the protective device itself. Sometimes a defective product is purchased: the device indicates one rated current, but in reality it can withstand much less. At the same time, the housing heats up, which indicates that the thermal release is triggered. When the load current at which the machine operates and the rated current do not differ significantly, the device is in good working order. Its operation is affected by air temperature and product class.

Frequent operation of the machine occurs if the input contact is made poorly. The contact plate and the device itself heat up, and the thermal protection is triggered. Often the housing near the input terminals and the conductor insulation are melted, which indicates overheating due to poor contact, and the circuit breaker turns off the circuit. It is possible that there are no traces of melting, but the case is hot - which means the contacts are bad, but have not yet burned out.

If the device is connected, and the machine, which was previously working normally, instantly disconnects the circuit, the reason is most likely a breakdown of the electrical device. We turn it off, plug in the circuit breaker and another device into the same outlet. If it works, then the reason lies in a malfunction of the household electrical appliance. Repeated shutdown of the machine indicates other reasons.

The reasons for frequent knocking out of the machine sometimes lie in damaged wiring, which causes a short circuit. The phase and zero touch somewhere with bare sections of wires, the machine reacts to the short circuit and turns off the network. We turn off all consumers, turn on the AB. If the machine works, the reason is in the wiring. This is often one of the most difficult faults; finding the location of the short circuit is sometimes very difficult, especially if the wiring in the wall is damaged.

Eliminating the reasons for frequent AV shutdowns - what and how to do

If the light goes out, the sockets do not work, we go to the panel and look at the circuit breakers. Most often you just have to turn on the machine. Modern AVs send the switching handle down when triggered. To turn on the power, lift it up. In many houses there are still old Soviet-style automatic machines, in which the handle is in the upper position when activated. If there are many AVs in the shield, it is difficult to find one that has triggered. We turn off and turn on all the machines one by one.

If the network is overloaded, it will turn off automatically, but not constantly, but after a certain time period necessary for the protection to operate. Less often than not, lighting circuits are overloaded. Typically they are protected by one 10 A circuit breaker, which is sufficient in most cases. But if many additional lamps are installed, especially halogen or incandescent lamps, we install a separate automatic lighting unit.

Network overload from household electrical appliances is much more common. If you turn on 20 A consumers, and the rated operating current of the machine is 16 A, the circuit, of course, will break. In order to be completely convinced that the machine is triggered by an overload, we calculate the total current consumption of electrical appliances. It is especially good to do this at the moment of a power outage using a protective device. We sum up the power of all switched on devices, divide this number by the network voltage (220 V), and obtain the current strength in Amperes.

We compare the network load with the rating of the circuit breaker. In case of significant excess of current load from the rated circuit breaker, we use a smaller number of household appliances at the same time. If the house has old aluminum wiring with a small cross-section, we install an additional device - a priority current relay, which will forcibly turn off the non-priority device. An ammeter and voltmeter in the panel will allow you to visually monitor the load and voltage.

Poor contact occurs when the connection is poor and can occur anywhere - from junction boxes to lamps and sockets. We tighten the loose contacts; if they have not yet burned out, we replace the melted circuit breaker with a similar one. The contacts of the sockets weaken over time and burn out. Depending on the degree of damage, we tighten the contacts or change the socket. We inspect the lighting system - switches, lamps and troubleshoot problems in the same way as in sockets. Lastly, we look at the contacts in the junction boxes and fix the problems.

Household appliances may have various malfunctions, capable of triggering the circuit breaker. If this happens with a certain pattern, there is a high probability of this being the reason. We notice which equipment is activated when the machine is turned on, turn it off and see how the AV behaves without this device. If the shutdown does not occur, we look for a fault in the household appliance or send it in for repair.

In case of a short circuit, if the plugs are knocked out, we inspect the switches and sockets, check how the wires are connected to the terminals, tighten the screws if the wires are so loosely tightened that they can touch and short out. Next, we move on to the distribution boxes and check for any exposed wires that could cause a short circuit if touched. Then we check the quality of connections in lamps and chandeliers. The last thing we check is the wiring, which is mostly hidden in the wall. To detect a short circuit, we use a tester or call an electrician who has a thermal imager or other devices that can detect a short circuit in hidden wiring.

Other reasons for automatic network shutdowns are quite rare. The incandescent light bulb burned out, AB broke the circuit. There is nothing wrong, there was just a short-term overload, the machine responded. Sometimes it knocks out when the stabilizer is turned on, if at startup it creates a current higher than the rated current in the machine. If a shutdown occurs when the lighting is turned on, we check the lamps with a multimeter. After an apartment is flooded, it happens that the insulation becomes unstuck and a short circuit occurs. Be sure to check all wiring after flooding.

Installing a protective device - how to choose the rating

If it is necessary to install a circuit breaker of a different rating than the one previously installed, caution is required. An incorrectly selected rating can cause a wiring fire or permanent shutdown of the machine. If you use the method where the power of the devices is divided by 220 and do not take other factors into account, you can make a mistake. Be sure to take into account inside the house.

If the plug is knocked out, it is not necessary to replace it with a circuit breaker. After all, a traffic jam is the same machine with similar functions.

If the apartment uses old 2.5 mm 2 aluminum wiring, the insulation is stiff and cracked, we choose only a 16 A machine, no matter what devices we use. Possible option- we’re doing another one phase wire and install it on each circuit breaker with a rating of 16 A, because such wiring can only withstand 19 A. We choose a rating of 16 A for the machine so that it works reliably and the wires do not catch fire. At the same time, we turn on electrical appliances with a total power of up to 3.5 kW.

If the wiring is new copper, but the cross-section is unknown, you need to determine it. We take a small piece of wire, go to the store, compare it with electrical wiring samples. After determining the cross-section, we select the circuit breaker:

• We install a 10-amp circuit breaker at the input of the 1.5 mm 2 copper cable;
• with a cross section of 2.5 mm 2 - 20 A, but 16 is better;
• a 4 mm 2 cable will withstand a current of 25 A;
• 32 A is suitable for a 6 mm 2 cable.

We calculate the load for each line.

When we simultaneously change the circuit breaker and the wiring, the maximum rated current of the circuit breaker for urban high-rise buildings is 40 A, so that the wiring from the power line to the house is not damaged. We install a panel with separate machines for each line. We look at the power of the devices for each line, select a cable with the appropriate cross-section and only then select a circuit breaker of the appropriate rating.

The operation of a circuit breaker, or, as people say, a machine, is a reaction of protective equipment to an emergency situation that has arisen in the electrical wiring.

It is imperative to find out and eliminate the reasons for the operation of the machine so that the electrical wiring can function in operating mode. If you do not take measures to eliminate the malfunction, trying to re-turn on the circuit breaker after each operation, the problem will only get worse, which will lead to an emergency, fire and accidents.

Fault detection algorithm

In order to prevent the development of a tragic situation, you need to properly respond to the protection being triggered and know the algorithm for identifying the cause automatic shutdown. It is necessary to clearly know the reasons why knocks out the machine gun in the dashboard to respond properly.

Without going into at this stage In the electrical details of the processes, several main reasons for the protection to operate can be identified:

• There is a fault in the circuit breaker itself;
• Problems in the machine connection system;
• Instant network overload (short circuit);
• Network congestion that continues for a long time.

It is in this order that it is necessary to find out the reasons for the frequent knocking out of an automatic machine without obvious signs of a short circuit (SC) or prolonged overload, consistently making sure that there are no factors prompting the reaction of the protection system.

A simple protection system in a regular apartment panel

Possible network and equipment problems related to each item on the list will be described below. After making sure that there are no problems described above, you can move on to the next point.

Identifying a faulty machine

In case of frequent operation of the circuit breaker without visible reasons, you need to start troubleshooting with the distribution panel and the protection devices themselves. This check the least labor-intensive, and often problems are identified precisely at this stage.

A faulty circuit breaker can be detected without purchasing a new device and replacing it - it is enough to have circuit breakers connected to the panel with similar parameters.

Swap machines of equal power without changing the location of jumpers and wires

If a machine frequently breaks down, then to check it, you need to connect the group of users served by this device to an adjacent similar machine, and connect the freed wires from the line next door to this circuit breaker (swap the lines).

With this switching, a common cause of machine knockouts is automatically eliminated - loose contacts can become very hot, and the heat from them will be transferred to the bimetallic plate of the device, causing it to trigger falsely. When tightening the terminals this reason triggers can be eliminated even without the knowledge of the master. This nuance also needs to be kept in mind.

Poor contact not only causes false alarms, but can also completely damage the machine.

Due to the curvature of the case, a mechanical defect in the machine is possible, and it can be triggered by vibration. When disconnecting the wires and reconnecting a defective circuit breaker, the mechanical tension in the body can be removed, which will cause confusion for the technician due to the spontaneous elimination of the problem.

Tightening the contacts can relieve mechanical stress in the machine body

If another, working machine operates on a switched group of users, you should look for the cause in the electrical wiring. If on a new line the same machine frequently operates in the same way, then it will definitely need to be replaced or repaired.

Replacing a faulty machine

Reasons for machine wear

Despite the fact that circuit breakers are not dismountable by definition, folk craftsmen have learned to disassemble and repair them. Having drilled out the rivets using a drill, the machine body can be disassembled.

To disassemble the machine you will need a drill

Burnt contacts have a higher contact resistance, as a result of which they overheat, and the heat transfers to the bimetallic plate, causing it to deform and turn off the current.

Disassembled circuit breaker

Basic cleaning of burnt circuit breaker contacts can extend the life of the circuit breaker and prevent further false alarms. It must be remembered that contact burning occurs when the machine is turned on while all electrical appliances are connected to the network, that is, under load.

Burnt contacts increase the overall heating of the circuit breaker

Therefore, after the machine is triggered, it is recommended to turn off all electrical appliances, give the switch time to cool, and then turn it on again. If you try to forcibly turn on a still hot circuit breaker under load, its contacts will very quickly fail, which will cause frequent operation of the protection.

Contact of the bimetallic plate burnt due to the forced activation of the machine

Time-current characteristic of the machine

The function of the circuit breaker is electrical wiring protection from a short circuit accompanied by a high-temperature electric arc, and from prolonged overload, causing overheating of wires, melting and fire of insulation.

After checking the circuit breaker and the electrical installation in the panel, the reason for the frequent knocking out of the protection should be sought in the electrical wiring and connected equipment.

In the design of the circuit breaker, there are two elements that react to excess load in the electrical wiring.

Frames highlight elements that respond to excess current.

Without going into details of the design and characteristics of circuit breakers, which can be found in more detail at, two conditions should be highlighted under which the circuit breaker trips:

You should also check the heating of nearby circuit breakers. Large heat generation from them can shift the time-current characteristic of a problematic circuit breaker, causing it to operate faster and at lower current.

In itself, this heat generation from neighboring circuit breakers cannot cause frequent tripping of the protection, but it must be taken into account when general analysis operation of the machine and checking the electrical wiring it protects.

Short circuit detection

A short circuit is the contact of a conductor under phase voltage with a surface in contact with the ground. This may be the neutral wire or the grounding conductor of the PE electrical wiring, or the housing of grounded equipment.

A short circuit between the phase and neutral wires can also occur in the connected equipment itself.

Although many household appliances typically have built-in fuses, they do not operate quickly enough to allow the resulting electromagnetic pulse to affect the circuit breaker latch.

Short circuit on the electronic device board

Very often, a short circuit occurs when an electrical appliance is connected to the network. If at the same time, without delay, the circuit breaker trips, then we can judge with great confidence that there is a short circuit in the connected equipment.

Often the machine knocks out after turning on the incandescent light bulb - at this moment a characteristic sound is heard emanating from the lamp. Sometimes this happens due to the occurrence of an electric arc in the bulb. Electrical characteristics the arcs are close to a short circuit, so the machine reacts in almost the same short time of a few tens of milliseconds.

Photo of a light bulb exploding due to an arc between the electrodes

A short circuit may not always occur when the equipment is turned on. A short circuit can occur due to the fault of rodents or other animals that damage the insulation of the wires.

Damage to the cable insulation, which may cause a short circuit

The tripping of a circuit breaker is the first sign of problems in the energy supply of a house or apartment; their solution cannot be delayed.

In the case of infrequent outages, residents rarely turn to electricians to check or because they believe that there are no real complications. In most cases, the machine simply turns on again and everything returns to normal. But this approach is not correct, since further failures are guaranteed, because the real cause has not been eliminated, which means the wiring may burn out, the circuit breaker itself may melt, or an electrical appliance may burn out.

Let's look at the root causes of machine guns knocking out on the dashboard and ways to solve the situation.

Possible reasons for turning off the machine in the electrical panel

There are several sources of unstable operation of the machine. Some of them you can handle on your own, and some you need.

High wiring load

Network overload is the main culprit for knocking out the machine. The bimetallic strip inside the device heats up, opening the contact. This happens when several powerful devices are simultaneously connected to one electrical group (boiler, refrigerator, washing machine), and their total power reaches 17-20 Amperes. The machine is designed for a peak load of 16 Amps. The result of the simultaneous activation of a group of devices is that the circuit breaker trips, stopping the supply of electricity, maintaining the integrity of the electrical wiring.

There are four options to solve the problem:

install a more powerful machine, but there is a risk of ignition of the remaining old wiring: after all, the load remains the same and if the machine does not work, and the wires cannot withstand the greater load, then they may simply burn out;

avoid turning on several powerful devices at the same time;

distribute the power of the devices among different machines, but you will need to lay a new cable and install an additional socket;

replace the old wire with a new one of larger cross-section.

The last option is considered the most acceptable - it guarantees reliability and minimizes the risk of automatic shutdown in the future. The implementation of the plan is impossible without the help of a specialist.

Failure of a household appliance

The reason for shutting down the machine is the failure of used electrical appliances. It is necessary to determine which equipment is faulty. First, turn off household appliances that were turned on before the machine was knocked out. Then connect one by one and observe which device the automation turns off the power again.

The machine can knock out when the refrigerator is turned on:

failed compressor;

malfunction of the start relay;

burnt-out heating element of the evaporation unit of the “No Frost” system.

When the machine on the meter is knocked out simultaneously with the start-up of the electric boiler, the root cause is the following malfunctions:

damage to the heating elements: the coolant comes into contact with the coil located inside;

the power cable is broken;

There is a breakdown to the casing, which occurs when the internal wiring of the boiler is exposed.

Microwave ovens are characterized by the following problems that affect the operation of the circuit breaker:

defects in the operation of a transformer that converts voltage current from one type to another;

short circuit inside the magnetron.

Short circuit

A similar situation occurs when the phase wire is in contact with zero. The result is that the machine can knock out without load. This often happens after repair or installation work involving drilling holes in the walls where the cable is laid.

To prevent short circuits, it is necessary to inspect the areas that were affected during repairs. If damage to the wire is detected, it must be replaced with a new one.

Poor contact

If the automation starts to turn off without obvious reasons, the problem lies in the places where the wires are connected. The area of ​​the flaw is easy to determine: not far from the shield itself or near room sockets. First, you need to double-check all the clamps in the switchboard near the meter, especially if the input machine is knocked out. Next we move on to distribution boxes, sockets, and switches.

If, after rechecking all connections, it continues to knock out, then the problem lies directly in the malfunction of the automatic device, it requires replacement.

Other reasons for circuit breaker tripping

Knocking out can also be associated with a short-term increase in current when an incandescent light bulb burns out. Cases are especially common when installed switch designed for low power - up to 10 Amperes.

There are cases when the machine knocks out when the voltage stabilizer is turned on, which is due to technical features the latter. When they are turned on, a current is generated that exceeds the value of the existing circuit breaker. Remember that inexpensive stabilizers often fail, are unreliable, and therefore often break.

Despite the fact that at first glance it seems like the problem can be easily solved, repairs and replacements should only be carried out by a professional electrician. Otherwise, not only the electrical appliance may be damaged, but also all the wiring will ignite or melt.

The LuxEnergoService company provides comprehensive services for maintaining electrical networks in apartments and private houses. The craftsmen on our staff have the appropriate education and permits to perform electrical installation work, including high-voltage networks (more than 1000 V).

Automatic switches (CBs) are mandatory devices for any home electrical network to ensure the safety of its operation. Almost everywhere they have replaced the previously so common fuses - the so-called plugs. It’s understandable: automata (as AB is usually called in colloquial speech) - much more convenient to use, more compact, and in terms of reliability of protection they are still much higher.

But sometimes it happens that the circuit breaker, with some stubborn constancy, and, in the opinion of the owner of the apartment or house, for no apparent reason, refuses to work in the on position. That is, he is said to be regularly knocked out. Often this leads the owner to the idea of ​​​​the need to replace the switch, and also with an increase in the operating current rating. Stop! This is a fundamentally wrong and even extremely dangerous decision! First, you need to figure out the reason, find out why the machine knocks out. It just doesn't happen that way. Yes, there is a small probability that the AV itself is faulty, but most often this is a signal of serious problems in the electrical wiring or in the devices connected to it. That is, the machine, in fact, fully performs its task. And by turning it off, it seems to remind the owner - “Deal with the reason!”

The main functions of a circuit breaker, its basic structure and operating principle

This publication is certainly not intended for professional electricians. Its goal is to show the most ordinary person the possible reasons for the operation of a circuit breaker and “equip” him with the necessary knowledge to identify and eliminate shortcomings. Therefore, it would be useful to first briefly familiarize yourself with the design of the machine - this will make it easier to understand how it works and why it can be knocked out.

So, the vast majority of modern circuit breakers intended for installation in household networks are compact, modular devices for mounting on a DIN rail. The entire device is assembled in a plastic case with a characteristic rectangular shape. On the front side of the machine there is a power lever, markings with the main performance characteristics device. On the back side there is a special groove and a latch for mounting on a rail.

At the top and bottom there are screw terminals for connecting wires when installed in a circuit home wiring. The number of pairs of contacts may vary - from one to four. Accordingly, the switches themselves, according to this criterion, are divided into one-, two-, three- or four-pole. In a single-phase household network of 220 volts, two-pole ones are more often used - at the common input, and single-pole ones - on separate lines. Devices with three or four pairs of contacts are usually designed to operate on a three-phase 380 V network.

The dimensions of the machine are strictly standardized, and depending on the number of poles, it can occupy from one to four module spaces on the DIN rail of the distribution board (cabinet).

What is the purpose of a circuit breaker?

• One of its functions is quite obvious - it can work as a regular switch. That is, if necessary, depending on the installation location in general scheme, the owner has the opportunity to turn off the entire home (apartment) electrical network, or her separate plot. This is often required for preventive, repair, and electrical installation work. The function is certainly important, but still does not determine the essence of the operation of this device.
• The second task, and already a safety plan, is to protect the home network (or a certain section of it) from reboot. Alas, many consumers of electricity do not think at all about the fact that any conductor has a certain limit on the current it carries. And the picture when several quite powerful electrical appliances are switched on at once to one outlet through a whole “cascade” of extension cords and tees can be seen quite often.

Too much current in the wiring causes it to heat up, which leads to the appearance and fire of insulation, plastic housings of sockets or connected devices. And this is one of the common causes of fires.

A correctly sized circuit breaker is designed to prevent this situation. If the maximum load current in the line is exceeded, after some time it will de-energize.

• The third task is to instantly open the circuit in the event of a short circuit in the network. Deterioration, insufficiency or previous melting of insulation, violation of electrical installation rules in distribution boards and boxes or on sockets, problems with connected electrical appliances - all this can lead to the fact that the phase wire closes to zero without load.

The danger of a short circuit is difficult to exaggerate. The current in a closed circuit reaches values ​​of several thousand amperes, which, naturally, no wiring can withstand. That is, if the circuit is not immediately interrupted, large-scale melting and fires of wiring and devices are possible. And this is an almost guaranteed fire with very disastrous consequences.

This means that the task of the machine is to respond to a short circuit by breaking the circuit in the shortest possible time, measured in milliseconds, in order to prevent a large-scale accident.

The design of the circuit breaker is precisely designed to perform all these three tasks. Let's take a look at its design and how it works in emergency situations.

So, at the top and bottom of the circuit breaker there are screw terminals (item 1) for connecting the incoming and outgoing wires towards the load. In the illustration, just for the sake of compactness, the device is shown horizontally. In fact, the side on the right in the picture will be facing up. And most often it is to this terminal that the supply wire is connected.

The input terminal is connected to a fixed power contact (item 2). A movable power contact (item 3) works in tandem with it. It is the closing and opening of this pair that provides either switching or breaking the circuit. That is, the illustration shows that in this case the machine is in the off position - the contacts are open.

Internal switching in the switch, in addition to current-carrying metal parts, is carried out using powerful flexible conductors (item 4).

On the front side of the machine there is a switch lever (position 5). Most often, its lower position corresponds to turning off the device, and its upper position corresponds to turning on the device.

The lever is mechanically connected to a special mechanism, which is a combination of levers, springs and stoppers (item 6). When moving the lever to top position This mechanism ensures the closure of the movable power contact with the stationary one. And this contact is in a spring-loaded state, that is, when the stopper is acted upon under the action of the spring, the contacts will automatically open.

But this stopper, which keeps the contacts closed, can be influenced in three different ways. Firstly, simply by moving the lever to the lower position, that is, when manually turning off the machine. And secondly, the shutdown can be triggered by any of the two releases located inside - thermal or electromagnetic.

The electromagnetic release (position 7) ensures that the machine operates in the event of a short circuit. It is a coil whose turns are part of the total flow of current through the switch. The device is made according to the solenoid principle, that is, a spring-loaded metal core is placed inside the coil, which is mechanically connected to a movable power contact.

When a current normal for the electrical network flows through the coil, the generated electromagnetic flux is insufficient to overcome the spring force and retract the core. But if a short circuit occurs in the network, then the strength of the passing current instantly increases hundreds of times. Accordingly, this is accompanied by an instant increase in the magnetic flux created by the coil. The solenoid core is sharply retracted, which leads to the breaking of the lever mechanism from the stopper and, under the action of a spring, the moving contact being thrown away from the stationary one. It takes longer to write and read, but in reality, in a split second the chain breaks.

True, they usually try not to reach hundreds and thousands of amperes - the operation of an electromagnetic instantaneous release is usually calculated for a certain excess of the passing current relative to the specified rating. Based on these indicators, circuit breakers are divided into classes according to the so-called time-current characteristic, designated by Latin letters. The following classes can be used in a household network:

• B – operation when the rated current is exceeded by 3÷5 times;
• C – 5÷10 times;
• D – 10÷12 times.

The response time, depending on the size of the current excess, is determined by special graphs.

Typically, class B is used to protect specific leased lines. Several lines can be combined and protected in a panel by a class C machine. Class D is more suitable for powerful equipment with electric motors. IN living conditions used infrequently.

This distribution of machines by class and recommended installation location, by the way, also provides the necessary selectivity. That is, for example, in the event of a malfunction on a particular line, only its circuit breaker can operate, while the more “senior” one will remain in the on position, ensuring the normal operation of the remaining sections. It is clear that this greatly simplifies troubleshooting in the event of frequent protection activation.

The thermal release (pos. 8) is designed to ensure automatic shutdown when the permissible load current is exceeded. It is a bimetallic plate, which is part of the general circuit of the current passing through the machine. If the current is within the specified rating, the plate is motionless. But when an excessively large load is connected to the circuit, resistive heating of this plate begins due to an increase in current. Due to its bimetallic structure, it begins to bend when heated. And at a certain moment, the latch holding the lever mechanism in the on position will move out of place. And again, under the action of the spring, the fixed and movable power contacts will open.

True, here the operation does not occur instantly, but with a certain delay. That is, if the current excess is observed for a certain time. When assembling circuit breakers, they undergo calibration - for this there is a special adjusting screw (item 9). But after assembly, this screw becomes inaccessible, and you can knock it down factory setting the user will not be able to.

Such a delay is necessary, if only because, when starting up many devices, very significant current surges are observed, which then returns to the nominal value. This is especially true for appliances and household appliances equipped with electric drives - power tools, refrigerators, pumps and more. And so that the machine does not react by turning off every short-term start, this possibility is provided.

Contact break at large values current is usually accompanied by the occurrence of an electric arc. To prevent it from causing damage to the machine, it is equipped with a special arc extinguishing device (item 10). This is a separate chamber with a row of parallel metal plates installed in it. The arc breaks against them, loses its strength and becomes unable, for example, to melt the body or other internal parts of the switch. The gases formed during arc combustion are discharged through a specially provided window (item 11).

Finally, on the back side of the machine there is a shaped groove for installation on a DIN rail, and a movable latch that provides reliable fastening on it (pos. 12).

We hope the reader has clarity about the circuit breaker design. We can move on to consider the reasons for its frequent operation.

Why might a circuit breaker trip?

First of all, you should not perceive the operation of the machine as some kind of “tragedy”. If only because it was reassigned for this purpose. And in most cases, by turning off this device, it saves the home electrical network and the devices connected to it from large-scale accidents, which can result in very serious consequences.

The next thing is that troubleshooting will be much easier if your home network is properly organized. We are talking about the so-called selectivity of installation of automatic machines. That is, all internal wiring should ideally be divided into separate lines, each of which is protected by its own AV with a correctly selected rating.

The commercially available lines of circuit breakers may have a rated current of 6, 10, 16, 20, 25, 32, 40, 50 or more amperes. It's important to choose correct model for each group. So, for example, at the entrance to an apartment or a small private house a paired two-pole circuit breaker of 25, 32 or 40 amperes can be installed (depending on the cross-section of the wires at the input). Next, separate lines are organized for the most powerful home equipment(stove, oven, washing or dishwasher etc.), protected by their own circuit breakers with a rating of 16 amperes (this results in a load power of 3.5 kW). Similar lines are laid on socket groups located in the rooms and in the kitchen. And the separate lines unite lighting fixtures– a machine with a rating of 10 amperes is sufficient here.

What does this achieve? If a specific line is knocked out, and the rest continue to operate normally, then the troubleshooting area is sharply narrowed. Or, for example, knocked out introductory machine, but at the same time the remaining AVs with a lower operating current rating remained switched on - with a high degree of probability we can assume that the reason for the actuation lies directly in the distribution panel.

One more important note. It is not enough to install a circuit breaker with a rating adequate to the connected load. The cross-section of the wires on this line must also correspond to the same load. Otherwise, if, for example, a 16-amp machine is installed, but it is included in the line where it is laid aluminum wire with a cross section of 1.5 mm, the protection may not cope with the task. At least until the overload causes the wiring insulation to melt, followed by a short circuit.

Core cross-section copper wire, mm² (in brackets - aluminum)	Maximum current under continuous load, A	Maximum load power. kW	Rated current of the circuit breaker, A	Maximum circuit breaker protection current, A	Scope of application in home (apartment) conditions
1,5 (2,5)	19	4.1	10	16	lighting, alarm devices
2,5 (4,0)	27	5.9	16	25	socket blocks, floor heating systems
4,0 (6,0)	38	8.3	25	32	powerful climate control equipment, water heaters, washing machines and dishwashers
6,0 (10,0)	46	10.1	32	40	electric stoves and electric ovens
10,0 (16,0)	70	15.4	50	63	power input lines

Well, now – directly to the reasons for the protection’s operation.

Line overload

This is perhaps the most common reason for a circuit breaker to trip. And this situation only means that the device conscientiously coped with its task.

And the origins of the cause lie in the improper organization of the home electrical network or in the ill-considered operation of household appliances. It happens that too many devices are connected to one socket group at the same time. The total load, and therefore the current in the line, exceeds the rated one, and the thermal release in the circuit breaker is triggered, thereby protecting the line from emergency overheating.

At the moment the machine is turned off, you should immediately see which line is overloaded (if this is organized), and what specific load was connected to it at that time. As a rule, the picture turns out to be clear. And when one of the devices is turned off, the knocking out of the machine stops. True, when turning it on again, you have to give a pause of several minutes - the bimetallic plate of the thermal release must cool down, otherwise the machine simply will not turn on.

So, how is a problem like this solved?

• The first, of course, will be measures of the “administrative plan,” so to speak. That is, you should understand yourself and explain to everyone at home how and when you can simultaneously connect a powerful household appliances. Try to separate the devices you cannot do without into different outlet groups. Or even just keep in mind that, for example, if something is being cooked in an electric oven, you should not turn on the washing machine or a powerful water heater at the same time. In a word, prioritize the use of certain devices, the simultaneous operation of which leads to overload.
• The second way to solve the problem could be to purchase a circuit breaker with a rating one step higher (for example, instead of 16 - 25 amperes). But this is only possible if the cross-section of the laid wires allows, as mentioned above. If the section is insufficient, then the problem will only worsen and lead to even greater trouble.
• This suggests a third solution option - this major renovation with replacement with high-quality cables with a sufficient cross-section of copper conductors. This approach becomes especially relevant in houses or apartments where old aluminum wiring still remains, which is not at all designed for the modern level of electricity consumption.

If the wiring does not allow the installation of a machine of a higher rating, and the owners’ immediate plans do not yet include a major reconstruction of the home electrical network, all that remains is the rational distribution and use of the load. And, interestingly, in our time this can be solved, so to speak, at the “hardware level”. We are talking about special devices called load priority relays.

Such a device becomes especially relevant if the power limit allocated to an apartment or house is insufficient to simultaneously turn on all installed equipment. That is, there is frequent knocking out of the general machine at the input.

It works something like this. Household appliances are pre-distributed according to priority purpose. That is, the first group, say, includes those whose shutdown is undesirable under any conditions. Further, depending on the number of possible lines on the relay, other groups are “staffed”, and the priority of each subsequent one is less than that of the previous one.

If the permissible load exceeds the set rating, the group with the lowest priority will be turned off. If this is not enough, the next line will also turn off. But the most important devices will remain in operation, and there is no need to worry about overheating of the wiring. When the load normalizes, the relay will automatically turn on the lines in the reverse order.

The operation of the load priority relay, of course, requires a separate detailed consideration. And a publication on this topic will definitely appear on the pages of our portal.

Failure of household appliances

Another situation is when the connected load is clearly adequate to the rating of the machine. There is nothing to say that the line may be overloaded. But the defense works with “unshakable stubbornness.”

The reason may be a malfunction of the connected (connected) household appliance. In his electrical diagram Problems could occur that could lead to a short circuit.

It is not difficult to identify such a deficiency. First of all, you should, again, detect what exactly was connected to the power supply at the time the protection was triggered. After this, all these devices are turned off. Next, the machine starts up - and if the operation does not occur, then we can say that the accident area has already been localized in a certain way.

The next step is to sequentially connect previously switched off devices to the power supply. And, naturally, the “behavior” of the machine is monitored. The device whose connection to the outlet will trigger the protection clearly has internal faults and needs to be repaired. And you will have to stop using it until the problems are fixed.

So you should check all disconnected devices - the picture should be completely clear. But when checking, do not forget about increased security measures. Since there are reasonable assumptions about a malfunction of a device, a phase breakdown on its body cannot be ruled out. That is, special care should be taken to avoid electrical injury.

Home Wiring Defects

In the event that the entire load on the line is turned off, but the machine knocks everything out early, the reason may lie in a wiring fault. Here everything is somewhat more complicated - you will have to tinker a lot to find the defective area where the short circuit occurs.

They usually start with sockets and switches. When the line is turned off, the covers are removed from them, and then the condition of the terminals is first checked. It often happens (and more often if the wiring is aluminum) that the contact is weakened, sparking occurs on it, the insulation burns, from where it is only one step to a short circuit. And tightening the contacts can solve the problem.

This can also be caused by weakening of the spring metal contacts of the socket due to their wear. The issue is resolved by installing a new outlet. In this case, it is necessary to get rid of the burnt ends of the wires with melted insulation.

What to do with a socket that has become unusable?

It is always necessary to monitor the condition of the sockets - it is easier to identify a problem at the initial stage and prevent its development than to “shove it up” later. possible consequences. How to diagnose problems and read them in a special publication on our portal.

You should immediately check the lighting fixtures - short circuits also occur in their internal wiring. The defect may also lie in the cartridge - burnt contacts or even a short circuit at its terminals.

If the inspection of sockets, switches and lamps does not yield anything, we move on to working with distribution boxes. All wire connections should be checked very carefully - broken contacts in twists or loose terminals lead to sparking, overheating of conductors, melting of insulation and, as a result, a short circuit. It happens that the electrical tape previously used to insulate the twists unwinds, for example, due to a previous flood from the upper neighbors. And there should definitely be no exposed sections of wires in the junction box.

If everything is in order here, you will have to look for the damaged area hidden wiring. First, you need to try to remember whether, shortly before the accident was discovered, the wall was drilled (driving nails into it). It happens that such actions without preliminary “reconnaissance” violate the integrity of the wiring or its insulation, which leads to short circuits.

Troubleshooting hidden wiring is best done using special device. If it is not there, then you have to disassemble the connections in mounting boxes and ring each section of the network individually, identifying the location or short circuit of the conductors. And if there is no experience in such operations, then it is better to immediately call a specialist.

Well, if a damaged area is identified, nothing but replacing it will help the matter.

Video: Possible reasons for frequent tripping of a circuit breaker

Other possible triggering cases

In addition to those mentioned, there may be other reasons for the protection to trigger. They are not that common, but it doesn't hurt to know about them.

• It happens that a machine with a low operating current rating (6 or 10 A) turns off when the incandescent light bulb burns out. At the moment when the hair breaks, an electric arc can form, and this will be perceived by the switch as a short circuit.

There is no defect in this, and no special measures are required. It’s just that the time has come to abandon incandescent lamps and switch to more modern and economical light sources.

• Even before all the above operations, it always makes sense to immediately check whether everything is in order with the circuit breaker itself. Specifically, whether the wires in its terminals are tightened well.

If the terminal is not tightened sufficiently, sparking cannot be ruled out, which leads to heating first of the metal contact, and from it - of the bimetallic plate of the thermal release. Hence the protection triggers. But it’s better than the case ending up with such high heating that the body of the device itself begins to darken and then melt.

By the way, this is a fairly common defect when using aluminum wiring. This metal itself is very ductile and with constant pressure from the screw (plate) of the terminal it begins to “sag”. That is, contact deteriorates over time on its own. This requires regular tightening, which is naturally forgotten. So if your house or apartment still uses aluminum wiring, one of your priorities should be to reconstruct your home electrical system by replacing aluminum with copper.

Which cable should be used for home wiring?

According to current rules, wiring in residential buildings should only be carried out copper wires. Where aluminum remains, sooner or later a major replacement will still have to be carried out. A special publication on our portal will help you figure out the choice.

• Finally, if a thorough check of the home network and connected devices still does not reveal any defects, we can talk about a malfunction of the circuit breaker itself. It is clear that we are talking about a hidden malfunction - if the body of the machine is melted or, say, the lever is broken, then it must be replaced a priori.

And the reason for a hidden defect in a machine gun often lies in the desire of the owner, as they used to say at the Sukharevsky market in Moscow, to “buy for pennies.” That is, purchase a high-quality device for minimal money. Alas, this doesn’t usually happen in life.

A circuit breaker is, without exaggeration, a device for ensuring security - for your personal safety, for your family members, for your home, for all your acquired property. Is there any point in saving in such matters? Is it possible in one's right mind to purchase such a device cheaply second-hand or in a Chinese online store, where no one can guarantee the quality of the product and the correctness of its operation?

And even in a normal store, attention should first of all be paid to machines from well-known manufacturers who have proven high quality of its products. Alas, not everything is going well with some brands.

Among the domestic manufacturers, we can highlight the Kontaktor brand, which, by the way, belongs to Legrand, which speaks for itself. KEAZ machines are also a good solution in terms of price and quality ratio. You can find a lot of positive reviews about young products Russian company DECraft. But regarding IEK machines, despite their affordability and wide range of models, there are, alas, more complaints from users. than enough.

We will conclude the publication by posting a video showing a comparison of circuit breakers.

Video: Circuit breaker - which brand is preferable, "Schneider" or "I.E.K."

Content:

The main function of a circuit breaker is to protect the network from overloads and short circuits. Situations often arise when the owners of apartments and private houses have to solve the problem of why the machine in the control panel is knocked out and establish the reasons for such operations. Usually the whole matter is limited to replacing the machine with a higher denomination. However, such actions do not effectively resolve the issue, since the operation will occur even with an increased load on the wiring. As a result, home network lines may burn out and fail. To take the most effective measures, you need to know the reasons that trigger the machine in each specific case.

The machine knocks out in the apartment reasons

Most common cause When the machine is triggered, it is considered to perform its main function - protecting electrical wiring from overloads. Each model has its own release, ranging from 6 amps and above. When several powerful devices are turned on simultaneously, the current setting is exceeded and the protective device is triggered. Most often, overload is caused by a washing machine, water heater and other household appliances.

This problem can be solved in various ways. First of all, you should not allow powerful equipment to be turned on at the same time. If there is high-quality wiring with copper conductors and a cross-section of at least 2.5 mm2, it is possible to install a more powerful machine.

In some cases, when the machine knocks out, the reasons may be related to a faulty household appliances. Therefore, the machine begins to knock out when it is turned on at the same time. If there is a serious breakdown, even appliances such as a kettle or computer can have a negative impact. To check this fact, you should turn off all the devices one by one and see how the circuit breaker behaves. If it works normally, then the reason lies in one of the household devices, which will trigger when turned on.

A fairly common cause is a wiring short circuit. At some point the phase comes into contact with zero and the machine performs a second function - it protects against short circuits by triggering.

You can determine why the machine knocks out in a simple way. All devices must be turned off, and if the machine still works, then the wiring is faulty. It is recommended to start checking with sockets and switches, after which distribution boxes and lamps are checked, and at the very end the wires are checked. Usually the presence of a short circuit is determined using. However, especially difficult cases We recommend one capable of accurately and quickly detecting faults.

Sometimes unplanned operations occur due to the poor quality of the machine itself. The malfunction can be identified by replacing the device with a new device. In most cases, this allows you to effectively solve this problem.

When you turn on the light, the machine goes off

Quite often, at the moment the light is turned on, the input switch is knocked out, and the entire electrical network turns out to be de-energized. This malfunction may occur due to various reasons, and the most important of them is a malfunction in the connection of the chandelier, which uses conventional incandescent light bulbs with an E27 base. To identify possible malfunction You need to unscrew the lamps and inspect their bases for short circuits.

At the connection point of the chandelier, a contact burns out, which causes a short circuit and activation of the protective device. Sometimes it's all about the 12-volt transformer included in the design of the chandelier.

In some cases, the circuit breaker in the panel trips when the light bulb burns out. The machine knocks out under the influence of a short-term overload. With a low rating of 6-10 amperes, the likelihood of unplanned operation is high. Fluorescent and LED lamps are completely devoid of this effect.

The machine in the dashboard constantly knocks out

Quite often, owners of private country houses and apartments are wondering why the machine in the control panel knocks out without a load, in the absence of visible reasons. In addition to the factors already discussed, a similar situation often arises due to overloads in the electrical outlet network.

When drawing up a project and installing electrical wiring, it is impossible to determine with absolute accuracy the degree of load on each group of sockets. Usually there is a separate circuit breaker for 3-4 sockets. However, if there is a powerful protective device, the rated current of the connected sockets can be significantly lower.

In such a situation, an overload will certainly occur, especially if an iron, stove, microwave and other powerful equipment are simultaneously connected to the same group of outlets. As a result, the circuit breaker inevitably trips. It is possible to eliminate such cases by evenly distributing the powerful load between several outlet groups. If this is not possible, you should not connect several high-power consumers to the electrical network at once.

Sometimes it happens that the machine is knocked out and does not turn back on. Here the reason may be the thermal release, which gets very hot. To turn the device back on, just let it cool down and it will work normally again. The machine is often triggered by a faulty device that consumes increased current. As a result, the network is overloaded and the circuit breaker is knocked out. The solution to the problem, as already noted, is to turn on the devices one by one until the faulty one is discovered among them.

It happens that the machine itself is not connected correctly. Cores that are loosely tightened in the terminals lead to heating of this place and the operation of the thermal release. The reason is visible to the naked eye when not only the wire insulation becomes burnt, but also the body of the device.