Knocks out a machine gun: what could be the reasons? Why does the machine knock out in the dashboard? Why does the machine not work in case of a short circuit.

Surely most of our readers are familiar with the situation when the electricity goes out at home, while the neighbors have everything in order. First of all, you need to check the circuit breakers installed in the switchboard. Most often, it is their disconnection that causes the home network to de-energize. In this article we will talk about why an automatic machine knocks out in an apartment or house. The reasons for this phenomenon can be different, and it is important to know them in order to prevent unpleasant consequences associated with the failure of electrical appliances or fire wiring.

Features of the circuit breaker

To understand the reasons for the operation of the circuit breaker, you must first answer the question of what this device is for and what functions it performs. The features of the AV work are as follows:

The main task of the device is to protect the electrical wiring and household appliances connected to it from too powerful current that occurs for various reasons.
The device is mounted on a phase circuit, the break of which occurs when the bag is turned off. If the machine has two or more poles, then when it is triggered, the zero circuit will also open.

AB can de-energize the network both during manual shutdown and in the event of an emergency that can lead to damage to the circuit elements.

Knocks out a machine gun: what are the reasons?

Now we directly turn to the question of why the machine knocks out in the dashboard. The machine can operate for the following reasons:

Overload in the power grid.
Failure of one of the devices included in the circuit.
Breakdown of the lighting fixture.
Defective protective device.

Any of the listed reasons can lead to the fact that AB will knock out. Let's consider each of them in more detail.

Overload

This is the name of the situation when the current in the circuit exceeds the rated current for which the protective switch is designed. For a better understanding, let's give an example.

To work with outlet groups, AB are mainly used, the rated current of which is 16 - 25 A. This indicator corresponds to a total power of 3.5 - 5.5 kW. Suppose that an electric stove with a power of 3 kW, an electric kettle of 1.3 kW, and a microwave oven for 2 kW are connected to the outlet group, for protection of which an automatic switch designed for 25 A is installed.

If we add up the power of the listed household appliances, then we get a load value of 6.3 kW. Considering that the maximum load withstand by the protective device is 5.5 kW, the simultaneous activation of all three devices will cause the machine to knock out.

To avoid this, do not take lightly the calculation of the total load in the circuit. If connecting the device to an outlet group will result in an excess of the total power, it should be connected to a different circuit.

An example of incorrect calculation of the posting on the video:

Do not try to solve the problem by installing a machine with a higher power rating. If its rating exceeds the one that the electrical wiring can withstand in its cross section, problems are inevitable. In this case, under the influence of too much current, the cable will heat up until the insulating layer melts and causes a short circuit, and in the worst case, a fire. In this case, the machine will continue to supply current to the circuit until a short circuit occurs. Therefore, if a cable with a cross section of 2.5 mm² is used when laying the line, the AB rating for its protection should not exceed 16 A (for an aluminum conductor) or 25 A (for a copper conductor).

Household appliance breakdown

If you plug in a faulty home electrical appliance, then the likelihood that the machine will "shut down" is also quite high. Let's take an example how to find the device that caused the problem.

Let's say an electric stove, microwave and oven are included in the network in the kitchen. A machine gun was knocked out in this chain. To determine the cause of the problem, proceed as follows:

Disconnect all units from the network.
We turn on the machine. If it does not knock it out without load, the wiring and protective device are working.
We connect household equipment one by one. If, for example, when the stove and the microwave oven are turned on, the chain works, and when the oven is turned on, the machine knocks out, the oven is faulty, and it must either be changed or repaired

An example of diagnostics on video:

Some types of household appliances (for example, dishwashers or air conditioners) are connected directly to the network, rather than through an electrical outlet. Such devices must be disconnected from the protective device installed inside the switchboard - this is the only way to check them.

Malfunction of lighting devices

Now let's figure out why the machine knocks out when you turn on any lighting device. In any case, the reason is a malfunction of the latter, which may be as follows:

Short circuit in the lamp base. To find a faulty element, you need to unscrew them all and, screwing in one at a time, turn on the lighting device. When, after screwing in the next light bulb, when the light is turned on, AB is triggered, this means that the cause of the problem has been found. A discovered bulb with a broken base must be replaced with a serviceable one. Of course, if the only light bulb in the device burns out, and the machine gun is knocked out, the cause of the malfunction is obvious, and there is no need to waste time looking for it.

Please note that sometimes the bulbs burn out due to the fault of a faulty switch - this can also be accompanied by the operation of the protective device.

Burning contact between the power cable and the internal wiring of the device. To eliminate the malfunction, it is enough to clean the contact, and then insulate it with high quality.
A short circuit inside the transformer of an LED chandelier. If the inclusion of such a device leads to a knocked out machine, it is highly likely that this is the problem. To troubleshoot, a non-working transformer will need to be replaced with a serviceable one.

As you can see, the reason for switching off the AB when the lighting device fails is most often a short circuit. At the same time, the wiring does not have time to heat up to a critical level, therefore, the operation is triggered not by a thermal, but by an electromagnetic release.

Failure of the circuit breaker

Malfunctions in the machine itself can also cause a sudden power outage, but this happens very rarely, especially when it comes to models from well-known manufacturers. But if there is a suspicion of a malfunction of the protective device, it should be checked by connecting a new one, obviously working. It is also possible to disconnect the circuit from this AB and connect it to the adjacent bag in the switchboard. If these automata also work, the problem must be looked for elsewhere.

Even an outwardly serviceable machine gun can knock out. Video example:

The reason for the failure of the circuit breaker can also be its long-term operation, during which there is a natural wear of its components and deterioration of their technical parameters. This also applies to releases. As a result, the device may operate even if the conductor is slightly hot. This AB must be replaced.

What causes the differential circuit breaker to knock out?

A differential type circuit breaker can de-energize the network for the same reasons as a conventional one (if the wiring is very hot or a short circuit has occurred). But since in its composition, in addition to releases, there is an RCD, it also reacts to the leakage current, therefore, it is not so easy to find the reason for the operation of the difavtomat.

If such a device works for no apparent reason, a more thorough check should be carried out.

Inspect the breaker, if necessary, tighten the contacts. Check the condition of the wiring in the switchboard. If the phase conductor touches the grounded metal case, this can cause knocking out the differential circuit breaker, although it will not lead to a short circuit.

Let's assume that no faults were found in the panel. Consequently, there is a current leak in the protected electrical circuit. Its reasons may be as follows:

Defective electrical appliance. If it breaks through on its body, the RCD of the difavtomat is triggered, the task of which is to prevent people from being shocked.
A short circuit between the protective grounding and zero phase wires, which is sometimes done by inexperienced electricians.

Heavy thunderstorm. Powerful electrical discharges often cause knocking out of the differential protection device. In this case, it is better not to turn on AB until the thunderstorm subsides.
Worn insulating layer of old electrical wiring. In this case, the electric current leaks through microcracks and triggers the machine. Since such damage is poorly visible to the naked eye, and the faulty cable does not heat up, it can be difficult to detect the problem.
A sunken "Test" button on the device or a damaged housing part also triggers the device. In this case, the defective device must be replaced.
Installation of the machine not according to the scheme.

The differential automatic device should be checked from time to time by pressing the "Test" button with the load disconnected. A working device should turn off. If it continues to work, this indicates a violation of the protective function and the need to replace the device.

Why does the RCD knock out - clearly in the video:

Faulty wiring

The reasons for disabling the AV can be:

Worn cable insulation layer.
Poor contact at a switch or electrical outlet.

If the problem is in the switch or outlet, then to eliminate the malfunction, you need to open the element, clean the burnt place and connect the cable correctly. With worn insulation, especially when it comes to hidden wiring, it is not easy to find the problem.

In this case, a special device will help - a locator, with which you can detect cable damage, even if it is hidden in the wall.

Having determined the location of the malfunction, it must be opened and the malfunction eliminated, and then the groove must be repaired.

Conclusion

In this material, we figured out what reasons, in addition to an excessive heating cable, the circuit breaker can be triggered. Now you know what to do when the light bulb burns out with the simultaneous shutdown of the protective device, as well as how to troubleshoot if the wiring inside the electrical element burns out or if a household appliance fails.

Then any person more or less familiar with electrical engineering goes to the site to check in the electrical panel state of circuit breakers... Most often, troubleshooting is reduced to re-turning the machine on.

The fact of operation of a modern modular circuit breaker is easily determined: the handle is in the “down” position, a round “zero” mark is clearly visible on it. To turn it on, just turn this knob up, then a horizontal line will appear, and you can assume that the mission is completed.

Many apartments in the post-Soviet space are equipped with shields with machine guns of a slightly different type. Circuit breakers of the AE series and the like have slightly large dimensions, are fixed to the base with long screws and have an unpleasant property: when triggered, their handle remains in the same upper position. This makes it difficult to find a tripped circuit breaker, which must be turned off and on again in order to reapply voltage.

But all this is, by and large, trifles. A triggered automaton indicates some kind of malfunction, but we need to figure out which one.

Circuit breaker releases

First you need to find out at least in general terms, what is a circuit breaker and how does it work... Many people know that the automaton breaks the "phase". A multi-pole circuit breaker can also break a zero working conductor. But the machine can break the chain not only at the request of the owner, who turns the handle down. That is why it is an "automatic" switch that it can turn off automatically.

This is necessary in order to protect conductors and apartment electrical equipment from increased electrical current that can cause fire and destruction. The reason for the increase in current can be:

1. Network congestion... It can be caused by the inclusion of faulty electrical receivers, or electrical receivers, the total power of which exceeds the capabilities of the network. The latter can also be associated with the apartment, when one group has a large number of plug sockets. Each outlet individually may well not be overloaded, but their total current can reach values \u200b\u200bunacceptable for one machine.

For protection against overload currents in circuit breakers, it is used thermal release - bimetallic contact, the state of which depends on the temperature, which, in turn, depends on the flowing electric current. The setting, that is, the tripping current of the thermal release, can usually be adjusted within small limits.

2. Short circuit in the network... It can be caused by a malfunction in the electrical wiring or the failure of any electrical receiver. For new wiring, a short circuit can be the result of a wiring error, for example when connecting wires c. Physically short circuit is the electrical connection of the phase and neutral conductor in addition to the load. Since the resistance of the circuit in this case is limited only by the resistance of the wires, the electric current instantly reaches a very large value.

To protect against short-circuit overcurrents, the thermal release of the machine is ineffective: while the bimetallic contact heats up and breaks, the wires will almost certainly be damaged, and the electric arc will cause a fire. Therefore, modular circuit breakers always use electromagnetic release, the response speed of which is fractions of a second from the moment the current increases.

So, if a circuit breaker has tripped in your apartment panel, then you can, of course, turn it on again. However, systematic triggering indicates some problem that will have to be solved. What to do if the machine in the electrical panel goes off?

Short circuit in the socket circuit

With an instantaneous operation of the machine after it is turned on, there is every reason to believe that we are dealing with a short circuit - the thermal release will not work so quickly. You can verify the presence of a short circuit using - the resistance between the zero working bus N and the terminal of the circuit breaker in the event of a short circuit should be close to zero. Of course, such measurements can be carried out only with the machine turned off.

Once we are convinced that the cause of the operation is a short circuit, then it is necessary to find out exactly where it happened. The circuit breakers in the panel must be selected in accordance with the principles of selectivity, which means that it is the circuit breaker located closest to the place of the short circuit that must operate. In this case, the switch reacts only to short circuits in the part of the circuit that is located after it relative to the line.

Therefore, say, if only the input circuit breaker is triggered, then the place of the circuit is most likely located right in the input board. When closed within the apartment, a group switch is triggered and, often with it, an introductory machine. In this case, the input device can be safely turned on again and find out which group of electrical consumers is connected to the problem wire - this group will not work.

Having clarified this issue, you can turn off all these electrical consumers and re-enter the group machine into operation. If it did not work, then the reason is a malfunction of one of the disconnected electrical appliances. You can find a specific culprit either by turning on all electrical receivers one by one, or by measuring their input resistance. The second method is not suitable for devices with electronic control. A defective device must of course be repaired.

If all devices are in good working order, it is necessary to start inspecting the sockets that are part of the group: disassemble the plastic cases, check and tighten the terminal clamps. After the sockets, it is the turn of the boxes. They will have to be opened. And if the inspection does not reveal obvious malfunctions, then the wires must be disconnected in order to check the resistance between the cable cores separately. Such a check will already accurately determine which of the cables has a short circuit. The damaged line must be replaced, and the cores in the box must be re-connected using certified clamps.

Short circuit in the lighting circuit

If the tripped circuit breaker protects the lighting circuits, then the test can begin by inserting the machine with the switches off. The machine did not work - you can alternately click the switches in order to find out which circuit has a short circuit. Thus, we narrow the search area to the circuit of a group of luminaires introduced from one switch.

In this group, each luminaire should be carefully examined by unscrewing the lamps and examining the terminal clamps. A multimeter can measure the resistance between the phase and neutral wire from the side of each luminaire. In this case, you can determine the luminaire or cable line in which the short occurred.

If a short circuit is detected on all luminaires of the group, or is present in the network, regardless of the position of the switch, then the place of the short circuit is most likely the lighting branch box. It must be opened and checked in the same way as in the case of closing the outlet network. Well, if there is complete order in the box, then we ring out individual cable lines, disconnecting their ends.

Network congestion

As already mentioned, in the event of a mains overcurrent, the circuit breaker takes some time to operate. It usually takes a few minutes. Therefore, if the machine knocks out from time to time, then it may very well be that you are dealing with overload.

Lighting circuit overload - the phenomenon is quite rare, and in order to avoid it, use only lamps that are suitable in terms of power to your luminaires, and modernize the lighting circuit taking into account the power reserve. After all, the lighting circuits of individual apartments are often protected by one ten-amp circuit breaker. This is often enough, but when installing a large number of additional lamps in the panel, it is necessary to provide an additional automatic lighting for their power supply, especially if the lamps are halogen or with conventional incandescent lamps.

Overloading the outlet network - this is not uncommon. During the design and installation of electrical wiring in the house, it is impossible to accurately determine the load on each group. Therefore, for the convenience of residents, there are three to four sockets per group, which is turned on by one circuit breaker. And, despite the fact that the rating of the circuit breaker is usually selected according to the cross-section of the supply conductor and does not exceed 25 amperes, the rated current of the outlets can be 16 amperes.

There are all prerequisites for overloading, if all powerful electrical consumers, such as a kettle, iron, microwave oven and the like, are plugged into the sockets of the same group. Here, of course, the circuit breaker will trip. And to prevent this from happening, it is necessary to evenly distribute the powerful load between the groups, and in the absence of such an opportunity, not to connect several powerful electrical consumers to the network at the same time.

It happens that a faulty electrical appliance consumes an increased current, which leads to an overload of the network and tripping of the circuit breaker. It is not always possible to measure the current in domestic conditions, but if the thermal release is triggered only when one electrical receiver is turned on, and the rated power of this device does not exceed 2.5 kW, then it should be revised for faults.

Circuit breaker malfunction

It is not uncommon for the cause of the constant operation of circuit breakers to be the failure of the latter. Even among the new machines, a certain number of defective copies are allowed. Their inability to maintain the setpoint (and this applies mainly to thermal releases) is often revealed only during operation.

Therefore, with the systematic operation of the thermal release of the machine, before proceeding with radical methods of solving the problem, you can simply make a trial replacement of the machine with a machine of a similar value and characteristic.

Finally

In the article, we deliberately bypassed the moments when the machine was triggered - this is a topic for a separate conversation. For the same reason, we did not touch upon the situation when the differential circuit breaker trips.

But finally, I would like to remind you that the most popular way to solve the problem of a triggered machine - replacing it with a machine of a larger face value - is categorically unacceptable. Circuit breakers are devices that provide protection against fire and damage. Their face value is selected precisely for the purpose of ensuring safety. An arbitrarily chosen machine will not perform its functions and will not protect against dangerous modes of operation of the electrical network.

Alexander Molokov

Circuit breakers (AB) 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. This is understandable: automatic machines (as they usually call AB in colloquial speech) are much more convenient to use, more compact, and in terms of the reliability of protection they are still much higher.

But sometimes it happens that the circuit breaker with some kind of 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, it is said to be regularly knocked out. Often this leads the owner to the idea of \u200b\u200bthe need to replace the switch, and, moreover, 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. Yes, there is a small likelihood that the AV itself is faulty, but most often it is a signal of serious malfunctions in the wiring or in the devices connected to it. That is, the machine, in fact, fully fulfills its task. And by turning it off, it seems to remind the owner - "Deal with the reason!"

Basic functions of the circuit breaker, its basic structure and operating principle

This publication is clearly not intended for professional electricians. Its purpose 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 will be useful for a start to briefly familiarize yourself with the device of the machine - it will be easier to understand how it works, and why it can be knocked out.

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

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

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

What is the circuit breaker for?

One function of it is quite obvious - it can work as a conventional switch. That is, if necessary, depending on the place of installation in the general scheme, the owner has the opportunity to disconnect either the entire home (apartment) electrical network, or its separate section. This is often required for preventive maintenance, repair, electrical work. This function is certainly important, but still does not determine the essence of the operation of this device.
The second task, and already a protective plan, is to protect the home network (or its specific section) from rebooting. Alas, many consumers of electricity do not at all think about the fact that any conductor has a certain limit on the current it carries. And the picture, when several rather powerful electrical devices are connected to one outlet through a whole "cascade" of extension cords and tees, can be seen quite often.

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

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

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 the rules of electrical installation in distribution boards and boxes or on outlets, malfunctions in connected electrical appliances - all this can lead to the fact that the phase wire closes with zero no load.

The danger of a short circuit cannot be overstated. The current in a closed circuit reaches values \u200b\u200bof several thousand amperes, which, of course, no wiring can withstand. That is, if the circuit is not instantly interrupted, large-scale melting and ignition of wiring and devices are possible. And this is already a practically guaranteed fire with very dire consequences.

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

The circuit breaker is designed specifically to fulfill all three of these tasks. Let's take a look at its structure and how it works in emergency situations.

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

The input terminal is connected to a fixed power contact (pos. 2). A movable power contact (pos. 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 (pos. 4).

On the front side of the machine there is a switch lever (pos. 5). Most often, its lower position corresponds to switching off, the upper one - 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 the lever is moved to the upper position, this mechanism ensures the closure of the movable power contact with the fixed one. And this contact is in a spring-loaded state, that is, when the stopper is acted upon by 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 the machine is manually turned off. And secondly, tripping can be triggered by either of the two releases inside - thermal or electromagnetic.

An electromagnetic release (pos. 7) ensures that the circuit breaker trips in the event of a short circuit. It is a coil, the turns of which are part of the total cost of current passing through the switch. The device is made on the principle of a solenoid, that is, a spring-loaded metal core is placed inside the coil, which is mechanically connected to a movable power contact.

When current flows through the coil, normal for the mains, the generated electromagnetic flux is insufficient to overcome the force of the spring 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 generated by the coil. The solenoid core is sharply drawn in, which leads to the breakdown of the lever mechanism from the stopper and the rejection, under the action of the spring, of the movable contact from the fixed one. It takes longer to write and read, but in fact, the chain breaks in a split second.

True, they usually try not to bring up to 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. According to these indicators, the circuit breakers are divided into classes according to the so-called time-current characteristic, denoted by Latin letters. In the household network, the following classes can be applied:

B - operation when the current rating is exceeded by 3 ÷ 5 times;
C - 5 ÷ 10 times;
D - 10 ÷ 12 times.

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

Typically, class B is used to protect specific leased lines. Several lines can be combined and protected in the dashboard by a class C automatic machine. Class D is more suitable for powerful equipment with electric motors. In a domestic environment, they are rarely used.

By the way, this distribution of the machines by class and the recommended place of installation ensures the required selectivity. That is, for example, in case of malfunctions on a single line, only its automatic machine can be triggered, and the more “senior in rank” will remain in the on position, ensuring the normal operation of the remaining sections. It is clear that this greatly simplifies troubleshooting in case of frequent protection trips.

The thermal release (pos. 8) is designed to ensure the operation of the automatic shutdown when the permissible load current is exceeded. It is a bimetallic plate, which is a section of the general circuit of the current passing through the machine. If the current is within the specified rating, the plate is stationary. But when an unnecessarily large load is included in the circuit, then by increasing the current strength, resistive heating of this plate begins. Due to the bimetallic structure, it begins to bend when heated. And at a certain moment, the latch, which holds the lever mechanism in the on position, will move from its place. And again, under the action of the spring, the fixed and movable power contacts will open.

True, here the triggering does not occur instantly, but with a certain delay. That is, in the event that the excess current is noted for a certain time. When assembling the circuit breakers, they are calibrated - for this there is a special adjusting screw (pos. 9). But after assembly, this screw becomes inaccessible, and the user cannot knock down the factory setting.

Such a delay is necessary at least for the fact that when starting many devices, very significant current surges are noted, which then returns to nominal. 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 switching off for each short-term start, such a possibility is provided.

Contact rupture at high currents is usually accompanied by an electric arc. To prevent it from causing damage to the machine, it has a special arcing device (pos. 10). It 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 the burning of the arc are discharged through a specially provided window (pos. 11).

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

We hope that the reader will have some clarity with the circuit breaker device. You can proceed to consider the reasons for its frequent operation.

Why might a circuit breaker trip?

First of all, one should not perceive the operation of the machine as a kind of "tragedy". If only because he was reassigned for this. And in most cases, this device, by turning it off, saves the home power grid and the devices connected to it from large-scale accidents that can end up with very serious consequences.

Next, troubleshooting will be greatly facilitated if the home network is properly organized. We are talking about the so-called selectivity of the installation of machines. That is, all internal wiring should ideally be divided into separate lines, each of which is protected by its own AB with a correctly selected rating.

The lines of circuit breakers presented on sale can have a rated current of 6, 10, 16, 20, 25, 32, 40, 50 and more amperes. It is important to choose the right 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). Further, separate lines are organized for the most powerful household equipment (stove, oven, washing machine or dishwasher, etc.), protected by their own machines with a rating of 16 amperes (this results in a load power of 3.5 kW). Similar lines are laid on outlet groups located in rooms and in the kitchen. And separate lines unite lighting fixtures - here a machine with a rating of 10 amperes is enough.

What is achieved by this? If a specific line is knocked out, and the rest continue to work in normal mode, then the troubleshooting section is sharply narrowed. Or, for example, an introductory machine was knocked out, but at the same time the remaining AVs with a lower operating current rating remained on - with a high degree of probability, we can assume that the cause of the operation lies directly in the switchboard.

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

Copper conductor cross-section, mm ² (in brackets - aluminum)	Maximum current at continuous load, A	Maximum load power. kW	Rated current of the circuit breaker, A	Limiting current of the circuit breaker, A	Scope of application in a house (apartment)
1,5 (2,5)	19	4.1	10	16	lighting devices, alarms
2,5 (4,0)	27	5.9	16	25	socket blocks, floor heating systems
4,0 (6,0)	38	8.3	25	32	powerful climatic 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	input power lines

Well, now - directly to the reasons for the protection operation.

Line overload

This is perhaps the most common cause of a circuit breaker tripping. And this situation only means that the device has conscientiously coped with its task.

And the origins of the reason 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 outlet group at the same time. The total load, and hence the current in the line, exceeds the rated one, and a thermal release in the machine is triggered, thereby protecting the line from emergency overheating.

At the moment of turning off the machine, you should immediately see which line is overloaded (if organized), and what specific load was connected to it at that time. As a rule, the picture is clear. And when one of the devices is turned off, the knocking out of the machine stops. True, when you turn 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 this problem solved?

The first, of course, will be measures, so to speak, "administrative plan". That is, you should both understand yourself and explain to everyone at home how and when you can simultaneously connect powerful household appliances. Try to spread the devices, which 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 a 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 may be to purchase a circuit breaker with a rating one step more (for example, instead of 16 - 25 amperes). But this is possible only if the cross-section of the laid wires allows, as already mentioned above. If the cross-section is not enough, then the problem will only get worse and lead to even more trouble.
Hence, the third solution suggests itself - this is a major overhaul with replacement for high-quality cables with a sufficient cross-section of copper conductors. This approach becomes especially relevant in houses or apartments, where old aluminum wiring is still preserved, which is completely not designed for the current level of electricity consumption.

If the wiring does not allow the installation of a machine of a larger value, and the owners' immediate plans do not yet include a major overhaul of the home electrical network, only rational distribution and use of the load remains. And, interestingly, in our time it can be solved, so to speak, at the "hardware level". These are 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 a frequent knocking out of the general machine at the input.

It works like this. Household appliances are pre-assigned according to priority assignment. That is, in the first group, say, those are allocated, the disconnection of which is undesirable under any conditions. Further, depending on the number of possible lines on the relay, other groups are "equipped" as well, 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 be turned off. But the most important devices will remain in operation, and there is no need to fear overheating of the wiring. When the load is normalized, the relay will automatically turn on the lines in reverse order.

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

Failure of household appliances

Another situation is that the connected load is clearly adequate to the rating of the machine. Nothing suggests the possibility of overloading the line. But the defense works with "unwavering stubbornness."

The reason may be a malfunction of the connected (plug-in) household appliance. Its electrical circuit could have malfunctions leading to a short circuit.

It is not difficult to identify such a flaw. First of all, you should, again, detect what exactly was connected to the power supply at the time of protection. After that, all these devices are turned off. Further, the automaton is started - and if no operation has occurred, then we can say that the accident site has already been localized in a certain way.

The next step is to start sequentially connecting previously switched off devices to the power supply. And, naturally, the "behavior" of the automaton is monitored. The device, the connection of which to the outlet will trigger the protection, clearly has internal faults and needs repair. And its operation will have to be abandoned before troubleshooting.

So you should check all the disconnected devices - the picture should be outlined in complete clarity. But when checking, do not forget about increased security measures. Since there are reasonable assumptions about a malfunction of some device, then a phase breakdown on its case is not at all excluded. That is, you should be very careful not to get an 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 malfunction. Here, everything is already somewhat more complicated - you will have to tinker a lot to find the defective area where a short circuit occurs.

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

The weakening of the spring metal contacts of the socket due to their wear can lead to the same. 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 broken socket?

The condition of the outlets must always be monitored - it is easier to identify the problem at the initial stage and prevent its development than to “rake” the possible consequences later. How to diagnose problems and - read in a special publication of our portal.

The lighting devices should also be checked immediately - short circuits also occur in their internal wiring. The defect can also lie in the cartridge - burned contacts or even a short circuit on its terminals.

If the inspection of sockets, switches and lamps did not give anything, we proceed to work with junction boxes. All wire connections should be very carefully checked - broken contacts in twists or loosening in the terminals lead to arcing, overheating of the conductors, melting of the insulation and, as a result, a short circuit. It happens that the electrical tape previously used to isolate the twists has unwound, for example, due to an earlier flood from the upper neighbors. And there should definitely not be any bare sections of wires in the junction box.

If everything is in order here, you will have to look for a damaged section of hidden wiring. First, you need to try to remember whether the wall was drilled (hammering nails into it) shortly before the accident was detected. 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 a special device. If it is not there, then you have to disassemble the connections in the junction boxes and ring each section of the network individually, identifying the place or, or the 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 you identify a damaged area, nothing but its replacement will help the business.

Video: Possible Reasons for Frequent Tripping of the Circuit Breaker

Other possible triggering cases

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

It happens that an automatic machine with a low rated operating current (6 or 10 A) turns off at the moment the incandescent light burns out. The moment a hair break occurs, an electric arc can form, and this is 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, are the wires in its terminals well tightened?

In case of insufficient tightening of the terminal, sparking is not excluded, which leads to heating first of the metal contact, and from it - of the bimetallic plate of the thermal release. Hence - and protection operation. But it’s better that the case will end with such a high heating that the body of the device itself will begin to darken, and then melt.

By the way - a fairly common defect when using aluminum wiring. By itself, this metal is very ductile and at constant pressure of the screw (plate) of the terminal begins to "sink". That is, contact deteriorates over time by itself. This requires regular tightening, which is naturally forgotten. So if aluminum wiring is still used in the house or apartment, one of the priorities should be the reconstruction of the home electrical network, replacing aluminum with copper.

Which cable should be used for home wiring?

According to current regulations, residential wiring should only be carried out with copper wires. Where aluminum is preserved, sooner or later it will still have to be overhauled. A special publication of our portal will help you make your choice.

Finally, if a thorough check of the home network and connected devices still did 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 case is melted on the machine or, say, the lever is broken off, then it must be replaced a priori.

And the reason for the covered defect of the machine often lies in the desire of the owner, as they used to say at the Sukharev market in Moscow, "to buy for a penny a penny." That is, to purchase a high quality device for minimal money. Alas, this usually does not happen in life.

A circuit breaker is, without exaggeration, a safety device - your personal, your family members, home, all acquired property. Does it make sense to save money in such matters? Is it possible in your right mind to purchase such a device cheaply from your hands 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 salon-shop, attention should first of all be paid to automatic machines of well-known manufacturers, who have proven the high quality of their products. Alas, with some brands, not all is well.

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

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

Video: Circuit breaker - which brand is preferred, "Schneider "or"IEK ".

A circuit breaker trip can be caused by many different reasons, ranging from a malfunction of the product itself to a short circuit in the wiring. You can independently determine why the power release mechanism is triggered, and even an inexperienced electrician will not be difficult to do this. Next, we will tell the readers of the site why the machine knocks out in the dashboard and what to do to solve the problem!

Network congestion

The most common reason a circuit breaker (AB) turns off is because it just did its job - to protect the wiring from overload and further failure. When we considered, we said that each model has its own rated tripping current: 6, 10, 16, 25 A, etc. Now, if you turned on several powerful electrical appliances at the same time, the current of which exceeded the setting, do not be surprised why the circuit breaker in the house knocks out. For example, you have a 16A machine on your dashboard (a classic situation for old wiring) and at one moment you turned on the washing machine, air conditioner, electric kettle and boiler. The load on the network has increased markedly, as a result of which the AV turned off, thereby protecting the wiring.

There are several ways to solve the problem. The first and simplest one is to turn on powerful household appliances one by one so that it does not arise. The second is to replace the machine with a 25 amp. This is allowed only if the wiring can withstand the loads (copper, conductor cross-section of at least 2.5 mm 2). The third and most reliable one is for a new one, which will be able to withstand powerful household appliances.

The reason why the machine knocks out is clearly explained in the video:

What to do if AB is triggered under load?

We draw your attention to the fact that after the machine knocks out, if it is with a thermal release, it will not work right away. This is due to the principle of operation of the product. When the mechanism has cooled down (the time can reach several minutes), try to re-cock the lever to the "On" position.

Home appliance malfunction

If the machine knocks out frequently and at about the same period of time, it is most likely that one of the electrical appliances is faulty. For example, if you notice that the circuit breaker is triggered when you turn on the washing machine, electric stove or water heater, turn off this technique and see how the device behaves without electrical appliances. Doesn't it trigger? You need to look for a malfunction in one of the connected "culprits". We talked about that in the corresponding section of the site.

You can quickly find faulty equipment using the elimination method. Unplug all plugs and plug them in one at a time. On a device that is short-circuiting, the circuit breaker will trip under load.

If you disconnect all equipment from the network, and the machine turns off, then the matter may be in the wiring. What to do in this case, we will tell you further.

Wiring short-circuits

Another reason why AB often knocks out is. The phase in some place touches zero, as a result of which a short circuit occurs and the machine performs its second protective function - short circuit protection. If all consumers are disconnected from the network, and triggering occurs, it is necessary completely. This process takes quite a long time and, in addition, you need to be careful to find a fault.

First of all, you must disassemble all the sockets and light switches, check the quality of the conductor connections to the terminals. If the wires are loose, the screws must be tightened. After the sockets, go to the junction boxes. Make sure that it is of high quality, there are no bare areas that can shorten. After the boxes, you need to go to the lamps. Very often, novice electricians forget to check the chandeliers if the machine knocks out without load. The test technology is similar to sockets - you check the reliability of the connections.

Last but not least, you need to check the wiring, which is hidden in most houses and apartments (in the wall). It is best in this case to use a special device that can quickly and accurately find the short circuit. However, at home, hardly anyone will find it, so you can get out of the situation with a multimeter. We talked about wiring using a tester in the corresponding article. If this does not help, we recommend calling the wizard, who, using a thermal imager or other devices, will find a short circuit and eliminate it.

Out of order AB

Well, the rarest reason, which is also not excluded, is the poor quality of the machine, which knocks out due to the fact that it is defective. If you are sure that the wiring and household appliances are intact, and there is no overload, check the machine by replacing it with a similar one. We can confidently say that this will help fix the problem. In order to no longer face such a case in the future, we recommend that you familiarize yourself with and select one from the list.

What else could it be?

In addition to the above reasons why a machine gun knocks out in the dashboard, there are others that rarely occur. Let's briefly consider them too.

If the circuit breaker trips when the light bulb burns out, don't worry, it happens sometimes. The fact is that when the lamp burns out, a short-term overload occurs and if the rating of the machine is 6-10A, it, quite possibly, will knock out. This will not happen with LED and fluorescent lamps.

Sometimes on the forums you can find a situation where AB knocks out when the stabilizer is turned on. There are also some nuances associated with the operation of the device and your own inattention. The fact is that voltage stabilizers at start-up create a current that can exceed the rating of your machine, as a result of which it will knock out. There may also be a reason in the stabilizer itself. Cheap Chinese models are famous for their marriage.

If the operation occurs when the light is turned on, check the lamps with a multimeter. We also talked about that.

The banal reason why the machine turns off is the incorrect connection of this device. If the conductors are poorly pulled to the terminals, heating occurs in this place, as a result of which the thermal release can be triggered. A visual inspection will help determine the cause - the melted body and wire insulation. If the plastic has melted a lot, it is best to replace the circuit breaker. In case of minor damage, it is allowed to simply tighten the cores harder with a screwdriver.

Let's move a little away from the topic, but still note the important. If you have an introductory and group machines in your switchboard, it will be easier to find the reason. Knocks out AB at the input, without group ones? Check correctness. If a certain machine is turned off below the main one, then there is a malfunction in this group (lighting, sockets or a separately connected hob).

It happens that the problem arises after flooding an apartment. Water gets on the wire connections and if they are twisted with electrical tape, it is unstuck, as a result of which the contacts are closed. After the flood, it is imperative to make a wiring revision so as not to reach the situation when the circuit breaker starts to work.

So we have provided all the reasons why the machine gun knocks out in the dashboard. Please note that this situation can occur both in an apartment and in the private sector. Proceed in the same way, even if the circuit breaker on the pole trips! If you are not sure of your abilities, it is better to call a technician who will safely find the problem and fix it!

Interesting