Why does the machine buzz in the control panel under load?

A subscriber on my YouTube channel about electrical engineering asked me a question. Why does the machine in the dashboard knock out ? What to do if the oven, boiler, refrigerator, washing machine, stabilizer or boiler breaks down.

In this article we will see and think about what to do if, while simultaneously connecting powerful electrical consumers in an apartment or house, the circuit breaker knocks out the sockets in the panel.

I will show clearly why this is happening and whether in this case it is possible to replace the circuit breaker with another one designed for a higher current so that the circuit breaker does not turn off again.

Let me remind you that this article is part of a series of training articles on assembling an electrical panel in an apartment with your own hands from scratch to pro.

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The circuit breaker in the panel breaks without load: how to determine the source of the malfunction, and what to do if the switch on the meter constantly trips and does not turn on. If the light in the house goes out or the sockets stop working, you need to go to the distribution panel and check the circuit breakers. Ask, I'm in touch!

Circuit breaker hums

The machine in the panel can only buzz due to an electromagnetic release that protects the line from a short circuit. It consists of an electromagnet with a movable core. The release coil is connected in series with the contacts of the device, and when the current exceeds the protection setting, the moving part of the solenoid is attracted to the stationary part, which leads to the circuit breaker turning off.

The reason why the machine hums in the panel under load is that the current in the network is alternating with a frequency of 50 Hz. This causes the coil and core to vibrate in a manner similar to the hum of mains transformers.

Repair algorithm

If the switch shorts, you can repair it yourself, working in stages:

Line loss. The machine in the input panel is turned off.
Checking for voltage. This can be done by touching the indicator screwdriver to an outlet in another room.
Dismantling the device. You will need to remove the switch from the groove and remove the decorative trim. After this, the voltage is checked again, the screws on the sides are unscrewed, and the housing is removed from the socket.
Disconnecting cables. For two-key models, you will need to mark the input wire with a marker.
Disassembling the case and searching for contacts. The contact group is located above a plastic button mounted on screws.
Troubleshooting. The contacts are cleaned or the device is completely replaced.
Reassemble the case in the reverse order, reconnect the wires. The finished mechanism in the housing is returned to the socket box.
Turning on the machine in the panel and testing the switch for serviceability.

There is no need to repair the old switch - the light will flash again. Better change your device.

Useful tips Connection diagrams Principles of operation of devices Main concepts Meters from Energomer Precautions Incandescent lamps Video instructions for the master Testing with a multimeter

Why does the machine heat up?

The fact is that all household series operate on a thermomagnetic release. Under load, it heats up and as soon as the temperature exceeds the permissible value, the contact plate is deformed and activates the release mechanism, breaking the circuit.

To be fair, it should be said that all machines heat up under load and this is a normal phenomenon. The higher the load, the more the release heats up and the faster the circuit breaks. For example, if a 20A machine starts to pass 23A, then after half an hour it will turn off the network, at 25A this will happen after 5 minutes, and so on. There are several reasons for strong heating:

Poor condition of contacts - when the contact strip is loosened, the basic throughput deteriorates, causing it to become very hot;
Wear of the release mechanism - over time, parts wear out, their basic characteristics, including throughput, decrease;
Poor assembly - low-quality machines, as a rule, have characteristics lower than declared. They do not pass the maximum current for which they are designed, which is why they become very hot;
High load - the thermal release reacts to the overload protection, and it takes time to heat up, and the plastic case also heats up with it.

Each manufacturer has its own standards for permissible heating temperature, but usually it is from +55°C to +70°C, which is safe for use. You can always check the heating limit in the technical data sheet.

What to do if vibrations occur?

They often occur when current is applied to a coil or bimetallic strip, which creates an electromagnetic field that acts like an electric magnet on the metal parts inside. Electromagnetic influence provokes vibrations.

Even if the vibrations are almost imperceptible, this is also a malfunction. If you feel a slight tremor when you touch the body with your finger, it means the mechanism inside is defective, which is dangerous for further operation. In this case, it is highly recommended to make a replacement.

Purely theoretically, a circuit breaker can serve you for several more years, but there is no guarantee that the circuit will break during a short circuit. Moreover, constant vibration will over time weaken the connections more, causing the machine to jam, trigger falsely, or even fail. In any case, this is dangerous, so replace it with a new one as soon as possible. The only thing worse than vibrations is crackling. In this case, replacement is needed immediately .

Overload shutdown

First of all, it is necessary to analyze what load was connected to the electrical wiring lines that are connected to this machine. For example, a circuit breaker powers two outlets located in one of the rooms of the apartment. An electric heater was plugged into one outlet, and a vacuum cleaner was plugged into another. In this case, it is necessary to determine whether there was an overcurrent or not. To do this, it is necessary to compare the load current of household electrical appliances with the permissible load current of the circuit breaker (rated current).

The power of the electric heater is 2000 W, and the power of the vacuum cleaner is 1500 W. Having made simple calculations, we obtain the load current of these electrical appliances - 9 and 7 A, respectively, the total load in this case is 16 A. In the apartment panel, to protect the electrical wiring line feeding these sockets, a circuit breaker with a rated current of 16 A is installed.

Based on the fact that the load current does not exceed the rated value for the circuit breaker, we can conclude that there was no overload.

Otherwise, that is, if the load current is greater than the rated current of the circuit breaker, then the automatic shutdown of this device was due to overload.

It should be noted that re-closing the circuit breaker after tripping due to overload can be done a few minutes after it has been turned off. This is due to the fact that the thermal release (that element of the machine that protects against overload) is heated in the activated state, so in order for it to return to its original state it needs to cool down.

When turning off the circuit breaker, you can touch its body. If the housing is warm, this indicates that the thermal release has tripped, that is, a shutdown due to an overload in the electrical network.

The machine buzzes in the control panel under load

It happens that when you turn on a specific electrical appliance in the apartment, for example a multicooker or a lighting system using energy-saving lamps, or the power supply of a specific electrical appliance, the circuit breaker in the electrical panel begins to buzz. Moreover, this phenomenon is usually not associated either with the increased power of the connected consumer, or with the corresponding current approaching the nominal value of the machine. And it is associated with a certain power or with a certain household appliance.

In some cases, the hum disappears completely with increasing load power, and often the owner of the home has no complaints about the smell of burning... This means that it is not the arc that is humming inside the machine. And then what? Where does this hum come from? Is he dangerous? How to fight this phenomenon and is it worth fighting it at all? Let's think about this.

What's buzzing there?

Anyone who is familiar with the design of a circuit breaker knows that two protective tripping mechanisms are simultaneously implemented inside it: thermal and electromagnetic.

The thermal release mechanism is based on the gradual deformation of a bimetallic plate, which, heated by the overload current passing through it, bends; this process is relatively inertial, however, if the current is equal to the nominal value of the machine, then after a few seconds the deformed plate will press on the trigger mechanism, and the charged spring of the switch will open the circuit .

The electromagnetic release mechanism is designed for the event of a short circuit; it is designed to instantly open the circuit when, during a short circuit, the current through the electromagnetic coil reaches such a value that a spring-pressed iron core is sharply retracted into this coil, which, when retracted, presses on the same spring-loaded switch - the circuit again it suddenly opens.

So, since the bimetallic plate cannot hum, it does not participate in magnetization, but is only heated by the current passing through it, therefore the hum of the machine is associated with the coil.

Indeed, the iron core of the coil is always in the magnetic field acting in the protected alternating current circuit. If the core is not pressed securely enough by the spring, if there is some play inside the circuit breaker body, then under certain conditions this core will indeed emit a rather noticeable hum.

Why is it buzzing? What are these conditions?

Firstly, if the shape of the current in the coil surrounding the core is distorted by a pulsed load connected to the network, producing pronounced peaks from transient processes, then the magnetostrictive effect of such peaks will inevitably generate noise from the iron core of the machine’s coil.

Secondly, if the core, even in the cocked machine mode, falls into the saturation region, then it will also hum.

Thirdly, if the core still has a strong backlash, it can transmit vibration to the plastic body of the machine and to other elements of your shield.

Thus, when three conditions are combined: core saturation, strong backlash, and the presence of impulse noise, we will theoretically hear maximum noise.

Who is to blame and what to do?

The answer to the question about the cause of the hum is logical: the manufacturers and developers of the humming machine did not provide for all the possible nuances associated with how the core will behave when the machine is cocked. And there is only one way out here. If you don’t want to put up with noise, then you need to purchase a machine whose coil core does not hum from interference, backlash, or possible saturation, and if it hums, it’s not very loud. If the hum does not bother you too much, you can leave the humming machine alone.

Very often we are faced with such a problem as the sudden appearance of an abnormal operating sound from a circuit breaker in the panel room.

A slight hum from an electromagnetic starter surprises few people, and some even consider this effect to be its usual mode of operation, although this is not the case for new devices. So what should you do when your machine buzzes like this or buzzes?

First of all, remember that all machines installed in a panel under normal operating conditions should never make any sounds.

If this sound appears, then first of all decide what it sounds like:

hum

buzz

All your further actions will largely depend on this.

Such sounds appear when the machine is energized and under load. That is, current flows through it. Moreover, the greater the load, the louder the machine can make noise.

Let's look at the first fault, namely humming. If your machine makes a sound during operation like a starter or contactor, this indicates a defect or defect.

Do not look here for damage to electrical wiring, bad contacts, etc. A humming machine definitely needs to be changed.

Although this does not mean that his defense will not work as it should.

It can still shut down properly and operate during short circuits.

But how long it will work like this - a month or two, or it will burn out at any moment, you will never know in advance.

Moreover, if in the electrical panel it stands in one tight row with other intact circuit breakers, its sudden damage or ignition will lead to the failure of all neighboring switching devices.

Therefore, it is better not to delay the replacement and immediately buy another one. Do not listen to the advice of those who recommend simply knocking on the machine body with some blunt object.

For example, the back of a screwdriver. Apparently after this the sound disappears.

Replacing a machine is not such a difficult job, and many people do it even under voltage.

Also, do not try to repair or disassemble it yourself. Such modular devices are made disposable and cannot be restored at home.

They are assembled not with screws at all, but with rivets. These rivets can only be drilled out.

If you do this, you will see the following picture inside.

Troubleshooting when a circuit breaker trips: algorithm of actions

Without a special reason, the machine will never turn off, which means that there is an emergency situation that caused the circuit to be de-energized. Therefore, before turning it on again, you need to understand why it worked, detect the problem, and fix it. Only after this can the device be put into working condition. Let's look at the two most common triggers and the troubleshooting algorithm.

The machine responsible for the line of sockets knocks out

Immediately after the protection is triggered, all consumers should be disconnected from the sockets connected to this circuit breaker. It is worth estimating the total load that was connected. There is a possibility that there was an involuntary overload of the line. This must be taken into account, and in the future it is necessary to prevent the simultaneous inclusion of a large number of consumers.
Turn on the machine; if the protection does not trip again, then most likely there is a line overload or a short circuit in any of the electrical appliances. If the protection device does not turn on, then we can talk about a short circuit either in the socket contacts or in the supply cable itself.

Procedure if the circuit breaker trips without load

Inspect the sockets for burns; if any, disassemble or replace them.
A visual inspection did not yield anything, then it is worth assuming that there was an insulation breakdown in the supply wires.
Possible weak contact or malfunction of the machine itself. After fixing the problem or replacing it, you can try to apply voltage to the line.

Procedure if the machine turns on without load

Turn off the protection device and connect one of the electrical appliances that was previously connected to the same outlet.
Turn on the circuit breaker; if it trips again, then this device is faulty. If the operation does not occur, then turn on in turn all the consumers that were working before the protection was turned off. This way you can find a faulty electrical appliance.

Automatic protection is triggered, responsible for the lighting line

A fault in the lighting lines is usually detected when the chandelier is turned on. Everything is immediately clear here, but this situation does not always happen. What to do then? The algorithm of actions is simple and quite accessible to anyone:

Switch all switch keys to “Off” mode. This de-energizes the phase wire going to the lamps.
Unscrew the light bulbs, inspect them and the sockets - usually after a short circuit there are traces of soot on the lamp and base. Where such consequences are found, that is where the malfunction occurred. The lamp must be dismantled, the condition of the wiring and socket inspected, and replaced if necessary.
When nothing suspicious is found on the lamps and sockets, turn on the machine. If it works again, then you should look for a short in the wiring itself. This can happen either in the junction box or anywhere along the line. The second option is that the circuit breaker has turned on, which means we move on.

Now it’s time to turn on the lighting one by one; if the machine is triggered on some key, then you need to look for a breakdown in the wiring of this lamp.
If after turning on the switches the protection does not work, you need to screw all the bulbs into place and try to turn on the keys one by one. This will help identify the defective bulb.

When performing any troubleshooting work, be careful and careful, because repeated short circuits are possible. If you have the slightest doubt, it is better to contact electrical specialists who have experience in such work.

Why does a circuit breaker trip? The machine gun buzzes in the dashboard

Miscellaneous The machine in the dashboard is buzzing

Modern circuit breakers are not intended for repair because they are supplied in a non-separable housing. The manufacturer suggests replacing them, while at the same time, domestically produced AP type machines required not only disassembly, but adjustment; with some skill, you could assemble one completely working one from several faulty ones. From the article you will learn what malfunctions of circuit breakers occur and how to eliminate them. The machines in question are used in electrical circuits with voltages up to 1000 V to protect risers and supply lines.

How does the protection apparatus work?

To understand the causes of all malfunctions, you need to consider the design of the machine. It consists of a pair of power contacts, a thermal disconnector and an electromagnetic disconnector.

The thermal disconnector operates slowly, with a slight (up to 2 or more times depending on the time-current characteristics of a particular circuit breaker) exceeding the rated current. Electromagnetic - in case of a short circuit or the current exceeds several times, it is triggered in a fraction of a second. At first glance, it may seem that there is nothing to break here, but let's look at each of the mentioned malfunctions separately.

The main problems with automatic machines

The machine has only three main faults:

Knocks it out.
Doesn't turn off.
Doesn't cock.

The machine knocks out - this means that either suddenly, without obvious reasons, the voltage disappears, or when you turn on the load in one of the circuits, the power supply network is turned off. The machine may also not turn on in different ways:

When the lever is cocked, it immediately goes down, the voltage appears briefly or does not appear at all.
The lever is jammed and does not cock and does not work at all.
If you hear a burning smell or the wires are burnt out from the circuit breaker, you need to turn it off before starting the repair, but the lever simply does not budge, as described in the previous paragraph, only in the on position.

The machine kicks out for no apparent reason

Periodic tripping of a circuit breaker is associated with the operation of a thermal disconnector or voltage surges in the supply network. There is nothing you can do about the last reason, except perhaps install a voltage stabilizer at the input to the machine, but this is expensive. But shutdown via a thermal disconnector is associated with a long-term but insignificant excess of the rated current.

More often than not, this is not a faulty circuit breaker, but rather a misuse of the circuit breaker. First of all, you should find out what current it is designed for, this is written on the front panel. Then calculate the total current consumed by electrical appliances that are powered through it. If the current is not indicated on the devices, the power consumption should appear on them; in this case, divide the number of W by 220 V, then you will find out the number of Amperes through the machine.

If the result obtained exceeds the nominal value of the machine, it will open. If the machine hums or crackles, this is a sign that it is overloaded.

Solution: Reduce power line consumption, turn on powerful devices one at a time.

If the rating of the circuit breaker is selected correctly, the matter is different. The thermal disconnector is also thermal, so that it opens when overheated, and the source of heat can be burnt power contacts (as in the photo below) or wires that are not tightened in the terminal blocks. Both lead to an increase in contact resistance and heating, since the case is closed, there is nowhere for the heat to go, the thermal protection plate gradually heats up, and over time it will open.

Solution: Check the tightness of the wires, remove them, if necessary, clean them from oxidation and carbon deposits, and then retighten them. The contacts cannot be cleaned without disassembling the machine; it is better not to “treat” this malfunction, but to replace the circuit breaker. To disassemble it, you can drill out the rivets and open the body, but you risk not assembling it or assembling it with errors, with distortion and mechanical defects, which will complicate correct operation.

Overheating can also occur from heat sources located near the AV in the shield itself. Check the temperatures of the surrounding devices with your hand; something nearby may be heating up.

Trigger when load is turned on

If a malfunction occurs when one of the circuits is turned on, for example a light, the fault is most likely in the lamp or the wiring leading to it. A short circuit has occurred due to the integrity of the cable insulation or connections being damaged.

Solution: Diagnostics and repair consists of disconnecting the main line cable and replacing it with a temporary one; if it helps, then you have to inspect and repair the wiring.

Instant shutdown of the machine is associated with the operation of electromagnetic protection. It does not lock in the on position due to internal problems with the same electromagnetic protection. You can check the serviceability of the machine by replacing it with a known good one, with the same rated current and sensitivity - if everything works properly, this is the reason. If the circuit breaker does not reset without voltage, and there is no short circuit, it needs to be replaced.

Short circuit mode

If the machine is knocked out during a short circuit, this means that an electromagnet has been activated, which serves to instantly break the electrical circuit. In this case, the wiring does not heat up to a dangerous temperature.

When the power contacts open, an electric arc appears. To prevent them from collapsing, a chamber is provided to extinguish the arc. It is made in the form of a lattice of metal plates isolated from each other. On them the arc is crushed and extinguished.

Circuit breaker arcing chamber

Before turning on the machine again after a short circuit has occurred, its causes should be found and eliminated.

Electrical circuit breaker malfunction

Your circuit breaker trips periodically. The probable reasons for this are as follows:

Short circuit in the circuit;
Network congestion;
Damage to wires periodically leading to either a short circuit or overload.

First you need to diagnose the electrical network for overload and short circuit. If these faults are not detected, and the machine still turns off, then a malfunction of the circuit breaker itself is very likely.

Required Tools

When a spark appears in the switch, it is not necessary to call professional electricians. You can remove simple damage yourself.

indicator screwdriver – a model with a light bulb or electronic display is suitable;
a standard screwdriver, which is used to unscrew screws;
insulating tape;
fine-grained sandpaper;
pliers;
marker;
stationery knife for removing the insulating coating from the cable.

Before starting repairs, you need to know the design of the device. The switches are produced in a plastic case and have internal operating units and a frame. It is attached to the device with screws or latches. The main mechanism is located in the socket box and is secured with spacers or screws.

To make the contacts easier to access, you will need to remove the outer part from the switch.

Why the machine knocks out - we’ll look into the possible reasons when turning it on and in the control panel

A breakdown typical of budget models. The button operates on the principle of soft start, which, in combination with low-power automatic machines, provokes sparking.

Expert opinion

It-Technology, Electrical power and electronics specialist

Ask questions to the “Specialist for modernization of energy generation systems”

Reasons why a machine in an electrical panel knocks out Let us remind you that if the protection has tripped, in order to avoid more serious consequences, you should not postpone the inspection of the electrical network until later. Ask, I'm in touch!

The machine crackles under load

The crackling noise heard from the device always indicates the presence of sparks. Most often they occur when the moving and fixed contacts or terminals at the place where the wires are connected are worn out.

If in a working device all connections are tightly adjacent to each other, then when the connection terminals or contact group burn out, the electric current passes through soot, an air gap or point contact of conductive elements.

The flow of current through damaged areas is always accompanied by heating and further destruction of the connections, and if this process goes far enough, then sparks and the accompanying crackling noise are added to it.

Therefore, such a sound indicates the need to immediately turn off and replace the circuit breaker. Otherwise, it is possible not only for the device to fail, but also for it to catch fire and destroy the entire electrical panel.

The machine in the dashboard is humming or buzzing - 2 solutions to the problem and what to do.

Is it worth changing it right away, or is the reason not in it at all, but in the electrical wiring or connected load? Let's take a closer look.

First of all, remember that all machines installed in a panel under normal operating conditions should never make any sounds.

If this sound appears, then first of all decide what it sounds like:

hum
buzz