What should I do if my circuit breaker buzzes, crackles, or gets hot?

What causes the buzzing, and what to do in such a situation?

The fact is that alternating current flows in the network with a frequency of 50 Hz, which means that electrons move along the core in uniform waves occurring 50 times per second. Due to this movement, vibration of conductive parts occurs, the sound of which you hear.

The human ear detects any sound (air vibration) in the range from 20 Hz to 20,000 Hz. Microvibration at a frequency of 50 Hz is quite perceptible to our ears.

Oscillations occur due to poor contact of conductive parts. This problem often appears due to manufacturing defects or shocks and falls during transportation, careless storage, etc.

Usually, a long beep does not mean that the protection will fail at a critical moment, but still the characteristic sound indicates a malfunction. In this case, it is better to make a replacement, even if you checked the functionality yourself and an electrician you know said that “it’s okay, it’s normal.”

Any, even minor, malfunction often causes the release to fail in a critical situation.

Considering that a circuit breaker, even from a good German brand, is now easy to buy for just $5, it’s better to do so. You can easily verify this - on the website of the Axiom+ online electrical store there are always current prices for German Hager automatic machines. This is a small price to pay for protection against overloads and short circuits, which often cause fires.

Along with the humming, sometimes a slight shaking of the body is also felt.

The machine knocks out when you turn on the old machine

There may be several reasons:

The machine is outdated and requires replacement.
Problems with electrical wiring (frayed, condensation appeared). You can't do it without an electrician.
The network is overloaded. If you turn on several high-power household appliances (electric stove, air conditioner, iron, electric kettle), the machine may work. Try to unload the network by turning off unnecessary devices. If it doesn't help, the problem is in the washing machine.
The power filter in the machine, which evens out power surges during operation, has burned out. The filter can be replaced.
The power button closes. When pressed, a short circuit occurs and the machine turns off. Needs renovation.
The CM module (control board) is shorted. For example, the German brand Bosch is not designed for constantly unstable voltage in the network - electronics often fail. Need professional help.

We have listed the reasons why the machine knocks out at startup.

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 .

If a machine cracks, why is it dangerous?

You probably already guess that the crackling sound is the sound of sparking inside the case. Most often, its main cause is weakened contact of current-carrying elements.

In most cases, cracking occurs due to breakdowns inside or insufficient tightening of the wires in the terminals. Because of this, the insulation of the wires often catches fire, and the melting transfers to the flammable plastic housing.

Read: Laying the antenna cable

If you hear crackling noises, replace them quickly. Do not delay, because there is a very high probability of a fire. Moreover, the shield often becomes the source of fire in an apartment.

The sparks gradually melt the plastic case, causing it to begin to smoke and ignite. Due to deformations, opposite contacts may come into contact, causing a short circuit and causing all the wiring to burn.

Cracking is the first sign of danger, and in this case the machine must be replaced.

In rare cases, a reinstallation will be sufficient. For example, if the terminals were cracking due to loose tightening, then the machine must be dismantled and reinstalled. After this, watch him carefully. If the cracking still occurs, replace it with a new one.

In addition to cracking, users often perceive case heating as a problem. But this does not always indicate a malfunction.

Circuit breaker hums

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.

The only thing that can hum here is the trip coil or the electric magnetic release, which is triggered by short circuits.

Its core is constantly in a magnetic field, and if it is not tightened enough, it will actually make a similar sound. Under the influence of an electric magnetic field, the coil enters resonance and begins to vibrate.

Some people notice that when other devices are turned on, the sound disappears. But the point here is not in the device, but in the change in load and induction density. Following it, the vibration amplitude changes, and therefore the hum.

Although in exceptional cases, certain types of devices can actually have a similar effect on the machine and make it buzz.

For example, this may be caused by connecting consumers with a pulsed load to the network. Such as power supplies for computers or LED strips.

Turn off the fancy LED backlight and the noise disappears.

You cannot fix this, because some machines initially perceive such a load normally and operate without extraneous noise. Or at least you don't hear them.

And others will get on your nerves and hum like a transformer.

Therefore, we repeat once again, if the machine is buzzing, change it to another one.

Don't blame the electricians for this, they have nothing to do with it. You just received a defective product.

This could be a manufacturing defect, unknown transportation conditions (drops or impacts on the case), improper storage (in damp rooms), possible counterfeiting, and much more.

Therefore, even if you buy well-known brands (ABB, Hager, Schneider, Legrand), and not cheap IEK or TDM, you can still run into trouble.

Only pre-installation tests and loading the machines with a long-term primary current can save you from this. But 99.9% of users never do this.

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.

If you notice that the heating level is noticeably higher than +70°C, and light traces of melting are visible on the body or the handle is stuck, then this is an emergency. In such a situation, it is better to replace the machine with a new one. If you ignore it, at best the shield will burn out, at worst there will be a fire in the apartment.

If any of the problems occur, replace the machine. Don't take risks and don't try to repair it.

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.