Correct replacement of circuit breakers in the panel

Reasons for replacing machines

There are two main reasons:

1. Frequent activation of thermal protection.
2. Constant work at the limit.

It happens that even after the first operation of the thermal protection system, the machine stops working. However, outwardly this breakdown is impossible to notice. It is important to know that electromagnetic and thermal releases are not the same thing. Most often, breakdowns occur due to burning, and subsequently, the complete combustion of contact clamps, as well as the cases of modular devices themselves. This occurs mainly through unreliable and poor-quality contact. If the wiring is made with an aluminum wire, then at the connection points, the core will be weakened over time. Aluminum, softer metal and contact compounds with an aluminum wire weaken with time, aluminum “floats”. In order to avoid negative consequences, it is necessary to tighten the terminals of the machines once every 2-3 years.

Another reason is factory defects, but this is extremely rare. To avoid marriage, you should not save, and choose machines of well-known brands. ABOUT top circuit breaker manufacturers We told in a separate publication. You should be careful, because during installation this marriage does not make itself felt, but at the load it will certainly manifest itself. Regardless of the reason why the device has stopped working, you should immediately replace the machine, otherwise malfunctions can lead to fire wiring.

Also, the need to replace protective devices arises if there are old plugs, and not new circuit breakers. About, how to replace traffic jams with automatic machinesWe also talked in detail!

Replacement technology

Removing an old circuit breaker

Repair or restoration of such devices is not carried out. The reason for this is a rather complicated scheme, and at the same time, buying new machines will cost inexpensively. Basically, if this unit breaks down, it is simply replaced with a new one with similar characteristics, that is, with the same rating, class, breaking capacity.

Before dismantling the machine, it is necessary to completely disconnect the line that supplies the replaced device from the mains.Sometimes replacement is carried out under voltage, but in such cases only a specialist should replace it. If the work is carried out without turning off the electricity, then you should be very careful and careful, especially if the case is in very poor condition, as in the photo below.

Typically, the clamping plates are welded together, which makes it impossible to loosen the clamping screw. To carry out dismantling in such a difficult situation, it is necessary to have certain skills and experience. To simplify the task, you should initially leave a supply of wires in the shield.

If the wire connected to the machine is melted, the machine is burned, then when a new machine is installed, the charred, melted part of the wire must be completely removed and only a clean, stripped wire must be connected to the new machine - this is the only way to be sure of reliability. That is, in any case, there should be a margin. If there was no supply and it was necessary to connect a charred wire, especially aluminum as in the photo, then it is highly likely that the contact of the machine will burn again, since the core that was overheated no longer has the same load capacity and can be more fragile than a whole wire .

Most of the circuit breakers in the switchboard are responsible only for some separate line, which supplies, for example, sockets or lighting of a residential building. Therefore, it is very simple to de-energize such an automatic machine - you need to turn off the opening bag, which is usually located on the staircase in the stairwell.

However, it may be necessary to replace the circuit breaker, which is located in front of the meter, it is also called the opening machine. An introductory device, if it is in Khrushchev or a multi-storey panel building, is also located on the stairs in the electrical panel. In private homes, such a device can be on 380V, it is also called a three-pole machine. Replacement of such a circuit breaker is carried out by a specialist, as introductory machines in the shield are sealed, and for the failure of the seal faces a considerable fine.

After turning off the power, you need to check with the indicator and make sure that the power is completely turned off. Next, select the necessary screwdriver and loosen the clamp screw. After disconnecting, the wires should be pushed to the sides.

In the new panels, circuit breakers are mounted on DIN rail. If you do the dismantling in such a shield, it is much easier. At the bottom of the device there is a hole in which a screwdriver is inserted and pulled down. After removing the lower latch, tighten the bottom of the machine.

However, in many houses there are old-style circuit breakers that are not mounted on a rail, but are secured with a long screw. It is very difficult to remove a device in which these screws are rusted or attached.

Installing a new protection device

The first thing to do to replace the machine in the shield is to insert a new circuit breaker in place of the previous one. The process is as follows: we put the latch of the upper part of the device on the rail and slide the lower part until it stops and clicks. The next step is working with wires. If necessary, they need to be cleaned, then inserted into the clamping holes and tighten the screw. You should always pay attention to the condition of the connected wires and if there are signs of fusion, burning of the core, severe deformation of the core, then this section must be removed and the wire for connection to be re-stripped.

The performance of circuit breakers is checked by special equipment by loading them - checking the time-current characteristics. Without special equipment, it simply cannot be determined that a thermal or electromagnetic release does not work or does not work in accordance with the declared characteristics.And it turns out that a malfunction of an automaton can be detected only when it does not work, when necessary - that is, it will be possible to find out about its malfunction only by the consequences of an overload or short circuit (the automaton itself, the wiring or the socket will be damaged). That is, you can buy a new machine with a marriage, put it on, it can stand for 10 years, and a person will not suspect about its malfunction until there is an emergency in the wiring - overload or short circuit.

Also, you should be aware that the machine of any manufacturer can be factory defective. At enterprises, when they order dozens of machines for a new switchboard, they are always checked (loaded) before installation, since very often there will be a marriage of products, even of the best brands.

In everyday life, no checks are made, therefore, a redundant protective device must always be installed, installed on the input, which will de-energize the damaged section of the wiring in case of failure of one of the circuit breakers. And it is better for reliability to have an additional introductory machine in the home panel, since the machine that is standing with the meter in the entrance or on the support is located further away and, accordingly, it is less sensitive to increasing current. Also, if the machine at the input in front of the counter is installed outdoors, then its time-current characteristic changes with temperature. For example, the lower the ambient temperature, the greater the current and the trip time of the thermal release, that is, if one of the machines fails in the home panel, the wiring will be damaged before this machine works.

Important! When replacing a machine with a more powerful one, you need to be sure that this change does not negatively affect the wiring diagram. Nevertheless, if such a replacement is necessary, then you should consult with a specialist.

The video clearly shows how to replace the old circuit breakers in the switchboard with new ones:

At whose expense are the work performed

If the device malfunctions, the owners may have questions: who should change the machines in the shield, a replacement is paid for or free of charge. So, if we are talking about the input device, which is located in front of the meter, then it is a common house property, so the company must purchase and replace it for the money that the owners pay every month.

However, it is also important to know at whose expense the rest of the protective equipment is replaced. Everything that is behind the counter is the property of the owner of this housing, respectively, you must buy and replace yourself. Of course, you can replace the circuit breaker with your own hands, but it is better if a specialist does this.

That's all I wanted to tell you about how to replace the machine in the shield with your own hands. We hope our step-by-step instruction was useful for you and helped to understand the whole essence of the replacement!

We also recommend reading:

• How to replace wiring in an apartment
• What to do if an electric meter burns out
• Who should pay for the replacement of the electric meter