How to choose a circuit breaker for home, apartment

Before choosing a circuit breaker, let's try to figure out what it is and what it is for. So, the circuit breaker is designed primarily to protect the supply lines, that is, the wires, from overload, short circuit.

Most often, to protect the home electrical network, we use machines of the VA series. VA series machines have two types of protection: thermal and electromagnetic. Almost all modern automatic devices are arranged in almost the same way: an arcing chamber, a magnetic release and a bimetallic plate, a contact group, a lever mechanism, etc.

Thermal protection is a bimetal plate. If the current that flows through the plate exceeds the nominal current, the plate heats up, bending occurs, then this same plate pushes a special lever, the machine turns off.

Electromagnetic protection is designed to protect the circuit from short circuits, or, as it is called correctly, against overcurrents that result from short circuit (KZ). During a short circuit, an electromagnet is triggered, which activates a trip mechanism. This is how the circuit breaker works.

A correctly selected circuit breaker (circuit breaker) will work in time and disconnect damaged, wiring, equipment from the mains, thereby preventing the ignition of the wiring. How to choose the right machine? What should I look for when choosing?

First of all, when choosing an automatic machine, the cross-section of wires and the load on the line should be taken into account. When choosing a machine, take an interest in its origin, ask the seller for product documents, certificates. Although, to be honest, the availability of documents is not always a guarantee of quality.

It is better to buy machines in specialized stores or from authorized dealers. Firms supplying such equipment to our market value their reputation and, as a rule, do not sell products of poor quality. True, the price of machines in such stores is an order of magnitude higher than in the markets.

It is worth giving preference to well-known brands of machines, if they are faked, then fake is of relatively normal quality. When completing the shield, it is necessary to take into account selectivity, that is, go from larger to smaller. For example, if an automatic machine with a face value of 40A is standing at the input, it is necessary to install a machine in 20A, lighting-10A on sockets. And do not forget about the cross-section of wires and the rated load.

Choosing an automatic machine with the parameters we need is easier than you think. To do this, remember the physics lessons from the school curriculum. There is such Ohm's universal law. I = P / U, Here, according to this very law, we will try to choose an automaton of the desired nominal value.

So, you roughly know the power, the voltage in the network is also 220V. For example, on the kitchen you will have devices with a total power of 3 kW-3000 W, divide this amount by voltage-220 V, get the number 13.6 A. The nearest machine at par -16 A. Here it is and put it, provided that you have copper wiring and the cross section of these same wires is not less than 2.5 mm square. Everything must be calculated and counted.

Automatic machines, depending on the manufacturer, are designed for a certain number of operations. So, using them too often to turn on / off the load is not recommended. Firstly, the mechanism wears out and, secondly, the contacts burn out, which leads to heating of the contact group, and as a result to its failure. For frequent switching of the load, use devices specially designed for this purpose - relays or magnetic starters (contactors).

The cases of circuit breakers of various manufacturers often differ from each other, both in the seat on the DIN rail and in the place where the conductor is attached to the machine. So, when buying or changing a failed machine, choose a machine of the same manufacturer as in the dashboard. In any case, all work related to electricity, trust only professionals, otherwise troubles can not be avoided.

Read more about this here:How to choose a circuit breaker for an apartment, house, garage