Main selection criteria

So, we will consider how to choose the most important parameters of the device for protecting wiring in a house and apartment.

1. Short circuit current. To select a short circuit breaker, an important condition must be observed – according to the PUE rules, it is prohibited to use machines with a higher breaking capacity of less than 6 kA. Today, devices can have ratings of 3; 4,5; 6 and 10 kA. If your house is located next to a transformer substation, you need to choose a circuit breaker that operates at the short-circuit limit of 10 kA. In other cases, it is enough to choose a switching device with a nominal value of 6000 Amer.
2. Current rating (working). The next, no less important criterion when choosing a machine for the home is its current rating. This characteristic displays the value of the current that the above circuit will disconnect and, thus, protects the wiring from overloads. In order to choose a suitable value (it can be 10, 16, 32, 40 A, etc.), it is necessary to rely on the cross-section of the household wiring cable and the power of electricity consumers. It is about how much current the wires can pass through them and at the same time, what is the total power of all household appliances, the operating current of the switching device will depend. In this case, to select the appropriate circuit breaker characteristic, we recommend first determining the cable cross-section in your house or apartment, and then be guided by these tables:

   

   

   

3. Starting current. Simultaneously with the operating current of the device, it is necessary to determine its rating according to the operating current. As you know, when operating powerful electrical appliances, the starting current can be much higher than the rated current (up to 12 times). So that the circuit breaker does not operate, perceiving the inclusion of the motor as a short circuit, you must correctly determine the class of the switching device.Today, classes B, C and D can be used. For domestic use, for a house and apartment it is better to choose a class B device if the kitchen has On a gas stove and there are no powerful consumers of electricity. If a powerful electric stove or electric boiler is installed, it is better to choose a suitable automatic machine of class C. Well, if you have high-power motors in your private house, you need to select a switching device marked “D”.
4. Selectivity. This term means emergency shutdown of only a specific problem area, not all of the electricity in the home. Here it is already necessary to penetrate a little into the logical chain and determine the ratings of circuit breakers according to the service line. The upper part of the so-called branch should be occupied by an automatic inserting machine, the rating of which should not exceed the maximum permissible load on the wires, based on the cross-section of the wire. The rated current of the input switching device must exceed the operating current value of all other circuit breakers in the panel. For a private house, it is recommended to choose a device for 40 A for input, 32 A for an electric stove, 25 A for electrical appliances up to 5 kW, 16 A for sockets and 10 A for lighting. When choosing this option switchboard assembly the selectivity condition will be met.
5. Number of columns. Another no less important selection criterion, about which, as a rule, the least questions arise. Therefore, for a single-phase 220 V network, it is recommended to choose a double-pole single-phase circuit breaker for the input. For separately connected lighting and household appliances (for example, washing machine, water heater, air conditioning), you need to choose a suitable single-pole circuit breaker. If you have a three-phase power supply in your home, purchase a four-pole input transformer. Well, to protect the motor from overcurrents, you need to choose a three-pole circuit breaker for 380V.
6. Factory factory. It is very important to choose the right company for the device, otherwise when buying a fake, it is far from the fact that the above parameters are the same in reality. As a result, with a short circuit current, the electromagnetic release may not work and, as a result, a fire in the house.

We also recommend watching the video instructions, which provides all the necessary tables and formulas for choosing a circuit breaker of current, current and electrical cross-section:

The listed criteria for choosing a circuit breaker are basic, and above all pay attention to these parameters. It should be noted that saving on machines is very stupid! The difference between a quality product (from the manufacturer ABB or Schneider Electric) and a fake is not so big, considering that your home and, most importantly, life are at stake!

Invalid purchase errors

There are many mistakes that beginners can make when choosing a circuit breaker in terms of current and load. If you choose the protective automatic incorrectly, even if you miss a little of the nominal, this can lead to many negative consequences: the machine trips when the device is turned on, the electrical wires will not withstand current loads, the service life of the circuit breaker will quickly decrease, etc.

To prevent this from happening, we recommend that you familiarize yourself with the following errors, which will allow you to choose the right circuit breaker for your future home or apartment:

• The first and most important thing you should know is that during the conclusion of the contract, new subscribers request the power capacity of their connection. From this, the technical department calculates and determines where to make the connection and whether the equipment, lines and TP can withstand the load. Also, according to the declared power, the cable cross-section and the circuit breaker rating are calculated. It is unacceptable for apartment subscribers to arbitrarily increase the load on the input without upgrading it, because the project has already announced the power and laying of the power cable. In general, the value of the introductory device is not chosen by you, but by the technical department. If in the end you want to choose a stronger circuit breaker, everything must be coordinated.
• Always focus not on the power of household appliances, but on the wiring. A machine should be selected only according to the characteristics of electrical appliances, if the wiring is old. The danger is that, for example, if you choose a 32A model to protect an electric stove, and the cross-section of an old aluminum cable can withstand only a current of 10 A, then your wires will not withstand and will quickly melt, which will cause a short circuit in the network. If you need to choose a powerful switching device for protection, first of all replace the wiring in the apartment to a new, more powerful one.
• If, for example, when calculating the appropriate rating of the device according to the operating current, you have an average value between two qualities – 13.9 A (not 10 and not 16 A), then give preference to a larger value only if you know that the wires will withstand the load current at 16A.
• For a summer residence and a garage, it is better to choose a more powerful circuit breaker, because a welding machine, a powerful submersible pump, an induction motor, etc. can be used. It is better to provide a connection for powerful consumers in advance, so that you do not overpay by purchasing a larger switch device. As a rule, 40A is sufficient to protect the line in domestic use conditions.
• It is advisable to pick up all automation from one high-quality manufacturer. In this case, the probability of non-compliance is reduced.
• Buy goods only in specialized stores, and even better – from an authorized distributor. In this case, you are unlikely to choose a fake, in addition, the cost of products from a direct supplier is usually slightly lower than from intermediaries.

That’s the whole technology for choosing the right machine for your home, apartment and cottage! We hope that now you know how to choose a circuit breaker in terms of current, load and other equally important characteristics, as well as what mistakes should not be made when buying!