16A circuit breaker - what load can it withstand?

The existence of modern man is no longer possible without electricity. Each house, apartment, and production facility is equipped with different equipment. Rarely do property owners think about how much electricity is consumed in total - calculations are made only during the initial installation of electrical wiring. But if the network voltage is exceeded, a short circuit will occur and the network will fail. To prevent such situations, a circuit breaker is used. For domestic needs this is a 16 amp machine.

What is important to know when connecting electrical appliances

So, having calculated the approximate rating of the required machine, you need to give an explanation regarding the power. Many people wonder whether it is possible to plug in very powerful electrical appliances into a regular outlet, such as an electric boiler, for example.

According to the rules of the PUE, connecting an electric boiler with a power of more than 3 kW to a regular outlet is unacceptable. And each outlet has its own specific characteristics. Most often, home sockets are rated at 16 amperes, and, therefore, electrical appliances with a power of no more than 3.5 kW can be connected to them.

Therefore, any more or less powerful electrical appliance must be connected only through a separate circuit breaker. Moreover, it is the phase wire that is supplied to the circuit breaker, and not the working zero. Thus, knowing the approximate power of the equipment, you can easily calculate the rating of the circuit breaker.

Machine connection diagram

On the front side of the 16 Amp circuit breaker you can see the wiring diagram. This is not necessary, but for a novice electrician this marking shows the number of poles, connection points of the supply and transmission phases, and the neutral wire.

So, using clamping plates and screws, a suitable contact is fixed in the upper part of the device, and an outgoing one in the lower part. The neutral wire is connected in the location specified by the manufacturer (N). For grounding, a terminal separate from the machine is installed in the panel.

Knowing what is hidden under the marking of the circuit breaker, you can make the right choice yourself. This applies to both the device itself and the wires (material, cross-section). Information about the connection diagram will allow you to install the device yourself.

How to choose a current circuit breaker?

On the front side of the circuit breaker housing, manufacturers indicate important and at the same time incomprehensible designations for the average person. In the photo below, I specially circled it with a red frame; the designation indicates the rated current of the machine, which is measured in amperes

This is the most important parameter that you need to pay attention to first.

The letter located to the left of the rated current indicates the multiple of the EmR cut-off current (Iotc) in relation to the rated current of the machine. That is, in simple terms, when a short circuit current occurs, the EmR indicates the time of instantaneous operation of the machine. These letters are different, the most popular are the letters “B” Iots = 3...5In, “C” Iots = 5...10In, and “D” Iots = 10...20In.

Machines with the letter "B". They are mainly used in old residential buildings in which the electrical wiring has not been reconstructed. They are often used in country and rural houses that receive power from overhead lines that are very long.

I would also like to draw your attention to the fact that the price of such machines with the letter “B” is slightly higher than with the letter “C” and they are not on sale, only on order

Slot machines with the letter "C". They are the most common and commercially available. They can be used in electrical networks that are in satisfactory (good) condition.

Machines with the letter "D". Due to the high cut-off current ratio (10...20In), such machines are used in industry to protect lines that have large starting currents, which arise, for example, when starting powerful electric motors. Therefore, they have no place in residential buildings!

So, we figured out the letter, now we move on. Before choosing an automatic circuit breaker, you need to take into account the cross-section of the wires, that is, the cross-section of the electrical wiring cable that is located in your house or apartment.

Adhere to the following ratios:

Calculation of the machine according to the cross-section of the electrical wiring.

If the cross-section of the copper core is 1.5 mm square (aluminum 2.5), select the rating of the machine 10A, area of ​​use, lighting.

If the cross-section of the copper core is 2.5 mm square (aluminum 4.0), select the rating of the machine 16A, area of ​​use, sockets.

If the cross-section of the copper core is 4 mm square (aluminum 6.0), we select the rating of the machine 25A, area of ​​use, water heaters up to 5 kW.

If the cross-section of the copper core is 6 mm square (aluminum 10), we select the rating of the machine 32A, area of ​​use, water heaters more than 5 kW, electric stoves.

If the cross-section of the copper core is 10 mm square (aluminum 16), we select the rating of the machine 50A, area of ​​use, entry into apartments with electric stoves.

Features of switches

Circuit breakers are made of materials that are completely harmless to human health. Self-extinguishing thermoplastic is used in the manufacture of the device body. It is able to withstand very high temperatures. Its contacts are made of copper plates, silver plated for better contact and durability.

The design of the circuit breaker contains a special thermal relay, which is activated when the current flow exceeds the norm, and the electrical circuit opens without causing a short circuit. The higher the current indicator, the faster the operation speed of the machine. The count goes on in fractions of a second.

The scope of use of automatic switches is very extensive and extends from their installation in incoming electrical panels to distribution boards of apartments or houses. To use circuit breakers, special distribution boards are produced with already installed DIN rails for the required number of circuit breakers. The buyer only needs to choose the one that meets his wishes and install the shield in the apartment or house.

Despite the apparent simplicity of using circuit breakers, it is better to entrust the connection of a 16-amp circuit breaker to a specialist.

In terms of rated current, circuit breakers differ both in current strength (rated from 1A to 6300A) and in the load on the circuit (220V, 380 and 400V). In addition, switches are usually distinguished by their response speed.

Characteristics of a 16 amp machine

It is marked on its body with rated current, switching capacity, current limiting class, rated breaking capacity and time-current response characteristics of the switching system. The rated current value is 16 amperes, which can be lowered or increased when the temperature changes in the appropriate direction. The switching capacity is 4500 and 6000 amperes for a household unit, and the current limit is 10 milliseconds.

Technical characteristics of the circuit breaker

Unacceptable mistakes when purchasing

The most common mistakes when choosing and purchasing an input circuit breaker are ignorance of the principles of its operation and choosing a machine rating lower or higher than the required value. If you choose a machine with a lower rating, then it is possible that the protection will trigger falsely and shut down the entire apartment due to one device. If you select a rating higher than the required value, it may work after the wire insulation or devices inside the electrical panel overheat and begin to melt or burn.

There are also “professionals” who connect two single-pole circuit breakers instead of a two-terminal circuit, not knowing that this violates electrical safety requirements and the PUE prohibits such a connection.

If you have doubts about the selection and installation of such a device, you should contact a professional electrician and rest assured that the correct choice and safe installation.

Purpose of circuit breakers

In order to prevent such a situation, there are automatic switches. The most common and well-proven ones are ABB switches. A 16 amp machine is usually installed indoors. Such switches are produced in the form of modules, due to which they can be freely mounted in the required quantity and in the right place.

It is best to use special DIN rails designed for mounting switches on them. Anyone, even someone who is not very knowledgeable about electrical engineering, can install such switches. The only thing you need is to choose the correct rating of the device you are using.

Among other things, circuit breakers can, if necessary, be supplemented with various remote shutdown sensors, operation indicators, etc., which will ultimately make the use of the electrical installation more comfortable and durable.

When the electricity suddenly turns off in a house or apartment, they begin to look for the cause. And it often lies in exceeding the permissible load on the network. In other words, many more electrical appliances are connected to the sockets than were calculated during construction, or than were allocated for a specific consumer.

So how can you determine what load the machine will withstand at the entrance to a house or apartment, or at a separate consumption group? There are a few simple rules, and if you follow them, problems with power outages should not arise

And it doesn’t matter which machine is used - 16 amperes or 25, etc.

Purpose

A 25 ampere circuit breaker is a device whose main task is to ensure the safety of the electrical network from overcurrent, that is, from a short circuit with overload. The main purpose of the device is to ensure the safety of the user himself when using the network and electrical appliances.

Such equipment is turned on and off from an electrical circuit. It is most often used to protect an electric stove or other kitchen heating appliances.

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Note! It can also be used to protect lighting system, motor, transformer and electronic appliance.

Electrical circuit protection as the main purpose

General characteristics and markings of C32 circuit breakers

Single-pole circuit breaker C32

Many characteristics of the switch are indicated on its body. The main one is the rated current. This is the maximum current that the device passes in normal mode and for a long time. For the C32 machine it is 32 Amperes.

Another important characteristic is the ability of the protective device to turn off short-circuit currents of a certain value (switching capacity). After activation, the device must remain fully operational. The short circuit current is usually indicated in a rectangular box. For a 32 Ampere machine it is 4500 A, or 6500 A.

Industrial devices use additional characteristics:

• ultimate breaking capacity Icu – double operation current that does not damage the device;
• operating breaking capacity Ics – triple tripping current.

The higher the breaking capacity, the more reliable and durable the device.

In the process of disconnecting a short circuit, an electric arc flashes between the contacts of the switch. It has a high temperature and can destroy the device. Extinguishes using arc chutes. The faster this happens, the higher the current limiting class of the device:

• for first class – above 10 milliseconds;
• for the second – less than 10 milliseconds;
• for third grade – from 3 to 6 milliseconds.

This characteristic is marked with the numbers 2 or 3 in a square frame. If there is no such marking, it is a 1st class machine gun.

In any machine there are two automatic shut-off elements.

• Electromagnetic release. Designed to trigger when short circuit currents occur. Operated by a current relay.
• Thermal release. Triggers when heated due to overload of the protected area. Based on the operation of a bimetallic contact.

Time-current characteristics are calculated for each separately. They are designated by Latin letters A, B, C, D and are indicated together with the rated current. For the C32 assault rifle this is characteristic “C”.

In order to protect against overload currents, the thermal release is adjusted to certain values. For circuit breaker C32, the time-current characteristic is 1.13-1.45 of the rated current. This means that a device with a rating of 32 Amperes will turn off in an hour at a current of 1.13 × 32A = 36.2 Amperes. If 1.45×32=46 Amperes flow, it will turn off in less than an hour. As the overload increases, the tripping speed will decrease until the electromagnetic release starts to operate.

Marking

The average person pays attention only to the brand name and amperage, which the manufacturer applies to the body using laser technology or indelible paint. For professionals, all indicators are important. Depending on the machine, the number of characteristics may vary.

Marking

This is what is hidden under the numbers and letters on the front side:

• ABB, IEK, Legrand - manufacturer's logo.
• S, SH, Acti, Easy, BM, TX - linear series of modular products. The letter may be followed by various numbers.
• 6, 10, 16 and more - the maximum current value at which the circuit does not open. It is worth noting that the indicator is relevant at a temperature of +30 degrees Celsius. The product is triggered by an overload of 13-55%. If it is colder, the machine will turn off at a higher load, and vice versa in the heat.
• 230V, 400V - network voltage (single-phase or three-phase) at which use is allowed.
• 4500, 6000 or 10000 is the limit (switching capacity) at which tripping occurs during a short circuit. In this case, the device does not fail. If a short circuit occurs with a value exceeding the value, the magnetic release will not cope with it and the device will burn out. The indicator is enclosed in a rectangle.

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Short circuit limits

• 1, 2 or 3 next to the short circuit - an indicator of the speed of extinguishing the electric arc (from 10 ms, from 6 ms and from 2.5 ms, respectively). During a short circuit, the conductors heat up, which affects the insulation. The faster the machine works, the more intact the wiring and the device itself will be. The first class is usually not indicated.
• B, C, D, K, Z before amperage - time for automatic shutdown of the device in the event of a short circuit or overload in the network. In everyday life, products with characteristics of type C are more often used, less often B and D. For example, C16 will turn off at 80-160A, and B16 at 46-80A. That is, the second one will work later. The difference is in fractions of a second.
• Wave or straight line - can be used in AC or DC voltage networks. These marks are located next to the rated voltage.

Voltage

• 50/60 Hz - frequency of oscillations in the network. The indicator is not always indicated, since most household appliances operate in one mode.
• Connection diagram. 1, 3, 5 and 2, 4, 6 - upper (supply) and lower (loaded) contacts. N - pole for connecting the neutral core.

On the side plane it is indicated:

• GOST or IEC/EN - compliance with standards (Russian or international).
• U is the operating voltage.
• Icn is the maximum breaking capacity value.
• I—electromagnetic shutdown limit.
• Uimp is the impulse withholding voltage.
• Ui is the insulation voltage.
• Deg is the degree of pollution, which depends on moisture condensation.
• Cat - application category regarding selectivity.
• Barcode or QR code is information about a product that, when read by a special device, is obtained on the trading platform.

Bar code
In addition, the manufacturer indicates the tightening torque, number of poles, and type of release. Differential machines have additional markings.

Description of the main parameters

The rated current of any (including double) 25 Ampere machine is indicated in its marking. It means the value at which the device operates for a long time without turning off. This parameter is entered taking into account the average air temperature of 30°C. If it decreases, it will increase, and if it increases, on the contrary, it will decrease.

The switching capacity of a circuit breaker characterizes its ability to instantly switch off at short-circuit currents of a certain magnitude. This indicator for household appliances takes typical values ​​of 4.5 thousand or 6 thousand Amperes. In industrial designs it is indicated separately (without a square frame). The higher the switching capacity of the model, the higher quality the machine is considered and the more expensive it is.

The current limit class indicates how long it takes to extinguish an arc that occurs when switching high currents. There are 3 known classes of switches that differ in this parameter:

• In the third class, the arc goes out in 3-5 milliseconds.
• In devices of the second group, it takes 5-10 milliseconds to extinguish it.
• For devices of the first class, the restriction is not standardized. The process usually occurs in 10 milliseconds or more.

In any machine, two releases are used as actuating elements. One of them (thermal type) is made as a bimetallic plate, and the other is electromagnetic, which is an overcurrent relay. The first switches off the device when the current power is exceeded for a long time on the section of the line protected with its help. The electromagnetic release is triggered when there is a short circuit in the circuit. The current values ​​at which the circuit breaker turns off, as well as time delays, are called its time-current characteristics.

Trip characteristics of protective circuit breakers

Class AB, determined by this parameter, is indicated by a Latin letter and is marked on the body of the machine before the number corresponding to the rated current.
In accordance with the classification established by the PUE, circuit breakers are divided into several categories.

MA type machines

A distinctive feature of such devices is the absence of a thermal release. Devices of this class are installed in circuits connecting electric motors and other powerful units.

Class A devices

Type A machines, as was said, have the highest sensitivity. The thermal release in devices with time-current characteristic A most often trips when the current exceeds the nominal value AB by 30%.

The electromagnetic trip coil de-energizes the network for approximately 0.05 seconds if the electric current in the circuit exceeds the rated current by 100%. If for any reason, after doubling the electron flow, the electromagnetic solenoid does not work, the bimetallic release turns off the power within 20 - 30 seconds.

Automatic machines with time-current characteristic A are connected to lines during operation of which even short-term overloads are unacceptable. These include circuits with semiconductor elements included in them.

Class B protective devices

Devices of category B are less sensitive than those of type A. The electromagnetic release in them is triggered when the rated current is exceeded by 200%, and the response time is 0.015 seconds. Triggering of a bimetallic plate in a breaker with characteristic B at a similar excess of the AB rating takes 4-5 seconds.

Equipment of this type is intended for installation in lines that include sockets, lighting devices and other circuits where there is no starting increase in electric current or is of minimal value.

Category C machines

Type C devices are the most common in household networks. Their overload capacity is even higher than those previously described. In order for the electromagnetic release solenoid installed in such a device to operate, it is necessary that the flow of electrons passing through it exceeds the nominal value by 5 times. When the thermal release is exceeded five times the nominal value of the protection device, the thermal release is triggered within 1.5 seconds.

Installation of circuit breakers with time-current characteristic C, as we said, is usually carried out in household networks. They do an excellent job as input devices to protect the general network, while category B devices are well suited for individual branches to which groups of sockets and lighting fixtures are connected.

Circuit breakers category D

These devices have the highest overload capacity. To trigger the electromagnetic coil installed in a device of this type, it is necessary that the electric current rating of the circuit breaker be exceeded by at least 10 times.

In this case, the thermal release is activated after 0.4 seconds.

Devices with characteristic D are most often used in general networks of buildings and structures, where they play a backup role. They are triggered if there is no timely power outage by circuit breakers in individual rooms. They are also installed in circuits with large starting currents, to which, for example, electric motors are connected.

Protective devices categories K and Z

These types of machines are much less common than those described above. Type K devices have a large variation in the current required for electromagnetic tripping. So, for an alternating current circuit this indicator should exceed the nominal value by 12 times, and for a direct current circuit - by 18. The electromagnetic solenoid operates in no more than 0.02 seconds. Triggering of the thermal release in such equipment can occur when the rated current is exceeded by only 5%.

These features determine the use of type K devices in circuits with exclusively inductive loads.

Devices of type Z also have different actuation currents of the electromagnetic tripping solenoid, but the spread is not as great as in AB category K. In AC circuits, to turn them off, the current rating must be exceeded three times, and in DC networks, the value of the electric current must be in 4.5 times more than nominal.

Devices with Z characteristic are used only in lines to which electronic devices are connected.

Visually about the categories of machines in the video:

How to calculate a circuit breaker. Automatic 25 amperes how many kilowatts

Selecting a machine based on load power and wire cross-section

1. Selecting a machine based on load power
2. Selecting a machine according to cable cross-section
3. Selecting a circuit breaker based on short-circuit current
4. Selecting a machine based on the long-term permissible current of the conductor
5. Example of machine selection
6. Summary table for selecting a circuit breaker for a two-phase 220 V network
7. Summary table for selecting a circuit breaker for a three-phase 380 V network.
8. Results

Selecting a machine based on load power

To select a circuit breaker based on load power, it is necessary to calculate the load current and select the rating of the circuit breaker greater than or equal to the obtained value. The current value expressed in amperes in a single-phase 220 V network usually exceeds the load power value expressed in kilowatts by 5 times, i.e. if the power of the electrical receiver (washing machine, light bulb, refrigerator) is 1.2 kW, then the current that will flow in the wire or cable is 2.4 A (1.2 kW * 5 = 6.0 A). Calculated at 380 V, in three-phase networks, everything is similar, only the current value exceeds the load power by 2 times.

You can calculate more accurately and calculate the current according to Ohm's law I=P/U - I=1200 W/220V =5.45A. For three phases the voltage will be 380V. You can

Machine capacity and power indicator

In response to the question, 16 amperes are how many kilowatts, it is worth pointing out that such a circuit breaker can withstand a load of 3.5 kW in a single-phase network and 18.2 kW in a three-phase network. A 32A device is 7 and 36.5 kW, a 40A device is 8.8 and 45.6 kW, a 63A device is 13.9 and 71.8 kW, respectively. In this case, the supply voltage in the outlet in the first case should be no more than 220 volts, and in the second case - no more than 380 volts.

16 amp breaker

Power or load force is the amount of energy consumed by all electrical appliances that are connected to the same line. To calculate this number, you need to take the current load and select a higher current rating or equal to the resulting value.

Note! The power of the device 16A is 3520 W, 32A - 7040 W, 40A - 8800 W, 63A - 13860 W in a single-phase circuit. The power of the device 16A is 6080 W, 32A - 12160 W, 40A - 15200 W, 63A - 23940 W in a three-phase circuit. The conversion to kilowatts is presented above.

Table of amperes and kilowatts

Connection diagram

Connection diagram without grounding

According to the PUE, the supply conductor is connected to a fixed microcontact. This means connecting from above (there may be exceptions). You need to look at the connection diagram located on the device body. The designations are as follows:

• symbol 1 in the diagram shows where the input of the first phase conductor is connected;
• 2 – shows the output of the first phase conductor;
• 3 – entrance;
• 4 – output for a two-pole device;
• 5 – entrance;
• 6 – three-pole output;
• 7 – entrance;
• 8 – four-pole output.

If, in addition to the numbers on the diagram and contacts, there is a designation of the letter N, the neutral conductor is connected here. When there is no such symbol, zero is connected to the terminals indicated by the maximum numbers. If the phase conductors are connected from above, then so is the zero. If the phase conductors are connected from below, the neutral one is also connected from below.

Convert Watts (W) to Amps (A).

Converting amperes to kilowatts (single-phase 220V network)

For example, let's take a single-pole circuit breaker with a rated current of 16A. Those. A current of no more than 16A should flow through the machine. In order to determine the maximum possible power that the machine can withstand, you must use the formula: P = U*I

where: P – power, W (watt);

U – voltage, V (volt);

I – current strength, A (ampere).

We substitute known values ​​into the formula and get the following:

P = 220V*16A = 3520W

The power is obtained in watts. We convert the value into kilowatts, divide 3520W by 1000 and get 3.52kW (kilowatts). Those. the total power of all consumers that will be powered from a machine with a rating of 16A should not exceed 3.52 kW.

Converting kilowatts to amperes (single-phase 220V network)

The power of all consumers must be known:

Washing machine 2400 W, Split system 2.3 kW, microwave oven 750 W. Now we need to convert all the values ​​into one indicator, i.e. convert kW to watts. 1 kW = 1000 W, respectively, Split system 2.3 kW * 1000 = 2300 W. Let's sum up all the values:

2400 W+2300 W+750 W=5450 W

To find the current strength, power 5450W at a network voltage of 220V, we use the power formula P = U*I. Let's transform the formula and get:

I = P/U = 5450W/220V ≈ 24.77A

We see that the rated current of the selected machine must be no less than this value.

Converting amperes to kilowatts (three-phase network 380V)

To determine the power consumption in a three-phase network, the following formula is used:

P = √3*U*I

where: P – power, W (watt);

U – voltage, V (volt);

I – current strength, A (ampere);

It is necessary to determine the power that a three-phase circuit breaker with a rated current of 32A can withstand. We substitute the known values ​​into the formula and get:

P = √3*380V*32A ≈ 21061W

We convert watts to kilowatts by dividing 21061W by 1000 and find that the power is approximately 21kW. Those. a three-phase 32A circuit breaker can withstand a load of 21 kW

Converting kilowatts to amperes (three-phase 380V network)

The current of the machine is determined by the following expression:

I = P/(√3*U)

The power of a three-phase consumer is known, which is equal to 5 kW. The power in watts will be 5kW*1000 = 5000W. Determine the current strength:

I = 5000W/(√3*380) ≈ 7.6 A.

We see that for a consumer with a power of 5 kW, a 10 A circuit breaker is suitable.

A short guide to choosing the right differential machine

Most often, potential consumers are faced with a choice - what to buy, a differential circuit breaker or a residual current device. Several reasons influence the decision:

The design feature of the shield is that it has sufficient space. Here the advantage is on the side of the machine, since it is more compact. And the RCD implies the presence of protection provided by the machine, therefore, it is necessary to install two devices that take up a lot of space.

Purpose of connection. Differential circuit breakers are ideal for protecting household appliances from current. But the protection of several outlets is better provided by an RCD. When the power increases, the machine will be immediately deactivated. As for the RCD, in the case of it you will only need to replace the machine.

In any case, before purchasing, be sure to choose the model that best suits the parameters of your network. First, calculate the current strength. Sum up the power of all devices on a particular circuit, and then divide this sum by the network voltage.

Before purchasing a 16A differential circuit breaker, decide on a specific model that suits all the characteristics of your network. Count the number of amps. To do this, sum up the power of each device in a certain circuit and divide the result by the number of volts. This will help you understand whether this device is suitable for you.

Choosing the right machine

How can you understand how many kilowatts a 16-amp machine can withstand in practice?

The most common correct way to select a circuit breaker is:

• determine the wire cross-section
• according to the rules of electrical installations, find the current that is permissible for such a wire cross-section
• select the machine that suits these parameters

For example, there is a copper wire with a cross section of 1.5 sq. mm. The current allowed for it is a maximum of 18-19 amperes. Accordingly, according to the rules, you need to choose a suitable machine, but with a downward shift according to the table. And this turns out to be 16 amperes. That is, you can install a 16 amp machine.

If the wire is copper and its cross-section is 2.5 sq. mm, then only a current of up to 26-27 amperes is allowed. Therefore, the maximum you can use is a 25-amp machine. Although, for reasons of reliability, it is better to install a 20-amp machine.

In this way, the parameters of the required machine for the remaining wire sections are calculated.

Cable cross-section for machine s16

In residential buildings, as a rule, a single-phase network is used. Therefore, wiring is chosen with 2 or 3 cores. Their cross-sectional diameter must correspond to the installed 16-amp electric machine. The maximum permissible diameter is 25 square meters. mm, but the indicator also depends on the metal of which the cable is composed. Here is their comparative characteristics:

Metal in wires

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Terminals in socket

Despite the noticeable difference in the cost of materials (aluminum wiring is 2-3 times cheaper), most cables are laid using copper cable. When choosing the cross-section of the cores, they rely on the nature of the machine and the method of placing the wires.

For a 16A protective device, the copper core must have a cross-section of 2.5 square meters. mm. This corresponds to its maximum voltage of 21A in a walled position, 30A in an open position (it is in contact with the external environment, which means it easily gives off heat when heated).

If you take a wire with a cross section of 1.5 sq. mm, then within an hour it will overheat and fail. This is justified by the maximum permissible current of 18 A.

Installation inside and outside walls

Features of switches

Circuit breakers are made of materials that are completely harmless to human health. Self-extinguishing thermoplastic is used in the manufacture of the device body. It is able to withstand very high temperatures. Its contacts are made of copper plates, silver plated for better contact and durability.

The design of the circuit breaker contains a special thermal relay, which is activated when the current flow exceeds the norm, and the electrical circuit opens without causing a short circuit. The higher the current indicator, the faster the operation speed of the machine. The count goes on in fractions of a second.

The scope of use of automatic switches is very extensive and extends from their installation in incoming electrical panels to distribution boards of apartments or houses. To use circuit breakers, special distribution boards are produced with already installed DIN rails for the required number of circuit breakers. The buyer only needs to choose the one that meets his wishes and install the shield in the apartment or house.

Despite the apparent simplicity of using circuit breakers, it is better to entrust the connection of a 16-amp circuit breaker to a specialist.

In terms of rated current, circuit breakers differ both in current strength (rated from 1A to 6300A) and in the load on the circuit (220V, 380 and 400V). In addition, switches are usually distinguished by their response speed.

Manufacturers and brands

Single-pole circuit breaker ABB 1P C25

Before choosing and buying a C25 circuit breaker, you should familiarize yourself with the companies that represent them and the price. Well-known instrument manufacturers:

• The Swedish-Swiss company ABB is rightfully considered the leader in the market of electrical products of this class.
• Circuit breakers from Legrand (France) are not inferior in quality to the previous brand, and the prices are approximately comparable in value.
• The products of another French company (Schneider Electric) are well known to domestic consumers, who speak highly of this product.

The price of a C25 assault rifle on the domestic market ranges from 100 rubles. up to 100 thousand rubles depending on the number of poles, company and brand.

How many sockets can be connected to one 2.5 square wire?

It should be noted right away that according to GOST R 53315-2009 in residential premises (apartments and private houses) it is allowed to make electrical wiring for sockets using VVGngLS copper cable with a cross-section of each core of 2.5 mm.sq.

Quite often, in two and even three-room apartments, 15-20 sockets are installed on such a cable coming from the distribution panel, and this is normal. You can “hang” as many sockets on one cable as you like, because they are not consumers of electrical energy and do not create a load on the cable. Each socket (even if several mechanisms are connected by a cable) with a reliable connection is only a conductor (as well as a cable).

The main condition for safe operation of the cable is that the total power consumption of consumers (electrical appliances, devices) that will be turned on simultaneously does not exceed the threshold value for a given cable.

The GOST cable with a core cross-section of 2.5 square is designed for long-term current transmission of 25-27A, which is equal to the power of electrical devices of 5.5-5.9 kW. Exceeding these values ​​leads to heating of the conductor and, as a result, the possibility of a fire.

If you need to connect electrical appliances with a higher total power, it is recommended to divide the sockets into two or more lines. Each group is powered by a separate cable.

Today, with a large amount of electrical equipment, this principle is used in apartments and houses when designing and installing electrical wiring - separate lines are laid in the kitchen, bathrooms and living quarters (living room, bedroom, children's room...).

For energy-intensive electrical appliances, such as, for example, a boiler, washing machine, air conditioner, electric stove, oven... a separate line is laid and only one socket is installed or the device is connected directly to the electrical cable.

Each individual line or socket group must be protected by its own circuit breaker or circuit breaker.

Conclusion: an unlimited number of sockets can be connected to one cable with a cross-section of 2.5 square meters, provided that the total power of consumers connected to them will not exceed 5.5-5.9 kW. But as practice shows, it is better not to abuse maximum loads and leave 20% of the power reserve for the cable. This means that the maximum load on the cable will be 2.5 square – 4.4 – 4.7 kW.

How many kilowatts can a machine withstand 16, 25, 32 and 40 Amps?

Automatic switches are used to supply electricity to the house, as well as to individual electricity consumers. It is recommended to install separate circuit breakers for a group of sockets and lighting, as well as high-power electrical devices: electric boilers, heating elements, etc.

To choose the right machine, you need to refer to the cross-section of the conductor that will be connected to it. The conductor itself must be selected taking into account the power consumption of the electrical appliance or group of devices that will be connected to it.

For example, a 16 Ampere outlet will withstand a total load of 3.5 kW. When connecting it, you must use a 1.5 kW copper cable, but it is better with a small margin, 2.5 kW, given the current quality of the cables.

Therefore, to protect such an outlet and the conductors to which it is connected, a 16 Amp circuit breaker is required. In this simple way, you can calculate how many kilowatts a machine can withstand at 16, 25, 32 and 40 Amps.

For speed and convenience of calculations, you can use the table:

• A 10A circuit breaker will withstand a load of 2.2 kW;
• A 16A machine will withstand a load of 3.5 kW;
• A 20A circuit breaker will withstand a load of 4.4 kW;
• A 25A circuit breaker will withstand a load of 5.5 kW;
• A 32A machine will withstand a load of 7 kW;
• A 40A circuit breaker will withstand a load of 8.8 kW.

You should know that you can find Chinese circuit breakers that do not hold the declared load at all.

The above calculations are valid for normal machines, or those that were released in the Soviet Union.

General information about machines

Automatic switchboards

As a rule, automatic circuit breakers contain three types of electrical circuit releases: thermal, electromagnetic and mechanical. The first is designed to protect electrical circuits from overcurrent, the second - from short circuits in load circuits, the third - for operational switching of electrical circuits.

There are electrical circuit breakers that perform protective functions against overload and electric shock (ES). These are switches controlled by differential current with built-in protection against current overloads - difavtomats (DV).

Main technical characteristics of automatic circuit breakers (AB)

Ratings of machines for various electrical networks

Rated voltage is the value set by the manufacturer at which the AV’s performance is determined.

Rated current is the current established by the manufacturer that the AV is capable of conducting in continuous mode, in which the main contacts remain closed at the specified control ambient temperature (standard +30 °C).

The switch frequency is the industrial frequency for which the device is designed and to which the values ​​of other characteristics correspond.

The rated maximum breaking capacity is the value of the ET, which can turn off the AV while maintaining its functionality.

The current limiting class is characterized by the shutdown time between the beginning of the circuit breaker opening and the end of the arc time. There are three classes of current limiting:

• the shutdown time of class 3 AB occurs within 2.5 – 6 ms;
• 2 classes – 6–10 ms;
• Class 1 – more than 10 ms.

There are several types of protective (time-current) characteristics of AV, the most popular are B, C and D

Protective characteristics of C, B and D machines

We supply BA47‑29 circuit breakers with rated currents from 0.5 to 63 amperes with protective characteristics B, C or D.

Introduction

• to protect networks: from short circuits - an electromagnetic release is built in for this purpose;
• from overloads - a thermal release is built in for this purpose;

A thermal and electromagnetic release is installed in each pole of the machine and together they are called a combined release.

Characteristic C, B or D determines the strength of the short-circuit current at which instantaneous protective operation will occur, and therefore the places where the machine with a specific characteristic will be used. The operation is caused by an electromagnetic release.

On the left is a photograph of VM63 modular switches with an analysis of the inscriptions (“what is what”).

Differences between circuit breakers with characteristics B, C and D

where In is the rated current of the circuit breaker.

Examples:

1. A circuit breaker with a rated current In = 6 amperes with characteristic B: will not trip* with a short circuit of 18 amperes (3·In), but will switch off instantly with a short circuit of 30 amperes (5·In) and above.
2. A circuit breaker with a rated current In = 16 amperes with characteristic C: will not trip* with a short circuit of 80 amperes (5·In), but will switch off instantly with a short circuit of 160 amperes (10·In) and above.
3. A circuit breaker with a rated current In = 50 amperes with characteristic D: will not trip* with a short circuit of 500 amperes (10·In), but will turn off instantly with a short circuit of 2500 amperes (50·In) and above.

*By the words “will not work” we mean will not work under the influence of an instantaneous electromagnetic release. But there is a thermal release that will heat up within a few seconds and turn off the network.

At the same time, the standard does not indicate how the switch will behave in the range itself (the error is included). Tests are carried out only in boundary positions (according to table 6 on page 19 of the GOST 50345‑99 standard):

• lower limit (3, 5 and 10 from In, respectively) – shutdown does not occur within 0.1 seconds;
• upper limit (5, 10 and 50 from In, respectively) – protective operation occurs within 0.1 seconds.

Circuit breaker characteristic B

• long cable lines;
• circuits with a heating element (heating element, electric oven, boiler);
• secondary circuits or networks with high resistance and low current (which causes low-level short-circuit currents): alarms;
• management;
• measurements.

Characteristic C of circuit breaker

• apartment and office sockets;
• lighting in the kitchen, bedrooms; in the bathroom, in the office, in the workplace;
• individual consumers (without powerful engines).

Characteristic D of the circuit breaker

• washing machines;
• dishwashers;
• pumps for drinking water intake;
• welding machines.

Why are only machines with characteristic D suitable? At the moment the electric motor starts, starting currents appear that are 5-7 times greater than the rated (operating) current. After acceleration, the current consumption is equal to the rated current. If you install a switch with characteristic C (short circuit shutdown in the range of 5-10 rated current values), it will “confuse” the starting current with a short circuit and turn off the network. To prevent false alarms, switches with protective characteristic D are used.