What is the difference between an RCD and a differential circuit breaker and which is better to use? Automatic or differential circuit breaker: how to distinguish and what to choose. How are differential circuit breakers and differential load switches different?

When developing a power supply scheme or overhauling electrical wiring, it is important to provide reliable protection against short circuits in the network. Here the question arises about what is better to use in each specific case: an RCD or a difavtomat. Both of these devices are classified as protective. They increase the level of security and even look similar to each other; at first glance, the difference is minimal. Therefore, the difference in application is not so obvious.

Protective automatic device in the apartment panel

Many simply do not know which of these devices is installed in the apartment panel and do not understand what the difference between the devices is and how to distinguish one from the other. Until something happens to the wiring, questions about replacing the RCD or how to use the automatic device simply do not exist.

Definitions

The RCD turns off the load when the differential current value is higher than permissible (GOST 31601.2.1-2012). The full name in Russian is residual current device, and the English abbreviation of the name RCD is residual current device. Despite the designation RCD accepted among electricians, the correct name will sound like a differential switch. The same name will be on the product label.

This mechanical device of a communicative type is triggered by a change in the vector difference of currents arising in the transformer included in the differential switches.

These changes occur when a person touches live parts, as well as in the event of overheating or fire caused by current leakage. Residual current devices are installed not only in power supply systems, but also in some household appliances that are used in damp areas, for example, in certain models of hair dryers.

RCD operation diagram

A difavtomat or automatic differential current switch has greater capabilities compared to a differential switch. It combines a residual current device and a circuit breaker (GOST R 51327.1-2010). Due to this combination, the difavtomat protects against electric shock in the event of leakage or contact with live fragments, and also protects against overloads and short circuits using the machine. The difavtomat prevents fires that may occur when the insulation catches fire due to overheating.

Differences

The main purpose of the residual current device is to control current leakage, as well as monitor the flow of voltage to electrical appliances. If all devices on the network are simultaneously connected, the circuit with a differential switch will not respond to the overload, and the wiring will burn out.

Even if a short circuit is forced to be created by connecting zero and phase, the differential switches will not turn off the voltage. The difavtomat, where the residual current device and the circuit breaker work together, is able to cope with all these problems.

Only a difavtomat will prevent short circuits and overloads in the network. Differential switches do not have such functions.

The device of the difavtomat

The main visual differences between the RCD and the difavtomat
It’s not entirely easy to immediately understand from its appearance why one device is called an RCD, and the second – a difavtomat.

The cases in one and the other case are approximately the same, there is a switch, a diagram is drawn on each device, certain parameters are listed and technical characteristics are specified. But upon closer examination it is clear that all these designations are different.

Thus, we can list the main differences by which you can determine what exactly is in front of you:

Name;
connection diagram;
designation of minimum current;
abbreviation.

Let's look at how the protection differs in appearance of the case. Name, abbreviation and minimum current symbols
Before connecting the selected device to the network, carefully examine the case. In most cases, the full name of the security mechanism is located on the back cover.

The abbreviation VD (for RCD) or AVDT (when working with a difavtomat) will be indicated on the front side of the case. In our case, these are the designations VDT1-63, that is, a differential switch and AVDT32 - differential circuit breakers. The differences in the spelling of the designations are obvious; difavtomats are always called differently.

Differences in designation

The front side is also different. If a large letter and numbers behind it are visible on the case, then this is a difavtomat (we have C 16), but if all the letters come after the number (32 A) - this is an RCD. These numbers indicate the rated current in the circuit.

The rated current is determined based on the power of the electrical appliances used and the cable cross-section. The letter before the designation of the rated current indicates which releases (electromagnetic and thermal) are used in the network.

If you can’t figure out how to distinguish one device from another, then you can’t risk installing protective devices yourself. Call a qualified electrician who will decide where to use the differential breaker and where to use the differential switch together with the breaker.

Connection diagrams

There is a difference between the connection of such protective devices to the network and the circuitry of the device itself. In the operation of a differential switch and when using a differential switch, different, although similar, principles are used. It is important to distinguish them from each other.

Differential switch diagram

In the picture with a difavtomat, there will definitely be symbols of a thermal release in the form of a semicircle with the letter “P” connected together. This release instantly reacts to overloads that occur in the network, and the circuit breaker turns off the current. It is possible to distinguish different defense mechanisms based on this feature.

Diagram on the body of the difavtomat

What's better

It is impossible to choose between different types of protective devices without taking into account the individual characteristics of the network. After all, it is important not only to correctly select the parameters of the differential switch or the necessary characteristics for working with the differential switch, but also to assess whether there is enough space for them in the panel.

You can choose a scheme where differential switches and circuit breakers will act as separate elements of the circuit, or you can still take a separate differential circuit breaker. Although there is not always enough space in the shield to accommodate more bulky circuits on the flight, to which protective structures are attached. In this case, a difavtomat would be preferable.

It is much easier for a professional electrician to install only one device than to tinker with several at once. In addition, each additional break in the network means a loss of power and a possible leakage of current. Therefore, experts most often advise using a differential circuit breaker instead of an RCD with a circuit breaker in combination.

But on the other hand, replacing a differential switch or automatic machine separately will be cheaper than buying a differential switch when the device fails. When a differential circuit breaker is triggered, it is difficult to determine the cause of network failures. After all, this device responds to any critical changes in the operation of electrical wiring and devices.

But when a circuit is triggered in which a differential switch and an automatic circuit breaker are used separately, such a problem does not exist. Differential switches register current leakage, and the automatic switch registers voltage surges. This makes it much easier to find the source causing power supply problems. This is especially necessary if several different electrical appliances are connected to the network.

Today, when the number of electrical appliances used in everyday life is constantly growing, it is not always possible to track the level of total power. If a common automatic circuit breaker is installed for a group of electrical consumers, it will need to be replaced entirely as the load increases. If a combination of a switch and a machine is used, then it will be enough to select a new RCD with the required characteristics.

If you need to protect electrical wiring from network interruptions caused by the operation of a specific high-power electrical appliance, it makes sense to install a differential circuit breaker only in this area.

The main thing is to select the device parameters so that they clearly monitor the operation of a specific unit, for example, a washing machine or boiler.

General difavtomat for a group of electrical appliances

In an emergency, when protective devices fail or the RCD needs to be replaced, it is temporarily possible to connect the machine using a jumper without a differential switch. Thus, power supply to houses will be restored. If the automatic switches fail, the room will be de-energized until the protective device is replaced.

The cost of a set with a differential switch and an automatic machine will be higher than if differential automatic machines are used. In terms of quality, imported copies are more reliable. Although domestic devices also work well, they are inferior in such an important characteristic as response time and are more susceptible to mechanical damage.

There are models where indicators are used when working with a differential automatic device, which show when differential currents trigger the device. With such a protective circuit, it is possible to determine what caused the network outage.

When repairing electrical wiring in an apartment or house, you can use different connection diagrams for groups of electrical appliances. It all depends on the purpose of a particular network line, as well as the power of the devices installed on it.

Why does the meter turn off when using new protective devices?

Electrical wiring in old apartments and houses was carried out taking into account requirements that are not relevant today. Therefore, situations often arise when the machines are selected correctly, the owners know where to use a differential switch with a machine, and where to get by with just a differential switch, but the lights still turn off. There are several reasons for this phenomenon:

the use of old aluminum cables in electrical wiring, which, unlike copper ones, are used to the limit of their capabilities;
poor quality installation of new wiring.

Therefore, it is necessary not only to correctly use the differential switch or differential switch, but also to monitor the operation of the entire network.

What's better. Video

This video will help you finally decide on the choice of a difavtomat or RCD. Here are the main advantages and disadvantages of each of them.

Before choosing between one or another protection, it is important to consider how and why you need to secure the premises. Using one RCD will not protect against sudden voltage surges, but it will protect against current leakage. Diphavtomats will cope with any problems on the network, but it is better to use them not for a group, but for a separate powerful unit.

All electrical devices are different from each other, but the devices can perform similar functions. Today we will discuss automatic devices and RCDs, what is the difference and what is their operating principle. First we consider the question of what each of these devices is.

An RCD, in simple words, is a protected shutdown device installed in apartments and in places with a risk of sudden changes in electrical voltage. The advantages and functions of this device include the ability to recognize the difference and strength of current. In the event that there is an increase in the current passing through the device, the system simply opens the network, which makes it possible to stop the short circuit, as a result of the occurrence of a fire hazard or electric shock. Often this device consists of several elements, each of which is responsible for a specific function.

A differential circuit breaker has a significant difference from an RCD, but their task is similar. So, this device is a combination of an RCD and an ordinary machine into one whole. This equipment is used to prevent electricity leakage, short circuits and network overload.

Differential circuit breaker

This device contains thermal and modular protection, which creates maximum comprehensive safety from all possible dysfunctions.

When answering the question of how an RCD differs from a difavtomat, it is important to highlight that the first device performs a protective task only in the presence of voltage leakage from the wiring. Such equipment will be able to turn off the power immediately at the moment of risk and a short circuit. The design of the device plays the role of a power relay in the electrical circuit.

Tsugunov Anton Valerievich

Reading time: 3 minutes

To ensure safe operation of the electrical wiring of modern apartments, today they are increasingly choosing residual current devices (RCDs) or differential circuit breakers. The use of each of them ensures early shutdown of the section of the electrical circuit in which there are insulation faults. In addition, with the correct organization of automatic protection of the electrical network using such devices, reliable disconnection of consumers is ensured in the event of overloads or short circuits. At the same time, the main difference between an RCD and a difavtomat is the need to install and use an additional circuit breaker together with such a device.

It should be noted that for the correct functioning of protection against large differential currents, it is necessary to have a three-wire single-phase system, which includes a grounding wire. Such a wiring system is now widely installed in new buildings, but is extremely rare in old houses.

To answer the question of how an RCD differs from a difavtomat and which device is more preferable to choose for use in your apartment, you need to familiarize yourself with their main technical characteristics, operating principles, as well as design and operation features.

Application of RCD

It is used for switching in a network that supplies groups of consumers during the flow of currents operating under normal operating conditions.

The main task of the RCD is to disconnect a section of the electrical system if a differential current occurs in it that exceeds the permissible value.

The occurrence of leakage current is explained by the presence of some insulation resistance of the wiring and electrical consumers. Since this resistance cannot be infinitely large, the so-called normal leakage current will always flow through it, the value of which must be within certain acceptable limits.

In order to better understand what unwanted processes occurring in the electrical network the RCD or RCD protects from, consider the following diagrams.

The first of them depicts a case of electric shock to a person, which occurs as a result of touching the ungrounded body of an electrical device with broken insulation. This circuit has a circuit breaker that disconnects its contacts in the event of an overload current or short circuit, but such protection does not operate when a phase is shorted to ground.

The second figure shows the path of leakage current when the insulation of the grounded body of an electrical appliance is broken. Since the resistance of human skin is much higher than the resistance of the ground loop, in this case electric shock does not occur. However, the metal parts of the housing have a certain potential relative to ground.

The third diagram shows an electrical circuit in which, in addition to the circuit breaker, an RCD is used. If a leakage current occurs, the value of which exceeds the rated value, the automation breaks the circuit.

If you use such protection in electrical networks whose consumers are not grounded, then for it to operate it is necessary to create a closed circuit between the metal body of the device and the ground. As a rule, such a circuit closes if a person touches the body of the electrical installation.

Thus, the use of an RCD allows you to open the electrical circuit in the following cases:

If a person touches an ungrounded electrical installation body that is energized due to insulation damage.
If a leakage current occurs through the grounding loop due to a violation of the insulation of live parts, the value of such current must exceed the permissible value.
In case of incorrect connection of the neutral and ground wires in the electrical installation.
When the neutral wire breaks.

The characteristics of each model are marked on its body in the form of special markings. The main ones are:

Rated current and type of time-current characteristic, for example, C63. This means that the rated current is 63 A. The time-current characteristic is the dependence of the tripping time of the switch contacts on the current flowing through them. For circuit breakers used in power supply systems of various objects, these characteristics vary. In apartments and residential buildings, machines with C-type characteristics are used.
Leakage current (0.03 A, 0.1 A), at which that part of the circuit breaker that responds to the magnitude of the differential current is triggered.
Rated voltage (230 or 400 V).
Type of machine (for working with alternating or rectified direct current).
Schematic diagram of connection.

To answer the question of how to distinguish an RCD from a difavtomat, just look at their appearance. Although at first glance the differences are not very noticeable, for a knowledgeable person they are, as they say, obvious:

The RCD does not indicate the type of time-current characteristic.
The difavtomat has two additional switches in the circuit diagram printed on its body, indicating thermal and electromagnetic releases.
Name of the device (VD or RCBO).

A residual current controlled circuit breaker has the following advantages:

When installing the difavtomat, there is no need to install any additional protective equipment.
Almost all such devices are equipped with a special indication that allows you to accurately determine what triggered the device: a large leakage current, a short circuit or an overload.

When answering the question posed, how does an RCD differ from a difavtomat, you need to consider the following. Judging by the quantity and quality of the functions performed, there is not much difference in which device to choose: a difavtomat or an RCD. Moreover, the cost of the combined device is even higher than the combined price of an RCD and an ordinary machine. In addition, if one of the separate devices fails, you can repair or replace it without removing the second one; this is much cheaper than repairing a difavtomat.

Most people are not very well versed in the types of electrical protection devices, so they often do not understand the difference between them. In fact, these devices are designed to solve different problems, and therefore even an ordinary resident needs to know how they differ and what function they perform, at least in general terms. An RCD is often confused with a differential circuit breaker. After reading the article presented to your attention, you will learn what is the difference between an RCD and a difavtomat, and you will also be able to understand when and which of these devices is better to install.

RCD and differential circuit breaker: tasks performed

If you put an RCD and a breaker next to each other, their similarity will be immediately noticeable. Indeed, such devices are easy to confuse. But they perform different tasks. The RCD provides protection for people and pets from electric shock - this is its only function. If the power line or any of the devices connected to it are damaged, leakage current may appear in the circuit. If you touch such wiring, you can receive a strong electric shock.

In addition, an electrical leak can cause the insulation to overheat and subsequently melt, which often leads to a fire. Installing an RCD will solve this problem - when a leakage current is detected, it will operate and the circuit will be disconnected. After troubleshooting, the device can be turned on again.

However, this device does not provide protection against all possible problems with the cable. Protecting the line from leaks, it does not respond to overloads or short-circuit currents. To avoid these problems, it should only be installed together with a circuit breaker. Another option is to connect a differential circuit breaker to the power supply instead of an RCD.

The difference between the devices is clearly shown in the video:

First, let's explain what a difavtomat is. This is the name of a protective device that is capable of simultaneously performing the work of an RCD and an AV. Thus, he will be able to save the line from any possible disturbances (current leakage, short circuit, overvoltage). Simply put, this is a regular circuit breaker for an electrical network with an RCD included in it.

The residual current device itself can be compared to a leak indicator, which will show whether electricity is flowing to consumers or going outside. There is a leak - the RCD trips and de-energizes the network.

If it is not there, the device will not notice any overload or short circuit. Therefore, if you are thinking about what you still need - an RCD or a circuit breaker, and do not know what to choose to protect your home line, then remember: the first is not a self-sufficient device and cannot be installed in a line without a circuit breaker. The difavtomat itself can protect the network from the problems described above and does not require additional equipment.

The difference in appearance between an RCD and a differential circuit breaker

Determine which device is in front of you - an RCD or a differential device. automatic – quite easy even visually. Despite the external similarity (switch lever, the presence of a “Test” button, the same body part with a diagram printed on it, as well as numbers and letters), it is enough to look closely to see that the designations on these devices are different. We'll talk about this below. It’s even easier to determine whether the RCD or the automatic circuit breaker is in front of you by the location of the “Test” button and switch. For RCBOs, the lever is located on the left, the button is on the right, but for RCDs it is the other way around. This can be clearly seen in the above photograph.

RCD and differential automatic device: differences in markings

The next question is: how to distinguish an RCD from a difavtomat by one of the signs - the markings applied to its body part.

On the surface of the RCD, the rated current is indicated exclusively by numbers. The Latin letter (B, C, D) in front of them is an integral feature of the RCBO.

Let's look at the above photo again. The body part of the RCD is marked “16A”. It means that the rated current in the circuit in which this device is connected should not exceed 16A. RCBOs designed for a similar rated current are marked “C16”. The letter indicates the characteristics of the built-in releases.

Several ways to distinguish an RCD from a difavtomat in the video:

Differences between devices according to the electrical circuit

The circuit is applied to many devices. When looking at the RCD or differential. machine, you will notice that the diagrams printed on them are similar, but not identical. There is an oval on the VD diagram - this symbol indicates a differential transformer, which is the main part of the device. It is responsible for detecting leakage current. The distinctive symbols on the RCBO diagram include the designations of releases - an electromagnetic solenoid and a bimetallic plate, which ensure that the circuit breaker operates when short-circuit currents or overloads appear in the circuit.

There are no release symbols on the residual current device.

Abbreviation on the body

Since manufacturers know that ordinary people are often confused about these devices, many of them put the corresponding abbreviations on the side of the case. The residual current device corresponds to the letters VD (differential current switch), the technical abbreviation of the difavtomat is AVDT (which means automatic differential current switch).

This sign allows you to accurately understand what a specific device is - an RCD or a differential circuit breaker. Unfortunately, such designations are found only on devices from Russian manufacturers; imported devices do not have this marking.

RCD and differential AV: which of these devices to choose?

So, we figured out how an RCD differs from a difavtomat. Now let’s move on to the question that is often asked on forums: “Which is better – an RCD or a differential?” Indeed, considering that the RCBO consists of two devices in a complex, provides reliable protection of the network from leaks, overloads and short-circuit overcurrents, without requiring additional devices, we can come to the conclusion that in any case it is necessary to install a difavtomat.

But it is not so. Let's look at this in more detail.

As for the price, the RCBO is more expensive than the residual current device. However, the total cost of the RCD and AV is higher than that of a differential circuit breaker. In this regard, buying the latter is more profitable.

In terms of operational reliability, these devices are identical. Only devices from different manufacturers may differ. Russian-made devices cannot be called bad, but they are still inferior to most foreign analogues in response time, and the quality of the material from which the body part of domestic products is made is worse. Naturally, the price of imported devices is higher than those produced in Russia.

Now let's talk about the disadvantages inherent in RCBOs as a combined device. If the RCD and the circuit breaker are installed separately, then in the event of a problem in the circuit, one of them is triggered: in the event of a leak, the VD, and in the event of an overload or a short circuit, the AB. This greatly simplifies troubleshooting. If the automatic switch works, you will have to spend a lot of time to find out the reason for its shutdown. True, taking into account this feature, some modern RCBO models are equipped with operation indicators that allow you to determine why the device was turned off.

Another possible problem is breakdown. Any equipment can break down, protective devices are no exception. If one of the devices in the RCD-AV chain fails, replacing it will cost less than installing a new automatic circuit breaker. In this case, one of the parts of the RCBO may become unusable, and the entire device will have to be replaced. Therefore, when choosing between these devices, you need to take into account the stability of the network and the risk of possible problems.

As for ease of installation, the RCBO is preferable in this regard - installing it in a switchboard is easier and faster than two devices.

Possible errors when connecting RCDs and breakers on video:

Conclusion

In this material, we figured out what a RCD and a differential AV are, what are the features of their functioning, and also how a VD differs from a machine (differential). Remember that when choosing an RCD or a circuit breaker to protect the network, you need to pay attention to the parameters of the protected line. For example, in an apartment or small private house, you can install both a residual current device separately with an automatic circuit breaker and a RCBO - there is no fundamental difference in this.

As for large buildings with a large number of loads (for example, cottages with boiler rooms and utility units), it is better to give preference to a differential automatic machine.

Today, differential circuit breakers are widely used to protect single-phase and three-phase electrical networks, ensuring, during the operation of electrical equipment, life safety and human health. In addition, difavtomats are used as devices that prevent the fire of electrical equipment due to insulation faults. What is a differential circuit breaker and how does it differ from an RCD?

Differential automatic machine: what is it, principle of operation

What is a differential automatic machine in electrical engineering? This is an automated differential current switch of various types (interpretation of RCBO), designed to protect a person from injury during electric current leakage when touching conductive parts of electrical equipment. At the same time, a difavtomat is needed to protect electrical networks from current overloads and connections of two points of an electrical circuit with different potentials.

Structurally dThe differential machine consists of:

Working part with automatic switch;
The protective part, presented in the form of a differential protection module.

In the working part of the device there is an independent release for protecting the circuit and a rail that turns on the device. At the same time, the difavtomat is equipped with two types of releases - thermal and electromagnetic. The differential protection module is responsible for promptly identifying leakage currents in the electrical network, converting electricity into mechanical power, and influencing the circuit breaker reset rail. The switch on the machine can be either two- or four-pole.

The operating principle of a differential circuit breaker is based on the conversion of differential current in conductors supplying the load to the protected electrical installation.

A special sensor located in the protective module – a differential transformer – compares the current passing through the device at the input and output. If there is a difference between the values, then the transformer converts the differentiated current into mechanical energy, which drives the reset rail and the device turns off.

What is the difference between an RCD and a differential circuit breaker?

How, then, does a residual current switch differ from a residual current device (not to confuse an RCD with a RAM)? So, the second device is a switching device, the main purpose of which is to protect electrical wiring solely from current leakage. In addition, the disconnect device serves as a mechanism to prevent electric shock.

The differential circuit breaker combines the functions of both a protective switch and a circuit breaker.

This is the main difference between the devices. The difavtomat, unlike an RCD, protects the network not only from current leaks, but also from overloads and short circuits at two network points with different potentials.

As for the RCD, if powerful consumers are simultaneously connected to the network and an overload is created, it will not work. This, in turn, can lead to a fire in the electrical wiring. The RCD will not work even if the phase is shorted to zero. Therefore, it is always connected through a single-module input circuit breaker. These devices work in tandem: the RCD identifies a leak and protects a person from electric shock, and the circuit breaker protects the line and electrical equipment from excessive load and short circuits.

VD1 63 DIF or RCD: how to distinguish

In order to achieve the most effective protection of the power line, it is necessary to be able to distinguish between automatic shutdown devices, because visually the circuit breaker looks similar to a safety switch. So, having determined that you have an RCD, you can take measures to protect the line from overloads and short circuits by adding a circuit breaker to the connection diagram. Identification will also be necessary if you need to replace a particular device. How can we find out what type of device is in front of us?

To help identify the protective device:

Inscription on the body. All domestic protection devices have full names in Russian. To identify imported devices, you will have to translate the names.
Marking. On a difavtmoat, the letter designation comes before the number (for example, C16), on an RCD it is the other way around.
Abbreviation. To understand what device you have in front of you, you need to decipher the abbreviation. So, on domestic RCDs it is written VD - differential switch (for example, VD1 63), and on difavtomats - AVDT, which stands for automated differential current switch (for example, AVDT32).
Connection diagram. Almost all devices have pictures with connection diagrams on the case. So, if in the diagram we see only a differential current transformer, then we have an RCD; if there are also images of the windings of thermal and electromagnetic releases, then this is a differential current transformer.

Its dimensions will help us to tell which device is in front of us. So, the difavtomat will be slightly wider than the RCD. But this identification criterion may not be justified on modern devices.

Difavtomat: types

Like an RCD, a diff can be of an electronic or electromechanical type. The first type differs from the usual one in its more compact dimensions. In addition, automatic devices differ in sensitivity and response time.

According to GOST, the response time of the differential machine should not exceed 0.3 seconds.

In terms of sensitivity, difavtomats can be low-sensitive (more than 30 mA) and highly sensitive (from 10 to 30 mA). The former will provide protection against electric shock due to indirect contact with sections of the conductor without insulation. The second - with direct contact. In addition, highly sensitive difavtomats are recommended for power supply in rooms with high humidity. Separately, there are fire diffs with sensitivity up to 500 mA. In addition, difautomatic devices are divided into types according to the form of current leakage.

So, according to the type of current they distinguish:

Devices for protecting installations from sinusoidal alternating current leaks (AC type);
Automatic devices for protection against leakage of alternating sinusoidal and pulsating leakage currents (A type);
Automatic switches for protecting equipment from leakage currents of all types (B type).

Separately, devices without overcurrent protection (VDT) are distinguished. Such machines are sensitive to leakage current, but they are unlikely to be able to protect electrical equipment from overloads. To do this, they should be connected to the electrical wiring in conjunction with a fuse.

Selecting a differential switch

In order to choose a differential switch for an apartment or private house, you need to know the type of electrical network at the site and the technical characteristics of protection devices. So, depending on the type of network, you can choose a single-phase or three-phase automatic circuit breaker. The rated voltage of the first type of machine will be 220V, the second - 380V.

In addition, when choosing a differential switch, you must consider:

The current for which the device is designed. This value is taken based on the power consumed by household appliances with a margin of 1.5-2 times.
Device rating based on leakage current type. So, for single sockets they use circuit breakers with a rating of 10 mA, for group networks - with a rating of 30. At the entrance to a living space, breakers with a rating of 100-300 mA are usually installed.
Release characteristics. A machine for home electrical networks with a mixed load and moderate starting currents is designated by the letter “C”.
View of the RCD built into the machine. So, for lines supplying powerful household appliances, it is better to use machines with type A RCDs.
The device contains a protection unit against breakage of the neutral working conductor. Such a block is essentially a device with breaking contacts, and serves to prevent current leakage through a phase after a zero break.

The manufacturer is also important when choosing a automatic machine. Thus, one of the leaders in the production of electrical equipment and automation equipment is the Swedish-Swiss company ABB. Good devices in terms of price and quality are made by the French company Legrand.

How to connect a diffautomat

There are two ways to install and connect the difavtomat to a household power supply. So, the device can be installed at the input of an electrical circuit, and at the input of a certain electrical group.

At the same time, the difavtomat is connected observing the polarity to the line that it will have to protect.

In the first case, the groups are separated by electrical switches, the power wires are supplied to the upper terminals of the machine, and the load on each individual group is removed from the lower terminals. The main disadvantage of this connection is that when the machine is turned off, all electrical appliances in the room are turned off. Therefore, they often choose the second, most reliable and convenient option. At the same time, the grounding contact for any type of connection goes from the distribution panel directly to the consumers.