RCD: device, types, connection with and without ground, causes of operation. How to connect an ouzo - step by step instructions Is it possible to exclude grounding

Having decided on the rating and manufacturer of the RCD, you can begin its direct connection. Devices of this class are mounted in a protective electrical panel, which must comply with the technical conditions for this electrical network, be spacious enough to accommodate circuit breakers and connecting wires.

As a rule, a metal electrical panel is installed at the input of the network. Some of its varieties are locked, have a separate sealed compartment for the electric meter. For outdoor installation, the electrical panel must have a robust anti-vandal housing and weather protection.

To connect individual groups of users through the RCD, it is better to install it directly on site. In this case, plastic shields are used, they are cheaper and more aesthetic. They can be both overhead and wall-mounted or drywall constructions.

From simple to complex

The presented simplest RCD connection diagram makes it possible to understand the principle - the neutral wire after the protective device must be insulated as well as other conductors. It must not come into contact with either the input neutral conductor or the PE ground wire.

The principle of connecting RCDs with machines

Understanding this simple rule will allow you to independently assemble a shield of any configuration, no matter how complicated the circuit may seem. Another important rule is to use a circuit breaker in series with the RCD.

This circuit is great for connecting one or more parallel-connected sockets, and can be successfully used to power electrical appliances in the bathroom, kitchen, garage or basement.

Scheme with several circuit breakers

This type of connection can be used in the input shield, to protect the entire apartment with the help of one RCD. The image shows that in addition to additional circuit breakers, a new element has appeared - a zero bus insulator mounted on a din rail.

zero tavern

The fact is that after each switch, a phase wire comes out, which is paired with a neutral conductor to its consumer. These neutral conductors must be electrically connected to the output terminal N of the circuit breaker. It is clear that with a large number of them, they simply physically will not fit into the clamp.

Some electricians file the current-carrying cores if the cables are single-core, or bite off a few cores in multi-core cables to squeeze the entire twist of the neutral wires into the connection socket. This is highly undesirable due to the fact that the cross section of each sawn conductor will be smaller, respectively, there will be more resistance and heating.

Many contacts at one point will also create additional heat dissipation, exacerbating the situation. The solution to this problem is to connect neutral conductors to an isolated zero bus.

These products are available with different numbers of mounting holes of different diameters. The insulators that hold the busbar can be mounted both on the DIN rail and on the shield body. The PE ground wire bar is attached directly to the housing.

The connection of all neutral wires into one bundle is also undesirable due to additional difficulties in finding a fault on the line, or when dismantling one of the cables - you will have to unscrew the clamp once again, unwind the twist, which will lead to microcracks in the conductive cores.

But simultaneous installation of two wires in one socket is allowed, as can be seen from the figure, the inputs of the circuit breakers are connected by jumpers. Professionals for these purposes use special connecting tires, called "combs".

"comb"

Copying the previous diagram

To install selective multilevel protection, you need to use the previous scheme, simply copy it, and paste it to a lower level, adding or removing circuit breakers, changing the rated current and the differential tripping current of the protective device.

The input RCD in this case should be of type S - selective. In the above diagram, we have a series and parallel connection of the RCD. In this way, you can assemble an arbitrarily complex protection system.

It is also worth noting that the connection of a three-phase RCD is fundamentally no different - instead of single-phase machines, three-phase ones are used. Electric motors can be connected in three phases without a neutral wire.

Preliminary preparation

Electrical panels must be provided with fastenings for 35mm DIN rails. In some products, it is installed by the manufacturer initially. When installing the RCD directly at the place of its operation, the connection diagram must be in front of your eyes in order to avoid mistakes and confusion of wires.

Arrange the machines and connected devices in such a way as to avoid excessive interlacing of conductors. The entire system assembly should look ergonomic and aesthetically pleasing.

And the point here is not the beauty of the work done, but the fact that later, when repairing, replacing, or connecting additional elements, it will be easier to figure out all the intricacies of wires. For the same reason, you need to stock up on a multi-colored cable of the VVG type, corresponding to the section currents. It is also worth using an insulating PVC tube (cambric) for marking conductors.

To install RCDs and other machines with your own hands, you need to have the minimum required set of tools:

• screwdriver
• pliers;
• knife or strippers;
• wire cutters.

Professional electricians use special pliers (strippers) to strip the insulation. With a small amount of installation work, you can get by with a knife, trying to carefully remove the insulation without damaging the core. But for stripping many cables, it is better to stock up on a specialized tool - it will be faster and more reliable.

Don't make mistakes

With such an extensive system of wires, it is easy to make a mistake, especially if the entire installation is carried out in one shield. It is necessary to connect each RCD in stages, starting from the input, ending with the reduction of neutral wires to an isolated zero bus, for each RCD its own.

It is very important not to mix up the neutral wires from different protection devices. In addition, the correct installation of sockets plays a key role: if the neutral wire is confused with grounding somewhere, the device will work immediately when the load is turned on.

Polarity

Among some electricians, there is a belief that the RCD can be connected in any way, changing the neutral and phase conductors. For electronic RCDs, such neglect of the rules can be fatal - the internal power will fail.

Electromechanical devices will work, but there will be nuances during shutdowns - the phase contact opens a fraction of a second faster. Since the manufacturer indicates the marking of the conclusions, then he carried out the appropriate tests and calculations.

Some of the electricians, trying to save on wires, can connect the RCD “from the bottom up”, swapping the input and output. The device will work, but the arc extinguisher may fail in this case, and under heavy load, at the time of protection operation, several thousand degrees of plasma can cause a disaster. You should not experiment with the correct connection, you must always observe the polarity.

Installation culture

It is important not to allow tension or sagging of the wires. The insulation must be removed for the entire length of the entry into the mounting socket, but no more. Do not repeatedly bend-unbend the conductors. Clamp the terminals with a suitable screwdriver, preventing it from slipping, do not overdo it with the use of force. Check the reliability of the installation of each wire, twitching it with your hand.

The installation of residual current devices (RCD) is an additional and essential means of protecting a person from electric shock and an excellent device that prevents fire from. This is due to its ability to fix the difference in currents flowing in the phase and neutral wires. Therefore, in case of violations of the insulation of the wires or a break in the neutral wire, the RCD will necessarily turn off the protected section of the electrical network. In this case, overload and short-circuit protection circuit breakers will not react. The installation of RCDs in houses and apartments where there are small children is especially relevant.

Wiring diagram

Before installing the RCD, you must study the diagram of its connection. Part of the connection diagram and graphical representation of the RCD can be seen in the drawing.

On the installation diagrams, the RCD is depicted as a switch with an oval and a line emanating from it, connecting to the switch. An oval means a current transformer through which the controlled conductor passes. The line shows that the current induced in the transformer controls the opening of the switch.

In accordance with GOST 2 755-87, the letter designation of the RCD is indicated above or to the right of the graphic representation of the circuit element. As can be seen from the figure, the letters QD denote the RCD, and below its main characteristics are displayed: type, rated and breaking currents. This is how a single-phase RCD is depicted, a three-phase one is represented by a combined pattern of three single-phase ones, with a corresponding letter explanation.

The image of the installation diagram shows that two conductors approach and exit the RCD: phase and zero, the earth one passes by. It can be seen that first there is an introductory machine for short circuits and overloads, then an electric meter, and only then the main protective shutdown device. Judging by the rating of the breaking current, this is a fire RCD.

Recently, apparently, in order to increase visibility and attract customers, the wiring diagram for connecting the RCD in the apartment began to be depicted with drawings of connected devices. According to them, even an unskilled worker can install an electrical panel with automatic protection devices.

Schema parsing

The image of the installation clearly shows that the phase (red line) and zero (blue) come to the introductory circuit breaker QF1, then to SW1 and only after the meter to the fire RCD QD1. From the QD1 output, the phase wire goes directly to the SF3 overload protector and to the RCD QD2, QD3. Automatic devices SF1, SF2 and SF4, SF5 are connected to these devices, respectively. The neutral wire is connected to the neutral bus N of the apartment shield. The ground wire from the socket groups is connected to the PE ground bus. Correctly connecting the RCD according to this scheme will not be difficult.

Now all electrical panels and their internal dimensions, attachment points are unified under one standard. Circuit breakers are also unified in terms of dimensions and ratings of controlled current parameters. Therefore, any devices, regardless of the manufacturer, intended for installation in an electrical panel, are guaranteed to fit in it. Outwardly, the devices almost do not differ from each other. Since they are modular, they all have the same fastener size. The thickness of the devices may vary, but it changes with a certain step. Only by letter designations and a diagram can one understand the type of device.

In the apartment

Let us analyze the case when the installation of protection equipment takes place in an apartment panel. Some builders, when renting houses with a free layout, rent housing without wiring an internal electrical network. This is understandable, it is not known where the partitions will stand and, accordingly, sockets and lighting. Therefore, they introduce only cable into the apartment.

On the storey electrical panel there is an introductory circuit breaker and an electric meter. The future owner enters into an agreement with another contractor for internal electrical work. The wiring diagram will then change depending on the requirements of the customer. It will depend on the circuit and on the loads which RCD to install. If desired, any man can independently perform these works.

We will assume that the wiring in the apartment corresponds to the protection installation scheme shown in the previous figure. The introductory machine and the counter are located in the floor board, and we will place all other elements in the apartment box. To do this, in the corridor, next to the cable entry point, it is necessary to install an electrical panel. The installation sequence is as follows:

• the input machine is turned off. A sign is posted "Do not turn on, people are working";
• a socket is connected to the cable that was brought into the apartment. It will be needed to connect a working tool and lighting;
• the plate is removed, the machine turns on;
• holes are drilled in the wall with a puncher for the fasteners of the box. Dowels are inserted, and the shield is attached to the wall with screws;
• after that, a metal rail is inserted and fastened to the inner wall of the box with screws.

There should be no difficulties if you follow all the steps consistently and carefully.

Rail Mounting and Grounding

Although the range of electrical panels is large, they are all unified. To make installation as easy as possible, holes and attachment points are made in accordance with international standards. The rail is a strip of metal with a convex middle along its entire length. With its convex part, it is applied to the wall of the box and fastened. Thus, two strips of metal are obtained, located at the same distance from each other and from the wall. They can later be installed protection equipment.

On the back wall of all protective devices there is a special groove and a locking mechanism that allows you to securely mount it to the rail. To do this, you just need to put the device on the top strip and click on the machine. The latch will lock it.

The installation takes place in the following sequence: RCD QD1, QD2, QD3, machines SF3, SF1, SF2, SF4, SF5. This arrangement will require less wire for indoor wiring.

In the lower part of the electrical panel there are places for fastening zero and grounding tires. That's where they need to be fixed. As can be seen from the installation diagram, three pads are used for the zero bus. This is necessary so that the leakage currents are controlled separately in groups SF1, SF2 and SF4, SF5. After that, the devices are connected by wires to each other in accordance with the diagram.

Top and bottom connection

When the installation is being carried out, the question arises, how to connect the wires - from above or below? Although RCDs can be connected from either side, it is better to follow the generally accepted rules during installation when the upper contacts are for the wires from the power source, and the lower ones are for the wires from the receiver.

The wires are pre-cut to size, and the ends are stripped of insulation. The ends are inserted into the terminal blocks and securely fixed with screws. In this case, it is necessary to control that not the insulated, but the bare part of the wire is clamped. The wires used must be single-core and correspond in cross section to the passing currents.

In order not to get confused during installation, you first need to connect the RCD QD1, then all the others in order of location on the rail. The inputs of the RCD QD1 and the output contacts of the automata SF3, SF1, SF2, SF4, SF5 should remain free.

When the work on the internal wiring is completed, five cables should come from the junction boxes to the box: two two-wire from the lighting groups and three three-wire from the socket groups. Phase wires must be connected to the output contacts of the automata SF1, SF3, SF5. Zero wires from SF1, SF2 are connected to the zero bus N1, and from SF4, SF5 to block N2. Ground conductors are connected to the PE bus.

Basically, errors when connecting an RCD consist in combining neutral wires or connecting neutral conductors from other groups, combining ground and neutral wires. In the first case, the RCD gives false positives, in the second it does not respond to current leakage.

Connecting to an incoming cable

At the last stage of the installation, you need to connect to the incoming cable. To do this, they turn off the introductory circuit breaker in the floor board, hang out a warning sign with the inscription "Do not turn it on, people are working."

After that, the main cable is inserted into the apartment shield, and the ground wire is connected to the earth bus, and the phase and zero to the input terminals of the RCD QD1. All machines must be turned off. Then the introductory machine on the floor turns on. After that, RCD QD1 is turned on and the test button is pressed. The device should turn off. If this happens, then it is in working order. Turning it on again, we check the operability of the remaining RCD devices.

I must say that the RCD at the QD1 input is a fire RCD and it is better to choose a selective one with a delay as it. Devices QD2 and QD3 have low breaking currents and protect a person from electric shock.

Some people are very distrustful and want to experience after installation. For such, the following safe verification method is proposed. You need a cartridge with a 220 V bulb and a piece of two-wire cable. One end is connected to the cartridge, and the other to the outlet. When connected to the "phase" and "zero" contacts, the lamp will light up, nothing will happen. When we connect to the phase and the ground wire, the RCD will work, since there is a difference in the currents flowing through the phase and neutral wires, the line will de-energize and the light will turn off. In this case, the automatic overload protection will not react. This clearly shows how the RCD protects people from electric shock.

The means of protection against leaks is a special equipment protection device or abbreviated. The device triggers the protection, prevents the leakage current from reaching a dangerous value and is the main means of protecting a person from electric shock.

For comprehensive protection of equipment, they are used together with. According to the currently accepted standards, RCDs are mandatory for installation in the power supply network, regardless of the purpose of these networks.

How does it work

The RCD works on the principle of comparing two currents that flow through a protective device. In this case, the current at the input of the device and the current at the output are compared. If these values ​​differ, then a protective operation of the device occurs.

To check the operability of the device, the test button is used, when pressed, a trial operation occurs, by which you can determine the protection status.

How to choose and not make a mistake

Regardless of the purpose, the devices are selected according to the following parameters:

1. load capacity. For the device, the magnitude of the current for which its power contacts are designed is important. At face value, they are most often used at 16A, 25A, 32A, 40A, 63A, 80A.
2. Leak detection method. According to the type of leakage detection, they are divided into electronic, the leakage of which is determined by an electronic key, and electromagnetic, the leakage value of which is taken from the magnetic core. Electronic ones are more affordable, but have drawbacks in operation in the form of failure when one of the phases fails.
3. Sensitivity to leakage current. Sensitivity determines the ability of the device to operate. The most sensitive devices for 10 mA leakage current. But their use is limited by the number of consumers due to possible false alarms and the presence of natural leakage currents.
4. Circuit current type. According to the type of currents, they are divided into those operating from alternating current and pulsating current.

According to the number of connected phases, they are divided into two-pole and four-pole. Single-pole for a 220 V network, three-pole for 380 V. In houses and private households, due to the use of a single-phase network, single-pole RCDs are used.

To select a protection device, it is necessary to determine its purpose. According to the purpose, it can be divided into the following types:

1. household- these are single-pole RCDs of low sensitivity with a load current of not more than 50 A. Such requirements are due to the large number of household appliances and the large natural leakage points associated with this. Very sensitive ones will constantly false-trigger. A load current of 50 A is determined by the parameters of electricity meters installed in residential premises, not exceeding this rating.
2. For industrial applications- sensitive four-pole RCDs with high current ratings. These requirements are due to the high current consumption of industrial equipment, the use of a three-phase network and increased requirements for its protection due to its increased danger and high cost.
3. Specialized. Fire-fighting type B are specialized. They are highly sensitive not only to AC leakage, but also to slight DC ripples.

Electronic RCDs are more affordable, but have drawbacks in operation in the form of failure when one of the phases fails

Connection rules

When connecting an RCD, you must follow the following rules:

1. The device must always be installed after circuit breakers, since it is not protected from exceeding the current maximum values;
2. The circuit breakers in the circuit must be of a smaller rating, since the fuse response time is long and the current may be sufficient to disable it;
3. Protected RCD lines must be connected to it otherwise the protection will not work.
4. Connect the device only according to the manufacturer's instructions., for example, it is strictly forbidden to change the input and output of the device. This will surely cause a malfunction and its further unusability.
5. Check the reliability of all connections and exclude possible sparking which in turn can cause a fire.
6. All connecting conductors must be well insulated from each other, must not have damage to the insulation, traces of oxidation. When corrosion centers appear, in an environment with high humidity, leakage through oxides will cause constant protection trips. This can lead to serious malfunctions in connected consumers;
7. Housings of installed elements must not have visible damage or defects.

When corrosion centers appear, in an environment with high humidity, leakage through oxides will cause constant protection trips.

Connection order

It is important to remember that all work with RCDs in the electrical panel is carried out with the power off. The installation process can be divided into 5 steps:

1. switchboard preparation;
2. marking of the shield for the installation of all elements of the electrical circuit;
3. installation of an electricity meter;
4. installation of automatic switches;
5. installation of zero;
6. RCD installation;
7. connection of electricity consumers to the RCD network.

Mistakes often occur during installation. The most common of them:

1. Incorrectly selected element types. The grossest mistake - the rating of the input circuit breakers exceeds the rating of the RCD. The scheme in this form not only poorly protects the network, causes false protection trips, but is itself a potential source of an accident;
2. Installation of the device in front of the counter. Due to the presence of a rather large magnetic circuit in the RCD, the meter readings will not be correct and the representative of the power supply company will not accept such a design into operation;
3. Wiring diagram mismatch neutral poles;
4. Inclusion of neutrals in parallel;
5. Erroneous connection protective earth to neutral.

Wiring diagram "introductory machine"

Currently, as a rule, three-wire house networks with protective earth are used.

The central circuit breaker is installed first in the circuit. Behind it, the electricity meter is turned on and only after it comes the RCD. According to well-known rules, the RCD rating exceeds the ratings of automatic load breakers by an order of magnitude. With such a scheme, it is important to ensure the correct connection of the neutral and phase wires.

1. the presence of only one expensive RCD;
2. a small amount of workspace that is occupied by one device.

The disadvantage of the scheme is:

1. difficulties in finding faulty wiring;
2. the difficulty of selecting parameters for existing consumers.

The disadvantages of this scheme are eliminated by parallelizing consumer groups and installing an additional RCD.

Connection to a three-phase network with grounding according to the "separate machine" scheme

The electrical circuit of a large residential facility implies the presence of a variety of energy consumers. For appliances such as a powerful refrigerator, washing machine, oven, a separate RCD is required. This is necessary to protect a particular device and maintain the performance of others that are not related to it.

The safest switching circuit is a three-wire circuit with grounding, and using a selective four-pole RCD, it becomes possible to connect to a three-phase industrial network. With this scheme, protection against damage to the circuit insulation and from leakage is also provided.

Advantages of the "separate machine" scheme:

1. the convenience of finding a leak in the circuit, since the circuit arms have individual devices.
2. the ability to connect consumers of much higher power;
3. this scheme provides the highest level of protection.

Disadvantages of the "separate machine" scheme:

1. high price due to the large number of blocks;
2. significant volume occupied by the scheme;
3. the impossibility of building such a circuit without the presence of a three-phase power supply.

The power supply circuit from a single-phase source is practically equal in functionality to the previous circuit. In it, you can abandon the selective RCD and thereby reduce the cost, but the load capacity of this network will be much less.

Scheme of connecting the RCD to a three-phase network

Connection diagram without protective earth

Not everywhere and not always the power supply networks are equipped with protective grounding. Often in private households built a long time ago, wiring is done without the possibility of grounding. In this case, the installation of an RCD is not only desirable, but also necessary for the safety of residents.

How will the device behave without grounding? In order for the RCD to perform its functions, the zero bus must be connected to the wire coming from the power input. In this case, the RCD will work as if on its own.

In the diagram, the letter N indicates the neutral wire. Since there is no ground in this circuit, it is incorrect to assign this name to another line.

In the light of the data reviewed, it can be said that protection should never be neglected. Despite some difficulties, even in a two-wire line, it is always possible to install a Residual Current Device. Don't skimp on security.

• The use of RCDs in the bathroom and bath is necessary. Due to high humidity, the conductor insulation does not last long. Lack of protection in the power circuit can be deadly.
• When using a two-wire switching circuit, in no case should a self-made grounding device be installed. Homemade grounding systems are not associated with third-party consumers. For this reason, no one knows which phase of the three will be on your neutral wire when the trunk line breaks.

(see photo below) stands for residual current device. Its main purpose in electrics is to protect wiring from current leakage. For example, due to your negligence, you accidentally damaged the cable insulation and did not notice it. Any contact with bare conductors may result in electric shock. To prevent this from happening, just this electrical product exists, which immediately turns off the electricity in the network when a current leakage is detected.

Please note that leakage can also occur due to the aging of the electrical network. The old insulation simply dries out and bursts, resulting in a leakage current. That is why it is necessary to carry out in time and be sure to connect the RCD with grounding!

The principle of operation is quite simple: the device compares the incoming current through itself (phase) with the outgoing (zero). Ideally, there should be no difference; if a slight difference is detected, the product immediately works. There are others that we talked about in the corresponding article!

Main disadvantages

Among the disadvantages of the residual current device, the following should be highlighted:

1. If protection is installed for everything, then at the slightest threat of a leak, the electricity can turn off throughout a private house while you are away. False alarms sometimes cause a lot of problems, for example, if you leave for a few days and the lights go out, the refrigerator will defrost and the street lights will turn off.
2. Connecting the RCD to the mains does not solve the problem of short circuits and overloads of the wiring line. In the event of a short circuit, the device will simply fail. Therefore, together with the product, it is imperative.

Connection diagram

To your attention, the simplest diagrams for connecting a two-pole RCD to a single-phase network with your own hands. Please note that protection must be installed immediately after the electric meter so that control is carried out for all electrical wiring. It is also recommended to carry out wiring for each individual section of the circuit so that the current is turned off only for the section where the leakage occurs (for example, only to the bath, to the washing machine, or only to sockets).

So we figured out the purpose of the residual current device and the scheme for its self-installation. Now let's move on to the process of connecting to a 220 volt network.

Installation rules

Installing an RCD with your own hands is not difficult even for a novice electrician. Consider step-by-step instructions for connecting in an apartment and a house.

Step 1 - Power outage

First you need to turn off the electricity in the network and check its presence with a multimeter or an indicator screwdriver.

Step 2 - Determine the installation location

It is up to you to decide whether to connect the product immediately after the meter or on a separate section of the circuit. We recommend mounting immediately after the electricity meter, but before the introductory one (to protect the device from short-circuit currents).

Step 3 - Connecting

Everything is extremely simple here - it is necessary to bring and connect the cores of wires in special holes (top and bottom). On the front panel of each model, a connection diagram is displayed, as well as the necessary cores are indicated. For example, the 1-N, 2-N scheme means that the phase and zero are started from above, and the phase and zero are also output from below (polarity must be observed). If there is no phase and zero marking by color, they can be found with an indicator screwdriver (the light will not light up when you touch the zero core).

Step 4 - Control Check

After the RCD is fully connected, it is necessary to check its capability. This can be done using a specially designed test button on the front panel. When it is pressed, a leakage current is simulated, as a result of which the residual current device should work. If everything worked, the installation was done correctly.

Installation errors

As in any business, dangerous mistakes can be made during electrical work. To prevent this from happening to you, now we will tell you the most common errors in connecting RCDs with your own hands:

1. The supply wire is wound from the bottom of the case. You do not need to do this, because. even in the product diagram, the supply wire is connected from above. If connected incorrectly, the unit may be damaged.
2. After the RCD, a circuit breaker is not installed. As we have already said, the residual current device does not work in the event of a short circuit, which can immediately disable the product. That is why be sure to connect the machine in the right place.
3. Local protection devices are not installed on separate sections of a large electrical network. As a result, a leakage may occur, due to which the power will be cut off throughout the room.

Basic errors during connection

Video instructions

To your attention is a video instruction on connecting a two-pole RCD to the electrical wiring in the house.

- this is a residual current device, its purpose is to protect people from electric shock in case of breakdown of electrical equipment, or involuntary contact with metal parts of electrical equipment in case of current leakage. Also, it can protect the power grid from ignition of the wiring during a breakdown of current to the case or ground.

The RCD is a high speed circuit breaker. Its work is based on the comparison of the current strength at the input and output of the protected object. That is, the current flowing in the phase and neutral wires must have the same value with a single-phase connection.

If you have three phases, then the sum of the currents in the three phases is equal to the sum of the neutral wire currents. If the indicators have a different value, then this means that there is a leakage current in the circuit.

Current sensors used in RCDs are made on current transformers built on toroidal cores. Threshold protective elements of operation are manufactured mainly on a magnetoelectric relay with high sensitivity.

Although, recently, residual current devices made using special electronic circuits are gaining popularity. Such a circuit activates a protective spring mechanism that breaks the electrical contacts of the circuit in the event of emergency situations.

Connection methods in a private house and apartment

Having decided to put an RCD in your apartment and house, first of all, you need to choose its parameters correctly. First of all, pay attention to the current load, and for what purposes the device is selected.

If there is a need to protect only one device, for example, a washing machine or, then you can limit yourself to the rated current of the device with a small margin.

In the case of installing the device on the entire apartment or house, it is necessary to sum up the value of all loads, and select the appropriate value. The second value will be the differential current, upon reaching which, the protection will operate. After the choice has been made, one thing remains - to correctly connect the RCD.

Phase line connection:

As can be seen from the figure, the RCD is installed after the input machine and the electricity meter. After, the RCD phase wire goes to controlling different load groups. Further, after the switches, it is bred to lighting fixtures and sockets.

Along the neutral line, the wire goes to the terminal block, after it, it is routed to consumer devices.

This circuit does not have a zero bus, which is typical for old apartments and houses. In such cases, a scheme using several RCDs to protect individual consumers may be better suited.

Connection to a single-phase network of single-pole and four-pole RCDs

Four-pole RCD in a single-phase network

In fact, the principle of connecting a single-pole RCD is shown in the diagram above. It is the most common for a single-phase circuit. Using it as an example, you can safely do the installation in your apartment or country house.

The main thing is not to confuse the places of connection of the phase and neutral wires. Usually, for the incoming phase wire, designation 1 is used on the case, for the outgoing phase wire, designation 2. The designation N is used to designate the neutral wire.

The use of a four-pole RCD in a single-phase circuit is, in most cases, unprofitable. It can be used as a temporary replacement, or when a three-phase upgrade is expected soon.

Further, by analogy with a single-pole connection. We connect the neutral wire to the terminal with the designation N. It is desirable to connect the phase to the terminal in the circuit, which includes the Test button. In most cases, it is located next to the zero circuit. It is advisable to carry out a check using the button at least once a month.

Installation location

Usually, the installation location of the RCD in the electrical panel. It contains various devices for accounting and distribution of electrical energy up to 1000 V. In the electrical panel, along with the RCD, automatic switches, an electric meter, distribution terminal blocks, and other electrical appliances are installed.

If you have an electrical panel installed, then you will need a minimum set of electricians to install a residual current device. It will include pliers, side cutters, a set of screwdrivers, a marker.

In rare cases, a set of socket wrenches may be required and the RCD is mounted on a DIN block. If there is no space on the existing block, then you will need to install an additional one.

How to connect RCD and machines?

2 way switch

Walkthrough:

1. Modern electrical appliances have a modular design. For their installation, special mounting . Their use makes the installation process much easier. Switches, residual current devices and many other equipment have a mount for installation on such a rail.
2. Next, we place all the necessary devices and parts at the attachment points in the electrical panel. After that, guided by the PUE, we connect the devices according to the diagram.
3. At the input of electricity to the shield, there must be a two-way circuit breaker. Its main task is to protect the electric meter from short circuits, overload, and make it possible to carry out work on replacing equipment.
4. The input machine also serves as a limiter for the maximum power consumption of an apartment or house. Its rating is selected according to the maximum allowed value of power consumption. Mount the input machine on the top DIN rail.
5. After input circuit breaker, connect an electric meter. To connect the meter, unscrew the sealing screw and remove the bottom cover. Below it will be a group of contacts. Usually, the connection diagram is located on the inside of the cover. If it is not there, look in the instructions for the device. Electric meter contacts have two clamping screws for each connected wire. Their task is to provide reliable contact. After connection, the meter is sealed, and there will be no access to contacts.
6. In most meters, the supply phase comes to the first contact. The outgoing phase is connected to the second. To the third incoming zero wire. To the fourth outgoing neutral wire.
7. After the counter, connect the RCD. The contacts on the device are usually labeled. The input voltage is applied to the top contacts. Accordingly, contacts are connected from the bottom of the device that will go to subsequent circuit breakers and other devices. In this case, polarity must be observed. A phase should come to the phase contact, not zero.
8. After the installation is completed, it is necessary to check the RCD for operability. For this purpose, there is a Test button on the instrument. When pressed, the leakage current is simulated. The device should work by turning off the voltage supply.

Possible errors and their consequences

Most errors occur at the installation stage, especially if it is done by non-professionals:

1. Incorrect connection of supply contacts. Often, zero is confused with phase.
2. Supply voltage from the bottom of the device. With these errors, the device may fail.
3. Zero outputs of several devices must not be interconnected. As a result, the device will lose its sensitivity and will not be able to respond correctly when dangerous situations occur.
4. Also, it should be remembered that it is unacceptable to connect the neutral wire to ground in sockets. This will also lead to malfunctions.
5. You can not make power contacts from different sides of the device, for example, the supply phase from below, and the supply zero from above. The device will not work properly.

If you plan to install one device, then put it right after the electric meter. The problem in this case will be a complete de-energization of the apartment, in the event of a current leakage. Electricity will not work until the leak is repaired.

If you have many different electricity consumption zones, install several devices. This will help you narrow down the troubleshooting area, and provide comfort in other areas.

It should be noted that the installation of such devices in the fire and other alarm circuits is prohibited by safety rules.

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