Basic connection principles
To connect the RCD in the shield, two conductors are needed. According to the first of them, the current flows to the load, and according to the second, it leaves the consumer along the external circuit.
As soon as current leakage occurs, a difference appears between its values at the input and output. When the result exceeds the set value, the RCD trips in emergency mode, thereby protecting the entire apartment line.
Residual current devices are negatively affected by short circuit (short circuit) and voltage drops, so they themselves need to be covered. The problem is solved by including automata in the circuit.
The RCD has a ring-shaped core with two windings. The windings are identical in their electrical and physical characteristics.
The current that feeds electrical appliances flows through one of the core windings in one direction. It has a different direction in the second winding after passing through them.
Self-execution of work on the installation of protection devices involves the use of schemes.Both modular RCDs and automatic devices for them are installed in the shield.
Before starting installation, you need to solve the following questions:
- how many RCDs should be installed;
- where they should be in the diagram;
- how to connect so that the RCD works correctly.
The wiring rule states that all connections in a single-phase network must enter the connected devices from top to bottom.
Professional electricians explain this by the fact that if you start them from below, then the efficiency of the vast majority of machines will decrease by a quarter. In addition, the master working in the switchboard will not have to further understand the circuit.
RCDs designed for installation on separate lines and having small ratings cannot be mounted on a common network. If this rule is not observed, both the likelihood of leaks and short circuits will increase.
Types of RCDs and technical characteristics
The main share of circuit solutions for the domestic sector is precisely single-phase wiring, where, in principle, there are only two lines: phase and zero. The scheme required for the correct connection of such a system in practice is as follows: Work always begins with the installation of a circuit breaker, for example, a 40A model is taken, the maximum load level that it can withstand is 8.8 kW.
Knowledge and understanding of the correct connection of the RCD is the key to the normal operation of the entire electrical circuit as a whole. To avoid problems, you need to connect an automatic machine with a rating not exceeding the operating current of the ouzo. Accordingly, contacts are connected from the bottom of the device that will go to subsequent circuit breakers and other devices.
The classic switching option Depending on the technical load of the number of household appliances and the number of rooms, a single complete network or a network consisting of several subnets can be operated in an apartment or house. Leave your comments and ask questions in the block under the article. An exception is the bathroom equipment of apartment buildings, but it must be located so as to prevent splashing water.
In order to carry out this process in a two-phase circuit, it is necessary to adhere to the following algorithm of actions: Before starting work, disconnect the power wire from the phase of the circuit breaker and the neutral conductor of the shield. After the RCD, it is important to connect circuit breakers for various loads with the corresponding tripping current. The protection will work again when you try to turn on the circuit breaker on the faulty line. It should be remembered that in no case should the zeros of different groups from different residual current devices be connected to each other.
Purpose and scope of RCD
This is a gross mistake and delusion for the following reasons: The principle of operation of the residual current device initially refutes such a version, since grounding does not play any significant role in it. Low-power devices are used at a current of no more than 10 A, and powerful ones - above 40 A. As a final action, it is necessary to bring the conductor to the other three machines, which are also responsible for the socket groups. Intelligible explanations of the author about the operation of RCDs in such conditions and practical demonstrations: At the end of the review material of possible circuit configurations with RCDs, it is necessary to note the relevance of using these devices.
To the input terminal of the device marked N, you must connect the neutral cable, disconnected from the shield body. Before starting work on the connection, it is recommended to draw a basic connection diagram. A common and often used in practice power supply wiring diagram in a private house. The fact is that in these cases, the magnitude of the current is not enough to turn off the circuit breaker, designed to work with overload and short circuit overcurrents.
In any case, the RCD must be connected to increase electrical safety, but this must be done according to the rules. RCD connection diagram in single-phase network without grounding in a private house The home network can be the same as in the apartment, but here the owner has more options. If it is possible to connect the ouzo on each specific network line individually, in the event of an emergency, power will be supplied to a separately taken damaged section. The rest of the wiring will remain energized. The bathroom and sockets are connected to 3 phases using differential machines.
Do I need to install a voltage relay with the device? The principle of constructing an RCD connection diagram For the correct operation of this protective device, in each individual case, the connection diagram to the electrical network should be developed separately. When the difference between them exceeds a predetermined limit, the electrical circuit is broken.
RCD circuit without grounding
We connect without grounding
How to connect RCD correctly
Connecting an RCD in the absence of grounding is done quite often in many apartments and old houses.Since in old-style houses there are usually power cables with one phase and zero, it is not possible to connect grounding. To make grounding, you will need to install a grounding protective circuit around the perimeter of the building, be sure to change all wiring in order to place a new cable with "ground". Only connecting such a core to a special conductor to sockets or separate contacts on powerful household appliances will make it possible to make grounding in an apartment or private house. By combining such protective measures together with an RCD and a circuit breaker, it is possible to provide a residential building with all the necessary measures to prevent accidents.
However, many people simply do not have the opportunity to replace all the wiring in the apartment, since today this is an expensive update. For this reason, an RCD without grounding is installed. Despite the fact that the electrical network does not have grounding, you should not ignore the connection of a residual current device. The protective equipment itself does not have terminals for an earth conductor. It has places for connecting a phase and a working zero. Since this device has a completely different purpose, there is no need for it to make separate ground points.
Wiring diagram for a two-pole RCD
A connected RCD in the absence of grounding is expected to cut off the supply of electricity to the network when the potentials of the incoming and outgoing current change. Therefore, if the house does not have a grounding structure and a three-wire wire is not laid, there is also no reason to refuse to connect other types of protective equipment. It is advisable to install a residual current device and a circuit breaker at the same time.The latter device will prevent a short circuit in an apartment or a private house if the cable is damaged, as well as protect the burnout of household appliances during power surges in the electrical network. From such an RCD, it cannot protect and warn. It is designed to prevent leakage of alternating current in the circuit.
According to the Electrical Installation Rules (PUE), it is impossible to use RCDs that respond to differential current in three-phase circuits for four wires (grounding is combined with working zero). If you install a residual current device on the entire electrical network, then such a scheme will be simpler. When connecting an RCD without grounding, it is imperative to know the parameters of the power cable that is laid in a private house or apartment, as well as the total current strength, calculating the simultaneous connection of all household appliances to the network.
Usually, the installation scheme of protective equipment provides for the series connection of all elements. Even if changes are made to the new schema with the addition of a new source or element, the sequence should not be broken. In this case, it will simply be connected to the appropriate section of the electrical circuit. For single-phase electrical wiring, in which there is no grounding conductor, the residual current device must be placed in front of the switchboard and in front of the power supply meter. Then there are circuit breakers (if there are more than one) and a voltage equalizer. Subject to such a scheme, it is possible to exercise complete control of all wiring in the house, and not its separate branch.
For individual branches with powerful electrical equipment, circuit breakers are installed that will respond to high voltage without turning off the power supply throughout the house. The most common scheme for connecting an RCD is one that is designed for a single-phase power cable with a voltage of 220 volts.
If the owners have a desire to put less powerful protective equipment on each line with powerful equipment, then such a scheme will have a slightly different look. So it is recommended to make connections separately for the bathroom, garage or workshop, cellar, and also for the kitchen. Often there are large studio kitchens, where quite a lot of electrical appliances are connected to the circuit at the same time. In such a situation, it is advisable to divide the residential building and adjacent premises into separate sections with electricity consumption, providing each with independent protection.
Instructions and wiring diagrams for RCDs
In every house, in every city apartment, there is just a huge number of household appliances and appliances that work on electricity. For the normal operation of this equipment, it is necessary to install a special device in the room, the so-called RCD. Otherwise, all equipment will be at immediate risk. In the event that until this time it was not possible to encounter this device, then this article will tell you what an RCD is and how to connect it according to all the rules. But initially it will be necessary to figure out what exactly this device is needed for.
On the The figure shows RCD connection options
Connection rules
It is necessary to install a control device of this type for a number of reasons.First of all, the RCD was designed specifically to protect a person from electric shock. This is especially true when there are real problems in the system. Then it is necessary in order to prevent current leakage. And in the end, the device is designed specifically to prevent fire and ignition of electrical wiring in the event of a short circuit. So, there are at least three reasons why it is impossible to do without this device.
In order to connect a protection device, you must follow a number of specific rules:
- RCD must be connected after the input device.
- In accordance with the norms, “0” and the phase of that electrical circuit, which especially needs additional protection, must pass through it.
- Special technical elements for the installation of RCDs should be used.
Attention! Some are interested: is it possible to connect an RCD without grounding? Experts say that yes, this option is possible. The only thing to remember is the need to create and assemble a circuit according to a certain scheme, which differs significantly from the usual
The only thing to remember is the need to create and assemble a circuit according to a certain scheme, which is significantly different from the usual ones.
How to connect correctly?
In order to connect a protection device in a private house or in a city apartment, it is necessary to take into account the method and type of connection:
how to connect an RCD and machines - according to the rules, you should not connect an RCD in front of the machine, because the device will not be able to function normally in normal mode. Power to the device should be supplied from above;
RCD connection in the shield in the photo
how to connect an RCD in a shield - in this case, the RCD will protect the entire apartment as a whole. This method is the easiest to connect an RCD;
how to connect an RCD without grounding - when connecting an RCD without grounding, you must use the diagram below;
RCD connection without grounding in the picture
how to connect an RCD to a two-wire network - is one of the most common methods for connecting a protection device to an electrical network;
RCD connection in a three-phase network with grounding - in this particular case, there is often no neutral. Only phase electrical cables are used (without the use of winding). There will be an empty zero terminal;
connecting an RCD to an electrical wiring circuit - a protective device is an important element of any electrical wiring system. This will avoid force majeure in the apartment and private house;
In the photo, the connection of the RCD to the wiring circuit
connection of a four-pole RCD - this option is currently the most common. Fundamentally, this option is no different from connecting to a single-phase network. In fact, the number of poles and trunk connections is changing;
RCD for two phases of connection 10 mA - this option involves the operation of a protective device when an electrical leakage of five to ten mA occurs;
connection of an RCD and an automatic circuit 380 V circuit - experts recommend connecting a four-pole type RCD to a circuit with such an indicator.
It should be understood that it is necessary to connect the device only when the shield is turned off.In case of real need, you should purchase one powerful device and install it on the entire apartment building. But it should be understood that this option involves the use of a device with a high level of voltage. To avoid errors and possible problems, you need to attach all the elements in series.
To avoid real problems when connecting, it is necessary to follow a certain schematic arrangement. To do this, use the following embedding schemes for RCDs and abb automata:
Additional wiring diagrams
In some European countries only 2-pole protective devices are used due to their safety regulations. This practice allows you to abandon the additional installation of zero tires: after the machines, conductors immediately follow, phase and zero cables go directly to the devices being serviced.
In Russia, circuit breakers with 1 pole are used, which necessitates the presence of additional zero tires.
The best way to implement them is the following practice:
- Installation of a zero bus directly into the body of the device, which allows you to abandon the abundance of such elements inside the electrical panel.
- Inside one device, you can simultaneously place 2-4 tires, which will be isolated from each other.
- In this case, grounding conductors are brought out and connected to the contact bus, this option is acceptable for most modern grounding systems.
Installation errors
Home craftsmen themselves try to assemble the switchboard, moreover, it is not very difficult if you know all the nuances of the installation process. But they still make mistakes, sometimes very funny ones.Let's look at some of them.
- Do not connect the neutral wire coming out of the tripping device to an open area of the switchboard or electrical installation. In general, do not combine zeros with each other.
- it is impossible to connect the consumer in this way: phase through the RCD, and zero directly, bypassing the protective device. In principle, the device itself will work, only it will turn off all the time. There will be, as they say, a false shutdown.
- Since the article deals with the question of how to connect an RCD without grounding, this option seems to be out of place. But it cannot be bypassed. Some masters connect both zero and ground to the outlet in one terminal. This cannot be done. In this case, the RCD with grounding will operate constantly. Namely: as soon as the socket starts working under load.
- It is impossible to connect groups of consumers with a jumper from zero if a separate RCD is connected to each group.
- It is impossible to connect to the consumer the phase coming from the device from below, and the zero coming from above. Everything should go in parallel from top to bottom.
- The phase circuit is connected to the terminal with the designation "L", zero with the designation "N".
