Connecting the RCD: how + schemes and connectivity options

Creation of a modern power inside apartment - responsible action associated with the calculations, choice of wires and electrical installations, installation works. In this case, one of the main tasks is to ensure the safety of occupants and property. Do you agree?

If properly selected protective devices and wiring diagram are thought RCD and machines, all risks are reduced to a minimum. But how to do that? What to consider when choosing? These and many other questions we will answer in our material.

Also you will be able to understand the operating principle of the RCD and circuit variants. Expert advice and installation of the nuances collected in this material. In addition, the article posted videos of which you will learn about the major mistakes when connecting, and see how to connect the RCD in practice.

The content of the article:

  • Appointment and operation of the RCD
  • protection options for a single-phase network
    • Option # 1 - general RCDs for 1-phase mains.
    • Embodiment # 2 - total RCD for a 1-phase network + counter.
    • Option # 3 - general RCDs for 1-phase mains + group RCD.
    • Option # 4 - 1-phase network + group RCD.
  • Schemes for 3-phase networks
    • Option # 1 - general RCDs for 3-phase networks + group RCD.
    • Embodiment # 2 - total RCD for three-phase networks + counter.
  • Installation instructions RCD
  • What mistakes should be avoided?
  • Safety rules during operation
  • Conclusions and useful videos on the topic

Appointment and operation of the RCD

Unlike machine which protects the network against overloads and short circuits, intended for RCD instant recognition of leakage current and respond by disabling the network or separate electric line.

Since these two different functional protective device, both must be present in the assembly scheme.

The principle of operation is simple RCD: comparing magnitudes of incoming and outgoing current and operate at a mismatch is detected.

Scheme tripping RCDs

A diagram showing operation of the device if there is a breakdown phase. First voltage relay (CR), then contactor (K)

Inside the housing of the automatic device is a transformer with core and windings with uniform magnetic flux directed in different directions.

When an output of the magnetic flux leakage is reduced, whereby the relay and opens the power is activated. This is possible if a person touches a grounded device and the electrical circuit. On average, it takes 0.2 to 0.4 seconds. Read more about the device and the principle of action RCD we are talking about here.

There are different types of devices, designed for networks with direct or alternating current. One of the most important technical characteristics, which is necessarily present in the marking - the power of the leakage current.

choose the device nominal value of 30 mA to protect the occupants of the house. Where there is an increased risk of, for example, bathrooms with high humidity, game room for children, set the RCD is 10 mA.

Higher denomination, e.g., 100 mA or 300 mA is designed to prevent a fire because large leakage current can cause a fire. Such devices are assembled as a common introductory RCD, as well as businesses and large objects.

Detailed information on choosing a suitable RCD I set out in this article.

Compare RCD and Emergency circuit breakers

RCD (left) should not be confused with Emergency circuit breakers (on the right), which combines the functions of automatic switches and circuit breakers, ie it can operate as an overload, and on leakage

RCBOs compact bundle of protective devices and takes up less space in the control cabinet, but it triggered more difficult to find the cause of the shutdown.

Fitting scheme is selected in accordance with the task and view the network - 1-phase or 3-phase. If you want to protect a house or flat from the current leaks, RCD installed on the power line input.

protection options for a single-phase network

On the necessity of mounting a set of protective equipment manufacturers mention powerful appliances. Often in the literature accompanying the stiralka, electric stove, dishwasher or boiler Specified which devices must be installed in the network.

RCD in the electrical distribution

Increasingly, however, use multiple devices - for individual circuits or groups. In this case, the device in conjunction with a machine (-th) is mounted in a cabinet and connected with a particular line

Given the number of different circuits serving sockets, switches, technique, the maximum loads the network, it can be said that connecting circuits RCD infinite. In a domestic environment, you can even set outlet with built-in RCD.

Next, consider the popular connectivity options which are basic.

Option # 1 - general RCDs for 1-phase mains.

Place the RCD - on the power lines entering the apartment (house). It is mounted between the common two-pole machine and a set of machines to service various power lines - lighting circuits and sockets, separate branches for household appliances and others.

Total RCD for a 1-phase network

If any of the off-elektrokonturov there leakage current protection device immediately disconnect all lines. This, of course, its disadvantage, since it is impossible to pinpoint exactly where the problem

Assume that the current leaked from contact between the phase conductor with plugged in metal fittings. RCD is triggered, the system voltage is lost, turn off and find the cause will be difficult.

As for the positive side of the economy: one device is cheaper, and place in a cabinet takes up less.

Embodiment # 2 - total RCD for a 1-phase network + counter.

A distinctive feature of the circuit is the presence of electricity metering device, which installation is required.

Protection from leakage current also connected to the vending machines, but incoming line counter coupled thereto.

Total RCD for 1-phase mains electricity meter +

If you want to cut off the electricity to the apartment or house, disconnect the overall machine, not the RCD, although they are mounted side by side and serve the same network

The advantages of this arrangement are the same as that of the previous solutions - saving space on the electrical and money. The disadvantage - the complexity of the current detection of the leak.

Option # 3 - general RCDs for 1-phase mains + group RCD.

The scheme is one of the complicated species previous embodiment.

By installing additional devices on each work path protection against leakage currents becomes double. From a safety point of view - this is a great option.

Total RCD for a 1-phase network group RCD +

Suppose the crash leakage current and RCD circuit connected lighting for some reason did not work. Then react the overall device and disable all lines already

To just did not work both devices (private and common), you must comply with the selectivity, that is, when you install and take into account the response time, and the current characteristics of devices.

Positive side circuit - one circuit disconnected in an emergency. Very rarely occur cases where the entire network is turned off.

This can occur if installed on a particular line of RCD:

  • defective;
  • out of order;
  • It does not match the load.

To similar situations do not arise, be sure to check with RCD test methods on the performance.

Cons - load switch board number of similar devices and additional expenses.

Option # 4 - 1-phase network + group RCD.

Practice has shown that the scheme without mounting general also good RCD functions.

Of course, insurance against failure of one no protection, but this is easily remedied by buying a more expensive device from the manufacturer you can trust.

1-phase network group RCD +

Scheme embodiment resembles to the general protection, but without setting the RCD on every single group. Characterized by important positive aspect - it is easier to identify the source of the leak

In terms of savings, electrical multiple units loses - a total cost would be much cheaper.

If your flat mains is not grounded, be sure to check with the schemes connect the RCD without grounding.

Schemes for 3-phase networks

In homes, industrial buildings and other facilities can meet different version of power supply arrangement.

So, for the apartments 3-phase mains connection is not typical, but to equip a private home that option is not uncommon. It will be used to connect other circuit protection device.

Option # 1 - general RCDs for 3-phase networks + group RCD.

For network 380, 2-pole device is small, requires a 4-pole analogue: it is necessary to connect a zero conductor 1 and 3 phase.

Total RCD for three-phase networks + group RCD

Scheme complicated equipment electroline each individual device RCD. It optionally, but duplexed protection recommended for additional protection from leakage currents

Important form of wires. For 1-phase network suitable standard cable VVG, while for 3-phase recommended stretching more resistant to fire VVGng. On the choice of a suitable type of wire we wrote our other article.

Embodiment # 2 - total RCD for three-phase networks + counter.

It repeats the previous solution, but in the scheme of added energy meter. RCD group are also included in individual line service system.

Total RCD for three-phase networks counter +

Of all the circuits this is the volume in the literal sense, that is, it requires the installation of a large switchboard with a lot of wires and connected appliances

There is a caveat, which refers to any of the presented schemes. If the apartment or house several lighting and socket circuits, a number of powerful domestic devices that require a separate electrical arrangement, it makes sense to install with double protection general RCD.

In the opposite case it is sufficient or common unit, or one for each circuit.

Installation instructions RCD

First you need to choose a location for mounting the device. Apply 2 options: a shield or enclosure. The first resembles a metal box without a lid, mounted at a height convenient for maintenance.

Cabinet is equipped with a door that can be closed on the lock. Some types of cabinets have holes so that you can remove the meter readings are not throwing open a special door and turn off the device.

Machines and the RCD on the DIN rail

Protective devices are fixed on mounting DIN-rail arranged horizontally. The modular machine design, Emergency circuit breakers and RCD allows one to place on the rail a few pieces

To the left terminals on the input and output always connect the neutral wire to the right - phase. One of the options:

  • input terminal N (top left) - by opening the machine;
  • yield N (lower left) - a separate zero bus;
  • input terminal L (upper right) - by opening the machine;
  • output L (lower right) - to group machines.

At the time of installation of the protective device on the shield already breakers can be installed. To streamline the arrangement of devices and wires may have to rearrange the devices in a specific order.

Introducing setting example of introductory RCD enclosure, where there is a counter, and the automatic opening of circuit breakers for several individual circuits - lighting, etc. rosette.

image gallery

Photo of

Metal switchboard brand IEK

shield Dimensions (SHUE, SCHUE, Wp) depend on the number of devices placed inside. Better to choose a product with a small margin for the installation of new machines and the RCD

Set of protective devices before installing the RCD

DIN-rail in one row, previously set (left to right) a home appliance electricity metering, then opening the switch and one of group 5 automata

Selecting a location for the installation of RCDs

The best solution for the installation, a reasonable work devices - located between the introductory machine and other devices serving a single line (rosette et al.)

How to connect the wires to the device

From the lower left terminal phase conductor extends to the upper secondary terminal of the automaton, and zero - to the ground bus, which is located below. Outer phase - from the opening machine, zero - the counter

Metal switchboard brand IEK

Metal switchboard brand IEK

Set of protective devices before installing the RCD

Set of protective devices before installing the RCD

Selecting a location for the installation of RCDs

Selecting a location for the installation of RCDs

How to connect the wires to the device

How to connect the wires to the device

Never connect the RCD at the entrance - it always follows the general introductory circuit breaker. If the counter is used, the residual current device moves to the third position from the entrance.

Description of the connection process:

  • install the device on DIN-rail to the right of the machine - enough to make it and push with slight pressure until it clicks;
  • stretch cutting and bare wires of the machine and zero tire inserted into the upper terminals according to the scheme, spin fixing screws;
  • in the same way we insert the wire into the lower terminals and tighten screws;
  • test - first includes a general machine, then the RCD, press the button "Test"; when you press the instrument must be disconnected.

To ensure proper connection, sometimes portray the leakage current. Take two working wires - "phase" and "earth", at the same time is supplied to the cap bulbs. A leak, and the device should work immediately.

What mistakes should be avoided?

Before connecting Be sure to double-check the specifications of the hardware. Current Rating must be equal to or higher than the similar parameter at the input automaton. Determine the value of easy labeling.

Electricians recommend choosing the protective device on the step above, that is for the machine to fit 50A RCD 63A.

parameters can be calculated correctly, select machine and RCD best nominal value, but during assembly to allow a small error, whereby the system is useless.

For example, beginners are often confused tire. Keep in mind that for the neutral conductor and the ground wire using different tires. Additionally, each device requires a separate bus: 5 RCD - 5 tires.

Wire the RCD

Whatever the connection scheme you use, the ground wire it will not participate. All terminals are designed either for the phase conductor (load) or to zero (neutral)

In no event should not be confused pole N and L. They have to lettering housing and wires differ in color, so you must be careful.

If there is a false positive or, alternatively, the device does not respond, it may be because of the following:

  • "Phase" and "earth" connected after RCD;
  • incomplete connection - N conductor is not inserted into the corresponding terminal;
  • "Zero" and "ground" are connected in the receptacle;
  • confusion between two or more connecting RCD to installations.

For errors in practice far more, because different schemes are used. The more devices involved in the assembly of the electrical panel, so you need to be more attentive when connected.

Safety rules during operation

Most of the rules of a general nature, ie they should be used in any electrical work.

If you decide to equip their own distribution switchboard before you install and connect the RCD, make sure to:

  • disconnect the power supply - turn off the machine at the entrance;
  • use the wires with the corresponding color-coded;
  • do not use metal pipes or fittings in the apartment to the ground;
  • first of all to establish the automatic input switch.

If it is possible, it is recommended to use separate devices for lighting lines, sockets, circuit for a washing machine and others. In the opposite case it is sufficient installation general RCD.

The groups with RCD

To protect children from all electrical child's room are usually combined in one circuit and equipped with a separate device. Instead, the RCD can use Emergency circuit breakers

Further characteristics of the devices themselves, are important parameters and other electrical elements, e.g., electricity cable cross-section. It should be calculated taking into account a constant load.

Connect the wires to each other better by means of terminals, and to connect to devices - use a specially designed, labeled terminals, as well as on the housing scheme.

Conclusions and useful videos on the topic

A few practical tips and explanations will help beginners understand how to select and connect the RCD in the house or apartment.

Error when connecting sockets:

On the necessity and the nuances of the installation of protective devices:

Not always it is possible to call a qualified technician to the electrical distribution equipment. Sometimes machines or RCD has to be installed on their own.

Due to an oversight when installing an electric shock may occur, so it is important to use a wiring diagram, do the calculations right and follow the safety rules.

Professionally engaged in electrical works and want to add tips, or other connections RCD? You may want to supplement our article recommendations on electrical safety? Write your comments in the box below - your comments will be useful to many domestic masters.

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