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August 12, 2017 18:06

RCD .We investigated what RCD how to connect .RCD Wiring Diagrams

circuit - connection - uzoch RCD - residual current device, which serves to protect people from the impact of current.It is also used as a protection against fire, leakage current.RCD in an apartment, office, in a private home, in the workplace and production - one of guarantee that you and your colleagues, pets and other people not to kill the shock.

What is the RCD, and how does it work?For clarity, we give a vivid example.Everyone has a home appliances, which is wholly or partly composed of different metals or a metal part.There are times when there is a dangerous probability of getting an electric shock from these metal parts.For example punched heater PETN, or your child why something has got his fingers in the socket.In this situation, just us and the RCD comes in handy in the apartment, which opens the contact and will not allow you to receive an electric shock, which often turns into a severe injury or death.

RCD is triggered on the basis of the leakage current measurement.If it comes same amount of current as

gone - RCD works.When leakage current device is disconnected.RCD in the apartment - a guarantee of your safety from accidental electric shock.

Differences between RCDs of Emergency circuit breakers.Video

Classification RCD

Consider several types of RCDs.Knowledge of classification will help to correctly answer the question "How to make a connection RCD?".


This capacitive RCD having the highest sensitivity, which are performed on a lightning operation.They work on the principle of capacitive switch that is responsive to the capacitive current.A disadvantage of such RCDs is the presence of electromagnetic interference.


differential RCD operate on the principle of current measurement gone and come.If the currents are equal, the RCD in the apartment works fine, but if the currents do not become equal, that is, there was a leakage current - the device turns off.


This option differential devices - mechanical.The most common type of RCD, developed back in the 80s of the last century.The principle of operation remains the same, changing only the exterior of the device with the years.Prefix DM removed, and now writes and speaks only the RCD.The principle of operation of the RCD is as follows.When the current changes and the magnetic flux, which leads to the secondary winding electromotive force (EMF on in physics textbooks).In this case, the electromagnet pulls the latch mechanism, contactor and the equipment is switched off.With the creation of the electromechanical RCD an opportunity to combine the current limiter and the RCD.


electronic device tripping.Located RCD is usually in rosettes.It is characterized by high sensitivity and triggering lightning.This is a really modern equipment, which does not cause problems on how to properly connect the RCD.The disadvantages is the price and the fact that it is still electronics, and therefore, may not work during voltage dips.

importance indices RCD

Driving RCD connection

Wiring RCD

Depending on the premises and places where you have to connect such equipment, choosing different RCD.A fundamental factor in the selection are the primary and secondary indexes.When you connect the RCD in a private home or apartment should consider indexing system devices.

major indexes RCD

  • AC.Trigger when the unbalance of about 100 mA AC component.The optimum ratio "price-quality."
  • A. RCD protection at 30 mA imbalance.There are false alarms / failure in a TN-C system, and the system TN-C-S may occur in poor grounding.
  • B. They react to leakage currents of any kind.

Additional indexes

  • S. The response time of the device - from five thousandths of a second to one second.It is used in power supply of industrial facilities.
  • G. It is fast and ultrafast RCD used in kindergartens, hospitals, and educational institutions - that is, where security is particularly important in relation to accidental electric shock.

How to select the RCD

How to select the RCD?One of the issues of concern to many people who have decided to make the installation to protect people from electric shock.In order to select the RCD, which is ideal, it is necessary to know the rated current;Leakage current, which is 30-100 mA;choose the value of the cut-off in case of overload, and, finally, to decide what to put. The choice in this case is limited to Emergency circuit breakers or separate RCD.If you live in an old house, where the two-wire network is present, Emergency circuit breakers you can not deliver.If a three-wire power network system, it can be supplied as Emergency circuit breakers, RCD and separately, if the machine is already.

Connection Errors RCD

How to connect the RCD and calculate congestion?

How to connect the RCD, so you do not grieve over the problems that can arise from improper connections, you will learn here today.

To do this we need to find in the data sheet homes or apartments maximum current consumption, and multiply that number by 1.25.

Assume the maximum current of 16A.Multiply by 1.25, we obtain 20A.Rated current RCD take higher than the current cut-off machine.In our case, with a current of 20A, 25A, take a nominal current of the RCD.

Connecting the RCD in the apartment or device to connect to a private house, in the country, in the cottage can be done with the help of a specialist, or to try their own hands and minds.It is important to the strict observance of safety rules.

How to connect the RCD.Video instruction

Wiring RCD distinctive for each power supply.Often it is in the vicinity of a source of electricity.Protective devices can be installed as a single, that is, to all lines is one of RCD, and the RCD each line separately.In the first case, when the protection is activated the system will be difficult to find the cause of this trip.Maybe including current chasm in the entire apartment.In the second case we will immediately show what RCD worked, and the reason will be easier to find.The only negative would be to the dimensions of the switch box.It's too big and can take up a lot of space.

Wiring RCD and machines.A photo

Wiring RCD and machines.Photo

Wiring RCD tells us that the power comes on the opening machine 50 A, with the machine on the power meter to meter both wires - phase and zero - go to the RCD-63A.With protective devices live wire goes to the machines, which will connect the outlet.For example, with zero RCD goes to the terminal block is the zero N.

Wiring three-phase RCD .A photo

Wiring three-phase RCD.Photo

If you realize that you are able to independently carry out a connection RCD, follow some of the recommendations.The important point is to connect wires to the terminals of the RCD.Do not confuse the terminals and wires, so as not to complete the circuit and not to spoil the device.
If you are faced with the choice of how much to put the RCD, then figure out how much space can be dangerous for you and your loved ones with regard to electrical safety.If the financial capacity allows, you can even put on each outlet separate RCD.However, it is impractical, as many sockets are rarely subjected to the connection and disconnection of devices.Typically, devices included in the network, and there are - TV, desktop PC, and more.Select only those outlets and premises where there may be electrical shock.This will save space in the electrical panel and your money.

How do I check on the efficiency of the RCD

RCD without grounding

RCD without protective put and works just as well as grounding.Its properties are not changed, it also works as the RCD, which works with the ground.RCD disconnects without grounding is through leakage current conductors, which may be as a person, as a conductive object.In this case, you choose how to select the RCD connection with earth, or without.

Taking into account all the nuances of the RCD installed in a private home and apartment, you can summarize and sketch a rough plan of how to connect the RCD better and more economical.This is a complex of diverse works, it is important to do the preparatory part of the job - to choose which device you'd better fit, and then call a specialist.If skills in electrical allow for RCD yourself, it is best to read about it as much information as possible.Finally, when the residual current device is found, you will be confident in the safety of your family from accidental electric shock.