Which is better to put: difavtomat or RCD?

If you do not know what is better to choose and put - an RCD or a difavtomat in a private house, then you first need to understand how both devices work and what is their difference. That is why, first of all, we will consider the purpose of the products, after which we will provide our own recommendations for selection.

Residual Current Device, which is often called a differential switch or a differential switch, serves to turn off the electricity in the network when a leakage current occurs. This problem may occur if the cable is damaged. If you do not protect yourself from leakage currents, then a person may be injured by electric current, as well as spontaneous combustion of the wiring (it begins to melt) and, as a result, a short circuit.

ABB Products

Difavtomat - This is an RCD connected to a circuit breaker. The device is used to protect against leakage currents, as well as to prevent overloading the wiring and its damage during a short circuit (the last two functions are the main purpose of circuit breaker).

IEK Product

Summing up, we can say that a differential circuit breaker is, roughly speaking, an RCD + automatic machine. Now let's talk about which device is better to choose when installation of electrical wiring in the house.

Advantages and disadvantages

Having learned the differences between the two devices, the idea immediately arises that it is necessary to choose the second embodiment. This is a hasty conclusion, because if the RCD is additionally protected by a circuit breaker, then, in fact, this will be a differential machine. Therefore, in order to already say for sure that it is better to choose an RCD or a differet machine, it is necessary to determine the advantages and disadvantages of each product.

The advantage of the combined model is that it is compact (does not take up much space in the electrical panel), and also completely protects the wiring from various kinds of dangers. In addition, the cost is slightly less than the purchase of an RCD + machine, and installation is faster (you need to tighten a few screws less).

The main disadvantages are:

  • If the difavtomat fails, it will be necessary to acquire a new one. We immediately draw your attention to the fact that in case of a breakdown of the RCD + automatic combination, only one product will need to be replaced, because extremely rarely two immediately break. Like it or not, a single item will cost less than a combined option.
  • When disconnecting, it is difficult to understand the reason: the occurrence of short circuit, leakage current or network congestion. In the case of shared devices, the reason is much easier to find out: knocked out AV - short circuit or overload, knocked out RCD - current leakage.

The advantages and disadvantages of a separate version can be derived based on the pros and cons of the previous device, namely:

  • buying a new product will be cheaper;
  • it is easier to identify a breakdown;
  • install longer;
  • takes up more space on the DIN rail;
  • lack of protection against short circuit and overload if the circuit breaker is absent.

Well, the last thing I would like to talk about is that it’s better to choose and put it in the house: an RCD or a difavtomat.

Which is better to install?

You familiarized yourself with the purpose, advantages and disadvantages of each device. If you still do not understand the answer, let’s summarize by choice.

If you exercise installation of electrical wiring in the apartment or a house with a simple wiring diagram, it is permissible to install only a difavtomat. When creating a complex network in a cottage, it is better to use several RCDs with AVs for each group of wires (sockets, for lighting, for powerful electrical appliances, etc.). To protect a separate network with low power consumption, a difavtomat can not be installed, but it is enough to secure the line with only a residual current device.

We draw your attention to the fact that the functionality of both options is the same, so you can not give preference to one of the devices based on its performance!

Video instruction

To your attention a video on which the difference is clearly explained:

Key product differences

That was all I wanted to tell you about the two protective devices. We hope that now you know for sure that it is better to choose an RCD or a difavtomat for a private house and apartment.

Also read:

Key product differences

(18 votes)


  • Sergei

    Thanks for your articles, very informative for beginners!
    I had a question regarding the first circuit (automatic + RCD) - What will happen if they are interchanged? Those. First, Uzo stands, and behind him an automatic machine ... I collect wiring in the house myself and decided to hang several lighting groups on 1 UZO, respectively, for each lighting group there will be a separate automatic machine. Is it correct? And also, please tell me how to simulate a phase touching a person? (How to test a leak?)

    To answer
    • Admin

      Hello! It will be the right decision to first install an RCD, and then connect the machines to each lighting group. Thus, the circuit breakers will protect the RCD in the event of a short circuit. You can test current leakage using the special “test” button. Press it and the RCD should work.

      To answer
  • nicholas

    good afternoon! in the video about errors connecting difavtomatov when connecting the load triggered
    shaft and AUTOMAT IUZO. but as you said, it is a difavtomat KURSK production and IT
    WORKS AS SEPARATE DIPHAVES and RCD.That is, you can determine the direction of the search.
    for reference. And if such a response is then it is unequivocal that the WRONG CONNECTION
    NIE? Please illuminate. For your work, THANKS.

    To answer
  • Volodya

    From the first, power is supplied to the UZO-25A, and from the UZO, the AV-16A is powered. Or, depending on the expected load, the UZO-32A AV-25A. The response time AND the sensitivity of the leakage current of the RCD are the same, for which the AB is protected at short circuit

    To answer
  • Sergei

    Hello. In the apartment there is a differential at the entrance of C50. then 3 automatic machines. I began to turn off often. Can I replace the C50 diff by 63?

    To answer
  • Sergei

    It is worth it now

    To answer
  • Boris

    and this and that garbage, put Schneider or abb and forget. Well, yes, it may not be at all in the machine ..

    To answer
  • Rishat

    Hello, do you need a soft start in the apartment so that when the air conditioner is turned on, there is no margal light

    To answer
  • Shoma

    A very cool site, but I want to conduct sockets and switches in a private house myself, there are a few skills, but I'm not a master electrician, so I want to assemble a shield with machine guns and draw wires to it. Anyway, I need the help of a professional in collecting the shield, well, ask for details before connecting to the house. I just love the electrician, I don’t know why, but I do it with great pleasure.I haven’t studied where but I can conduct electrical switches, and there is only one problem that I can’t understand how to connect wires to a double switch or connect wires from a switch to a distribution box.

    To answer

Add a comment

Required fields are marked *