How to connect the difavtomat correctly?

Appointment differential automaton consists of three main functions: protection against short circuit, current leakage and overvoltage of the power supply network. As you know, this device is a combination of an RCD and a circuit breaker in one case. Next, we'll talk about how to install and connect the difavtomat with your own hands!

Choose a way

To begin with, we will deal with the main options for electrical work, as home wiring can be single-phase (220 V), three-phase (380 V), with and without grounding. In addition, the product can be installed only on the introductory panel in the apartment or on each individual group of wires. Depending on these conditions, the connection scheme of the difavtomat can be slightly modified, and the device itself will have a different design (bipolar or four-pole).Bipolar model

So, let’s take a look at each of the ways to connect the difavtomat in the shield.

Simplest protection

The easiest installation method is one introductory difavtomat serving all apartment wiring. In this case, you need to buy a powerful device designed for the current load from all electrical appliances in the room. The disadvantage of such a connection scheme is that if the protection works, it will be problematic to find the problem zone yourself, because breakdown can be anywhere.Circuit with introductory protective device

Please note that the ground wire passes separately, connecting to the grounding bus, to which all PE conductors from electrical appliances are connected. Another important point is to connect the neutral conductor. Zero, which is derived from a differential automaton, is strictly forbidden to connect to other zeros of the mains. This is due to the fact that different currents will pass through all the zeros, which will cause the device to operate.

Reliable protection

An improved option for connecting a difavtomat in the house is the following diagram:Separate service for each group

As you can see, for each group of wires, a separate device is installed, which will work only if a dangerous situation arises in his “section”. At the same time, the rest of the products will not react and will work in their normal mode. The advantage of this connection option is that when leakage current, short circuit or power congestion You can immediately find the problem area and proceed to repair it. The disadvantage of this method of installing a difavtomat is the increased material costs for the purchase of several devices.

Without grounding

Above, we provided several examples in which a ground contact was present. However, in the country house and in old houses (and, accordingly, with the old wiring), a two-wire network was used - phase and zero.

In this case, the connection of the difavtomat was carried out according to the following principle:Option without PE protection

If in your case there is also no “land”, be sure to home wiring replacement to a new, more secure one.

In a three-phase network

If you decide to install a difavtomat in a cottage, garage or a modern apartment where a three-phase 380V network is used, in this case it is necessary to use a 3-phase automatic machine. In fact, the circuit will not differ from the previous ones, if you do not take into account the fact that four wires must be connected at the input and output from the housing.Three-phase device for 380 V network

The diagram shows how to connect a three-phase difavtomat to the network:

Three-phase network protection circuit

So we have provided the existing ways to connect a differential machine with our own hands. The most correct option is one that is with grounding and several separately installed devices.

We also recommend that you watch a visual video instruction with the correct connection of wires:

Selective circuit

Install the product

After you decide on the connection method, you need to proceed to the equally important stage - installation work. In fact, installing a differential machine is not difficult, the main thing is to do everything correctly and according to the instructions. To readersmy.electricianexp»Were able to quickly and easily install a difavtomat in the shield, we provide the following step-by-step instructions:

  1. Inspect the housing for defects and mechanical damage. Any crack in the case may cause the product to malfunction.Housing without damage
  2. Turn off the electricity in the house and make sure that there is no mains voltage using an indicator screwdriver (or a multimeter). About, how to check the voltage at the outlet, we told in the corresponding article!Power outage on the shield
  3. Install the difavtomat on the DIN rail as shown in the photo.DIN rail mount
  4. Strip the insulation on the connecting cores, for this it is recommended to use stripping toolwhich will not damage the live contact.Stripping insulation with side cutters
  5. Connect the phase and neutral conductors, according to the diagram, to the special connectors on the body of the difavtomat. We draw your attention to the fact that the lead wires must be attached from above.Opened lead cores
  6. Turn on the power and check if the device is working.

That's the whole technology of installing a differential automaton. We recommend using products only from well-known manufacturers: Legrand (legrand), ABB, IEK and Dekraft (decraft).

We also advise you to familiarize yourself with the connection errors that we provided below.

Basic connection errors

As we already said, if the difavtomat is not properly connected to the network, problems such as its false operation or even a complete failure can occur.

The following connection errors may be responsible for the faults:

  1. The zero wire at the output of the housing is connected to the remaining zeros. As mentioned earlier, passing currents will provoke the device to false operation.
  2. Introductory L and N are wound from the bottom of the case. Such an error occurs very often in practice, indicating the carelessness of the electrician who made the installation. Even on the front panel of the differential automaton a diagram is drawn according to which input is carried out only from above.
  3. Zero connects to the "earth". This option is sometimes used in old houses where a two-wire network is used. The result of an incorrect connection is a false protection.
  4. Wire N is connected directly to the appliance (past protection). In this case, a trip will also occur.
  5. In the circuit there are several differential machines and at the same time the electrical device is connected in phase to one, and zero to the other. The result is a shutdown of one or two protective devices at once.

You can clearly see the errors in the video below:

Incorrect differential machine connection

That's all I wanted to tell you about how to properly install and connect a difavtomat with your own hands.

Related Material:

Selective circuit

Incorrect differential machine connection

(34 votes)
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39 comments

  • Denis

    Good afternoon, please tell me if it makes sense to connect the c16 0.03a differential automaton parallel to the c50 input automaton. The idea is that turning off the opening machine, and turning off all the electrics in the house, the line behind the differential (and this is the refrigerator) will work? In front of the entrance circuit breaker there is another 1 two-pole circuit breaker c62 and a differential circuit breaker with 50 0.1a in the driveway. Thanks in advance.

    To answer
  • savva

    In the photo on installing the difavtomat on the din rail, why does the brown wire (understand L) go to the terminal block?

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    • Admin

      Yes, it’s figuratively done as an example. It is just shown that the introductory L and N go up.

      To answer
  • Alexei

    Please tell me, on 4 automatic machines, 3 by 16 and one 10 amperes, which differential machine should be set, how to calculate which set?

    To answer
    • Admin

      25A 30mA is enough. And yet - it is easier to put diffs and RCDs on each line than one common one, so it will be easier to figure out where the RCD is triggered, on which line.

      To answer
  • Valery

    Hello!
    Difavomat PFL6-16 / 1N / C / 003 "Moeller" does not turn on, i.e. the toggle switch does not lock in the on state. Can I do something with it or buy a new one?
    thank

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  • Eugene

    Thank! Your hint helped to figure out that you can’t connect zero from the differetomat with zeros of consumers who are not connected to this difiltomat.

    To answer
  • Alla

    Please give some advice. The apartment has a 7.7 kW water heater. On the heater line in the apartment there is an RCD 40 A. Outside the apartment there is a three-phase differential power device 25A, 100 mA and RCD.
    The RCD in the entrance some time after turning on the heater is triggered. An electrician suggested changing the differential voltage to 40A, 300 mA. I do not know what section of the wire is laid to the heater. Tell me, is it possible to change the WPPT to the proposed modification? Confuses 300 mA. Thanks in advance.

    To answer
    • Admin

      The wording confuses: “Outside the apartment there is a three-phase differential transformer 25A, 100 mA and RCD.” Maybe just one of them is automatic? Check or give a photo of the devices installed in the entrance.

      To answer
  • Basil

    good evening! Tell me which differential to put on 3 ouzo 25a that go under the sockets in the trading floor of the store?

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    • Admin

      RCD - a device responsive to current leakage. Difavtomat also reacts to leakage currents and short-circuit currents. What is going to put where, it is not clear.

      To answer
  • Andrew

    Is it possible to use difavtomats on groups of automata? Only diphatoms are simple, but there are no simple RCDs. Cost is unimportant, as it’s free. Thank you very much for your articles and videos.

    To answer
  • Marat

    there is a two bedroom apartment, that is, a hall, a bedroom and a kitchen, the idea for each room is to put one differential machine, advise what load should there be differential?

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  • Sergei

    Hello! In the apartment (new building) at the entrance there was a difavtomat 63 A, 100 mA. After replacing the shield by inexperience, I installed a simple automatic machine at 63 A. Do I need to install a difavtomat. On the group of the outlet, a difavtomat is installed. Thank.

    To answer
    • Admin

      Hello! It is advisable to install, a 100 mA difavtomat performs a fire-fighting function, once it has been installed, so it is necessary. But the difavtomat on sockets will just protect against current leaks.

      To answer
      • Sergei

        Fire function in what is expressed?

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        • Sergei

          And the connection scheme is getting complicated?

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        • Admin

          The fire-fighting machine will primarily protect the lead-in cable, as well as those wiring groups that will not be protected by a separate machine. It is also a backup, in case the group differential machine does not work.

          To answer
  • Sergei

    Sorry not a specialist. It was an RCD. BUT SAID that they are not reliable.We recommended ABB, and only automatic machines were available. Are there ABB 63/100 difavtomats? Or 50/100?

    To answer
    • Admin

      There is a 63A / 100mA difavtomat from ABB, bipolar, type AC.

      To answer
  • Sergei

    Recommend reliable.

    To answer
  • Sergei

    What does bipolar mean? I have a single-phase meter.

    To answer
    • Admin

      Bipolar means breaking both phase and zero, it is single-phase.

      To answer
  • Nurek

    Good morning
    What kind of return button how to use

    To answer
  • Vadim

    Is it possible to separate 3-phases. differential automaton AD14 as 3 1-phases. thank.

    To answer
  • Sergei

    Hello! Tell me where to get the zero wire, if the output from the diff can not be connected to the zero common bus ?!
    Thank.

    To answer
    • Sergei

      The zero wire coming out of the opening diffavtomat will be the common zero, or the common bus for all your electrical appliances. This neutral wire of yours cannot be connected to other neutral wires coming out, for example, from other input difattomats.

      To answer
  • Yurich.

    Hello everyone! How to properly ground in an apartment or in your house if it was not there at all? Thanks in advance 😉

    To answer
    • Sergei

      And where are you going to get this grounding from?
      The body of the shield in the corridor is not grounding.
      In a private house, you need to create your own grounding by driving several metal squares of a certain length into the ground. Then these squares are welded together and from here the grounding wire is taken. Which is properly wired to the corresponding terminals of each outlet.

      BUT! Such a ground loop must be done correctly, and it must be tested for resistance to current spreading in an electrical laboratory. And they must give an appropriate test report. That is, initiative and hope for luck in this matter are inappropriate, because they can cost lives.

      To answer
  • Idiah

    Please tell me, when connecting the input to the upper terminals of the 1ph differential automat, it is necessary to observe phasing. The machine indicates a zero, but if you connect without observing this designation, I mean the zero phase, the zero phase. Is this considered a bad connection?

    To answer
    • Admin

      Hello! If phasing is indicated by the manufacturer, then it is imperative to observe it and entangled phases with zero will be considered an erroneous connection.

      To answer
  • Alexei

    Selectivity is Fine, but in the video the AVDT data is not suitable for apartments by the type of differential current!

    TO DETERMINE THE TYPE AVDT (DIFA), IT IS NECESSARY TO KNOW THE TYPE "A" ICON Since it is not written on the case of the Difa, but is Designated in the Rectangle, the type "AC" looks like "~" (like in the video), and the type "A" looks almost the same, BUT UNDER "~" THERE ARE ONE TWO WAVES, i.e. the sign in the double rectangle!

    * The DIF type determines which leakage currents the AVDT (HELL) will control: Type "AC" (sold everywhere) - monitors only alternating current (50 Hz) - not suitable for an apartment!

    Type "A" (harder to find) - controls alternating current (50 Hz) + pulsed DC components (washing machines, computers, switching power supplies, in short - almost all modern equipment) - IT'S FOR AN APARTMENT!

    There are Selective models - namely, type “A” with a letter on the housing “S” (they are placed on fire in the house / apartment with a setting of 100 or 300 mA as fire-prevention), for example IEK AD12MS 2P 25A 100mA, type A.

    But 100 and 300 mA can only be set at the input, and AVDT with a setting for a differential leak of 30 mA is put in the wiring around the apartment (for consumers) (this is shown in the video correctly)!

    But the video is simple, common and unsuitable for modern technology type "AC"! Given the fact that the video was posted in May 2012, we can forgive such a mistake, because earlier there could simply not have been an “A” type, but now they are being sold and APARTMENTS / HOUSES MUST ONLY BE TYPE “A”!

    Light Yes Case

    To answer
  • Alexander

    Alexander, I sent this question to another page of yours, but I'm not sure that it was accepted, so I’m duplicating it. Sorry if that.
    In the instructions for the DSH941R differential machines, enclosed in the box, in Fig. 1, on the right (in the reading orientation), the arrows show the direction of network connection from top to bottom and bottom to top (see file), unlike your recommendation, only from above. Where is the truth?

    To answer
    • Admin

      Hello! If the manufacturer allows the lower connection of the input wires, you can connect.

      To answer
    • Admin

      I’ll add it on my own, then you don’t forget then that you connected the power from below “because you can”, and do not forget to tell the electrician who will later serve. Everyone and everywhere out of habit assume a “top” connection. There is no technical difference, but if you do it differently everywhere, it will be bad. In technology, everything should be similar.

      To answer
  • Sergei

    Hello! If the apartment is RCD 63A at 100ma should I put a differential. automatic machine for a flow-through backup water heater line with an ex. mountain of water (4.5 kW) in the toilet and washing machines in the bathroom? Alone and which one?

    To answer
  • Michael

    What a sorrow, experts connect the phase to the bus, which is used for zero and without protective insulation ....
    Put a total differential up to the PU at the rated load with a leakage current of 100mA (fire) and on all sockets a total of 30mA (except for the electric stove) or separately on the bathroom separate differential machine 10-30mA (who does not want to install the group on sockets)

    To answer

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