Which circuit breaker to use 4P or 3P?

Hello
I have a similar dilemma when choosing a switch, how many people have so many sentences.
As I already have a 4P switch and to reconcile both methods without buying 3 + N, add a 3P switch at the cost of 3 fields and PLN 35. What do you think about such a scheme? I know, I know now it will be unnecessary for both groups but maybe a compromise because I don't know who to listen to anymore ;)

Complete electrical nonsense.

So I have to rely on an electrician, depending on his preferences, I will have a 3P or 4P switch. I have already talked to the 4th and the opinions are divided, of course I did not find a solution on the forum either.

I am of the same opinion as my friend @ Lukasz-O , overgrowth of form over content, loss of 3 fields and no benefit.
\ edit.
In my opinion, track N should not be interrupted (unless only 3P + N).

For what purpose do you want to add a 3p switch?
You can see that you completely misunderstood why the 4P switch is not a good solution and what is the difference between 4P and 3 + N.
A senselessly added 3p will not improve what can spoil 4p.

First of all, decide what the network layout is. N enters the disconnector and then it becomes PEN. What is this freak?

Do not forget colleagues that the network layout is confused here.
Well, a friend of mine beat me

The network is written TN-C and what you are asking is probably a PEN chapter.
Illustrative drawing a bit badly drawn.

OK thanks for the comments, i.e. the greater majority is behind the 3P switch. The network is TN-C.

masonry wrote:

You can see that you completely misunderstood why the 4P switch is not a good solution and what is the difference between 4P and 3 + N.
A senselessly added 3p will not improve what can spoil 4p.

From what I have read, I understand that 3 + N has "priority" N. Supporters of 4P want to disconnect WLZ entirely and supporters of 3P not disconnect N. So using 2 switches, 4P will turn off all or turn on L to 3P and N to PEN, of course, 3P must be turned off. It is only through 3P that we supply L power. All the time, 3P does not give anything in this diagram, so it depends on who is looking at it, 3P would be the main switch and 4P the option to turn off WLZ, so the previous diagram may be confusing or my thinking :)

So the 3P option


And I will also ask about the protector in this diagram should it be with N or without?

f-e-r-u wrote:

3P would be the main switch and 4P an option to turn off WLZ so the previous scheme may be confusing or my thinking

Please note that the issues of installation execution are regulated by standards and regulations, and you can start thinking only if you have knowledge of the subject.

Hello
The first diagram is incorrect, you have a TN-C system from the power supply side, there you cannot use a 4p disconnector (named switch in the picture) that will disconnect the PEN conductor (incorrectly described as N in the drawing).
Remember you must not disconnect the PEN conductors in the TN-C network and PE in the TN-S network.
4p switch disconnector (circuit breaker) can be used only after the point of separation of PEN into N and PE. Then the PE conductor must not be disconnected (it serves as electric shock protection), but the N conductor may be disconnected.
Remember that the switch disconnector does not function as a short-circuit and overload protection.
Protection is provided by overcurrent switches.

As for the surge protector from the supply side, you need a 3p type B + C protector (TN-C network system) with a PEN terminal, and not as in the figure 4P with PE and N. ), then you use a 4p arrester with a PE and N terminal.
I refer to the catalog notes of the manufacturer you will use, usually the switching systems of surge arresters are described in detail.

Check the voltage presence indicator in the manufacturer's catalog to see if it requires back-up protection. For example, LK-713 from F&F requires back-up if the upstream protection is> = 25A, then you use e.g. 3xB6 / 1p.

koscik wrote:

Remember you must not disconnect the PEN conductors in the TN-C network and PE in the TN-S network.
4p switch disconnector (circuit breaker) can be used only after the point of separation of PEN into N and PE. Then the PE conductor must not be disconnected (it serves as electric shock protection), but the N conductor may be disconnected.

thanks for the explanation, I wrote the topic that I received a different version of the disconnection as I wrote 4P and 3P but there was no standard and regulations passwords, for me enough info with such a network is supposed to be 3P regulations period.

koscik wrote:

As for the surge protector from the supply side, you need a 3p type B + C protector (TN-C network system) with a PEN terminal, and not as in the figure 4P with PE and N. ), then you use a 4p arrester with a PE and N terminal.

I was looking at Eaton diagrams and in fact the TN-C is 3P spbt12-280 / 3, the question is whether 4P is not on the same protection as if I could buy 4 for the price of 3. Unless you recommend other price-quality protectors?

koscik wrote:

Check the voltage presence indicator in the manufacturer's catalog to see if it requires back-up protection. For example, LK-713 from F&F requires back-up if the upstream protection is> = 25A, then you use e.g. 3xB6 / 1p.

This is what I will have, so I added security.

Hello

In my opinion, Dehn is the leader when it comes to surge arresters. When it comes to Hager surge arresters (these are the previously used blocks), these are Dehn surge arresters in the Hager packaging.
The price of the arrester depends on the number of modules used, so a 3p arrester will be cheaper than a 4p arrester (the same company).
I assume that it is a switchgear in a single-family house.
The selection of the arrester depends on whether the building is powered by an overhead or cable line (what length), and whether it has a lightning protection system. On this basis, it is possible to estimate the expected level of overvoltage to which an appropriate arrester should be selected.
There are many cheaper alternatives available on the market, but in most cases their quality may be questionable, most often it is the most ordinary varistor. In the case of protectors with replaceable members, this is a more expensive solution, however, it allows the replacement of a single member in the event of damage.
Remember that varistor arrester wears out naturally over time, moreover, a varistor arrester, due to its construction, causes minimal energy consumption (mA current), which increases with the wear of the arrester.

Summing up: if the installation of a protector is a requirement of, for example, an insurer, and there are no specific requirements here, you can go to budget solutions (100% price) or install a protector that you will have no doubt will work properly.

Note for mounting the arrester:
The connection of the PEN rail with the PEN terminal of the protector should be made with the shortest possible section of the conductor with the appropriate cross-section;
The arresters have double screw terminals on the supply phase side, so you "put" the power cord (cable) on the arrester and then "drain" from the second clamp.
This shortens the sections of the wires on which the voltage drop occurs, thanks to which the protector will work when an overvoltage occurs.

Hager is just an example from the drawing. I was thinking of Eaton or others, if not qualitatively different.
Yes, a house, an overhead line and then 40m ground to the house. There is to be a lightning rod, now there is a cooperage around the building. I can still see that they protect the ear muffs.

Hello

The arresters are backed up if the previous protection is higher than recommended by the manufacturer (back-up protection).
In the case of a house (16kW) it will probably be gG25A, so you do not need to secure the arrester. The pre-meter protection then protects your protector from the mains supply.

I'm posting as a follow-up as if anyone needed to clear up any doubts


https://www.youtube.com/watch?v=6ecK0AI8UvM