Surge Protector for TN-CS Network: Installation, Recommendations & 3/4-Pole Options

Question

Hello, I have a question about the surge protector, which is planned to be installed in the RG, which parted with modernization. The type of home network is TN-C - connect e NN braid (?) (L1, L2, L3 and PEN) However, behind the meter in RG there is a division on the PE strip into N and PE, and...

michcio · Accepted Answer

From the point of view of limiting surges coming to the devices from the electrical installation side, it is important that the cables connecting the protected installation with the limiter and the limiter with the protective rail of the switchgear in which it is installed are as short as possible. The cables connecting the SPD to the installation are best eliminated by using the V connection, while the limiter should be connected with the shortest possible cable to the switchboard PE busbar. This connection will ensure maximum voltage reduction that will occur in the installation between live conductors (L, N) and PE. The second cable should be connected to the equalizing rail SPD. The length of this cable is particularly important if other installations are connected to the equipotential rail, especially telecommunications and antenna (together with surge arresters for these installations), because it will reduce the value of overvoltage between these installations and the electrical installation (this is especially important for connected devices to more than one installation at a time). The length of the cable connecting the equalizing bar to the ground is of lesser importance here. If the conditions require the use of very long (> 0.5m, in extreme cases> 1m) cables connecting SPD with the expansion rail, it is best to move this rail closer to SPD or SPD move closer to the rail (obviously easier to maneuver the rail than the entire switchboard in which the SPD is ). This is not about insulation (as @jacek Rutkowski has already mentioned), but about proper cable fastening. Longer (according to this manual> 20cm) loose sections of wire are exposed to high electrodynamic forces when passing surge currents (speaking colloquially - they will dance), so they can even be pulled out of the terminals of the devices, so they need to be mechanically fastened. This applies to all conductors, where we expect the surge current to flow, i.e. mainly those connecting the arrester with the installation, with the rails and connecting the equalizing rail with the earth electrode.

emigrant · Accepted Answer

A longer cable> 1 m may be used between the ground terminal in the SPD and the equalizing (or grounding) rail, provided that it is flat (tape). It's about the inductance of the round conductor.

emigrant · Accepted Answer

If the cooper is too short, extend it by tab. Drill holes at 3-4 points, e.g. with a 10-bit drill, and screw tightly preferably with a self-locking nut. The connection should be strong and stable. That's probably the subject.

globus · Answer

4 poles and no discussion (N are treated normally as phased for many years). In addition, they SHOULD be on a separate connection directly to your earth electrode than the rest of the switchboard cy ". This is most preferably looking at the distribution of voltages in the system when the surge arrester works during a discharge. The voltage drop at the earth electrode - arrester connection does not directly affect the potential of the remaining installation.
And as for the costs, evaluate it yourself, even if you spend with 500, what is the cost with any losses in home electronics? However, if you do not have one there, is it worth it at all?
According to me, don't be fooled by the replaceable inserts "Because you can only replace one" and it is "cheaper", and so after a few years it turns out that the producers have stopped producing this model, the other one doesn't fit and you once paid more to have exchangeable and now and yes you have to buy the whole thing again.

emigrant · Answer

Since the supply network is TN-C, the chapter is in RG and there is also to be SPD there, why do he need the N-PE module? After separation, the PE bus is actually a PEN bus with a separate N. Between the PE bus (PEN) and N there is such a small distance within the switchboard that the N-PE module is not needed here. The SPD for the TN-C system should be used. It is different if someone has a PEN division in the connector, or a meter box on the facade, and WLZ to RG is 5-wire and has a few or several meters. Then use SPD for the TN-S system, with the N-PE module, preferably 3 + 1 (with summing spark gap). Then we have galvanic separation of N from PE. There is no possibility of short circuits between N and PE or L and PE. There is no SPD for PLN 500 T1 or T1 + T2. As they are, they should not be on the market because they do not have a cutting off member. For this the author has an overhead connection. The cheapest spark gap T1 + T2 is probably DEHNshield monoblock, the price of which fluctuates around slightly over 1000 zlotys. I think Hager also has something, a DEHNshield clone. It should be cheaper.

paweldre · Answer

Thank you for the reply, but I am surprised by the price. This is even more to ponder, because I do not have such expensive equipment at home and for almost 40 years I have not had experience with surges.
I also read in a few places about the redundant N-PE module in this system.

Hager e.g. here:

https://www.hager.pl/files/download/0/515663_...PL_2014_hager_ochrona_przeciwprzepieciowa.pdf.

emigrant · Answer

Equipment is the least important. SPDs are not used to protect equipment, but to limit overvoltage on SPD terminals and to equalize the potential difference in the electrical installation at the time of lightning. Of course, in a sense, SPD is involved in the protection of electronics. I would have added Hager SPA400 unless you have a lightning protection system. From what I see, you can buy a new one for PLN 800, so the price is quite low. A little cheaper than DEHNshield. You have an outdoor connection, so T1 should not be varistor. I spent over 2000 zlotys on SPD and I don't waste money on the right and left. Mounted and I hope it will never have to work.

paweldre · Answer

Hello,

I still have a question, what effect can the surge protector have on the length of the wire from the grounding terminal in the protector itself to the grounding strip, for example, hoopers? The 16 mm2 cable will be connected individually with a length of about 2 m.

I don't know if it interprets the instructions correctly - SPA400 Hager instruction in combination.
Should the cable through which this connection will be made be additionally insulated e.g. in a tube in case of a high surge current?

Jacek Rutkowski · Answer

In what language, buddy paweldre You are writing? It doesn't have much in common with Polish ... Where did you get this photo from? Some comment is probably there and probably it is about separating the grounding conductors of the protector from others and fixing them in case of discharge. High current during the discharge is able to pull the cable out of the plaster or also stir in the switchboard when it is laid with excess.

lukiiiii · Answer

Is there a household way to build a surge protector? Anyone got such a miracle undressed? What's inside? Varistor and spark gap?

paweldre · Answer

Thank you for reply Is a steel tape at stake, e.g. in the form of a hoopkin not pulled above for switchboards? Regards,

paweldre · Answer

Hello, This SPA400 Hager has no N terminal. Should the PEN conductor be separated, the N conductor be protected? I found an interesting configurator What do you guys say? Regards,

Surge Protector for TN-CS Network: Installation, Recommendations & 3/4-Pole Options

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