Choosing the Right Surge Arrester: 3P Limiter, Type B+C, Spark Gap, DEHNshield DSH TNC 255 & More

Hello. I know that the topic has been discussed many times, but after reading this huge number of posts, I still have doubts about the purchase of the limiter. Installation site switchgear in a TN-C house with a PEN split into PE and N, power supplied by earth from the meter box at the plot border, further to the ground under the road, and then to the overhead network. As I have already read, it should be a 3P limiter (although sentences are divided), protection type B + C (T1 + T2 and sentences are also divided here) which should be based on a spark gap. And now questions arise. Are my assumptions correct? What else should you pay attention to when choosing? And what kind of protectors to buy? I found DEHNshield DSH TNC 255 but what other companies are recommended because there were opinions on forums that manufacturers such as Hager, Legrand make such limiters just to have them on offer.

Regards.

orlicki12 wrote:

Hager, Legrand make such limiters just to have them on offer.

Not completely. The limiter is used with such parameters as needed. It has only been assumed that DEHN is a panacea for everything, but if you need a "spark gap", there is no "big" difference what kind of company, because if it has one, the price is similar.
Hager certainly has one, from dehn, only signed as his own, besides, there is also Phoenix, also generally recommended Obo, but as I said above, you need to know what parameters are needed, and then choose a specific limiter model for them, including that these worse companies / no name cheat on the parameters.

Well, and what parameters should be paid special attention.

If you do not have it in the project, no one honestly counted it, then I would probably choose the "strongest" ones, ie those taking up 8 modules, but the costs are in the range of PLN 2-3,000.

But here also an important role is played by the possible lightning protection system, earth electrode, generally designed installation, distribution of wires, but here we get too far into the topic. It all depends on what you expect from such a protector?

The main thing I care about is to protect the stove in the event of possible overvoltage, I know that this will not guarantee 100% protection, but I think it is worth trying. The lightning protection system is complete. I thought to put on such a protector and additionally some class D near the furnace.

A question of a slightly different nature. I also found a solution from OBO V50-3 + NPE-280. And I am wondering about the connection of this limiter in the TNC-S network. In this case, following the internal scheme:

the varistors protecting subsequent phases are connected in series with one spark gap, and in a 4-wire network the N contact would not be used? I found diagrams in the OBO materials:


The example for a TNC network does not consider the use of a spark gap insert. Hence my theoretical question.

Added after 9 [minutes]:

A similar solution is proposed by Eaton, and the studies do not provide for the use of a summing spark gap in the TNC network, only a solution based on varistors only.

orlicki12 wrote:

My main concern is to protect the furnace in the event of possible overvoltage.
I thought to put on such a protector and additionally some class D near the furnace.

The electronics of the CO furnace are completely different.
It is not damaged by the surges you write about.

I encountered it in practice - you could say it breaks ..... out of nothing.
It is very possible that the manufacturer uses such a definition of overvoltage.

Quote:

Its main significance, however, is the voltage increase above the rated value.
Most often, overvoltage is understood as voltage increase above the maximum voltage value of an electrical installation or device [1].
1. Collective work: Electrical and teletechnical installations - Guidebook of fitter and electrical engineer, Wyd. Verlag Dashöfer, Warsaw 2001, ISBN 978-83-88285-11-0.

It is about voltage rises over 250 V AC.
The protectors T1, T2, and D do not react to this.
For this you need a special protection.

Search the Internet for "protection against voltage increase in 230V network".

Yes, I am aware that for overvoltages below 1kV you need to use voltage relays, but I want to protect the furnace and other expensive devices installed in the house in the future against overvoltage caused by lightning strikes because the network is overhead to the connector, and the house has a lightning conductor installed. Of course, I do not exclude the installation of relays, but as you know, when building a house, you often have to dose the expenses and start somewhere.

orlicki12 wrote:

Yes, I am aware that for overvoltages below 1kV you need to use voltage relays.

For this they will be too free.