How to ground a photovoltaic installation - TN-C installation

Hello. As the topic . How to do grounding. Installation in the TN-C building.
I presented my idea in the pictorial picture.

Thanks for the help.
greetings

electro92 - the structure of the panels is to be protected against lightning, grounding it via GSU is a mistake. This way you run a vertical lightning rod (because this is how you should treat the earthing conductor in this case) inside the building, which is forbidden.
It does not matter if there is a hoop in the ground or a pin earth electrode - there should be 2 clamps:
- for construction outside the building
- to the equipotential rail as you solved it

And by the way, the same is done for TN-cs installations.

Sorry, I did not describe exactly.
My point was that the structure would be connected with an aluminum wire with a diameter of 10mm2 and connected to the hoop (outside) then from the hoop with a 10mm2 cable to the equalizing rail.

Thank you.
greetings

Illustrative drawing:

Almost good
The GSU connection - the earth electrode is made in the underground part.
You need to make 2 control joints, distant from each other> 50 cm, descend from each of them separately with a hoop to the excavation and there you can connect it with a hoop or a pin.

Hello.

To be sure that I understood correctly ??

Thanks.
greetings

electro92 That's ok now.

15kVmaciej wrote:

Hello. Apparently, from time to time, I just need to expose myself to my views in general.
Well, I would be careful with grounding these structures ...

I fully support this point of view, but when they want to "ground" they should do it properly.

15kVmaciej wrote:

Well, I would be careful with grounding these structures. The first argument determining the need for such would be to investigate how many stormy days in a year there are statistically in the region. The second one, what is the geographical situation, I do not have any definition of the landscape, but it is related to the sphere graph - that is, if there are tall buildings or other natural "lightning rods" nearby, I would not invite lightning on my roof. I would actually strengthen the surrounding lightning protection systems so that my roof would remain in their shadow.

You write about lightning grounding, but what about functional grounding?

For example, my CiGSs must not only have a grounded minus, but also have a support structure. Any positive potential on the panel with respect to the environment must be dissipated to avoid PID. For now, I decided that until I come up with a better solution, I will connect it with a 6mm copper cable to the GSU or make a separate earth electrode (I do not have a hoop around the house).

As for inviting discharges, as far as I know, by making a lightning rod, we do not change the "inviting" potential, but we only facilitate the discharge of energy from the lightning. The potential exists even if the roof is an insulator. The use of a lightning protection system allows you to save damage caused by the flow of current through the structure, wires in the wall, etc.

Probably the most sensible thing to do is to make a lightning protection installation that will be above the PV so that the virtual ball does not touch it?

Jan_Werbinski wrote:

For example, my CiGSs must not only have a grounded minus, but also have a support structure. Any positive potential on the panel with respect to the environment must be dissipated to avoid PID.

Functional grounding is another pair of wellies - amorphous panels have their own rules.

Quote:

For now, I decided that until I come up with a better solution, I will connect it with a 6mm copper cable to the GSU or make a separate earth electrode (I do not have a hoop around the house).

In the case of a supporting structure, I would treat it as a lightning conductor - the solution is given above. The 6mm2 cross-section is too small for equipotential bonding. Since you do not have a hoop, what do you have "pinned" GSU on?

What cross-section to use?
GSU with a 16mm2 cable to the driven copper-plated earth electrode, approx. 3 m long.

Jan_Werbinski wrote:

What cross-section to use?

In the event of exposure to mechanical damage, the cross-section should be increased by "mesh" or more, depending on the situation.

Quote:

GSU with a 16mm2 cable to the driven copper-plated earth electrode, approx. 3 m long.

And what is the resistance of this "earth electrode"?
Is this rail really a GSU?

I did not measure, because I usually only have multimeters. The earth electrode will be expanded on the occasion of other works. GSU because that's what I called it and it is a point of separation between PE and N.

Jan_Werbinski wrote:

I did not measure, because I usually only have multimeters. The earth electrode will be expanded on the occasion of other works. GSU because that's what I called it and it is a point of separation between PE and N.

Sorry, but it doesn't work that way - you can't "sculpt" protective installations as you like. I understand that many people speaking in this section are enthusiasts and have quite a creative approach to the topic, but I am observing the entries appearing here with increasing concern.
There is a lot of professional literature where you can find out what solutions should be applied in a specific case.

Literature tells me to carry out a specific renovation, and preferably, with the development of technology, build the house from scratch every few years. Unfortunately, the literature does not specify where I should live at that time and where to get the money.
There are intermediate steps. Partial protection is better than none, and the proof is that the electric shock protection works and the elimination of the negative potential of the panels. Establishing a hoop is the destruction of cobblestones and for the time being I am looking for other solutions.

taniam wrote:

electro92 - the structure of the panels is to be protected against lightning, grounding it via GSU is a mistake. This way you run a vertical lightning rod (because this is how you should treat the earthing conductor in this case) inside the building, which is forbidden.
It does not matter if there is a hoop in the ground or a pin earth electrode - there should be 2 clamps:
- for construction outside the building
- to the equipotential rail as you solved it

And by the way, the same is done for TN-cs installations.

Do I understand that I can connect the panel structures to the lightning protection system, or should I lead a separate hoop to the ground?

https://www.dehn.pl/sites/default/files/uploa...ehn/DEHN-PL/druki/ds109_fotowoltaiczne_pl.pdf

Gentlemen, the topic is worth a further extension!

It is enough to look at a few videos on YT to find out that installations are built where:
a) the panels and the frame have no equipotential bonding at all and are on the roof
b) as above but with ground mounting so they are "so-so" grounded
c) panels connected to the GSU only for equipotential bonding (e.g. 1.5mm2)
d) panel frames and rack connected to the lightning protection system

I am also watching the topic, I am also editing it and I am also confused. There will be a lightning protection device on the ridge (gable roof). The distance to the panel frames is 40-50 cm. Some people write to connect them to the lightning protection ins in this situation, but for my understanding it is probably better to use a thin cable for GSU as in point "c" and 16mm2 to the surge voltage at the DC input to the inverter. How is it for feint, is it a slim chance that the inverter will survive, and how is it going to rock frames? This...? The equipotential bonding and overvoltage protectors will evaporate, the inverter and most of the connected devices will probably burn. But the question remains where the discharge current will go.
Would do otherwise. Connect the lightning protection system to the ring earth from one corner of the building, and the photovoltaic installation on the other side diagonally? Will the lightning protection system be effective in this system if it is connected to the rim at only one point? The electrician obtained less than 3 Ohm from the measurements.

Hello,
Can the inverter and surge voltage on the DC side be connected to the PE conductor in the main switchboard in the TN-S network, can I extend the cable coming from the DC box because it is about 50 cm fi 16mm, there is no lightning protection at home, I made a pin earth electrode to ground the structure and I have 5ohm and I have less on the PE cable, I am asking for a quick answer.

elektro92 wrote:

Hello.

To be sure that I understood correctly ??

Thanks.
greetings

Is it necessary to connect the ground bus of the PV panels to the main GSU in the diagram as presented by electro92? Where a type 1 + 2 3-phase surge arrester will be installed between the GSU and the Inverter. On the Dehn site, it is combined [url=]https://www.dehn.pl/sites/default/files/uploads/dehn/DEHN-PL/druki/ds109_fotowoltaiczne_pl.pdf[/url] . What the electro92 presented seems to me to be a better solution when lightning strikes it goes to the ground and to the surge arresters in front of the inverter from the side of the PV panels, and not to the house installation. I already have confusion in my mind.

Such a situation: the PV installation is located in the garage and has its earth electrode. The cable to the garage is pulled up from the main switchboard from before the security, practically from the partition point and grounding of the PEN.
The question is whether it is necessary / recommended to connect PE with a PV earth electrode in the garage or not?

AC side connected to ground, DC side only remains with PEN without grounding.

Added after 3 [minutes]:

Grabe Jan wrote:

AC side connected to ground, DC side only remains with PEN without grounding.

AC vs DC mistake !!!!

Here you have a nice description of what the PV earthing on the roof should look like if we have a lightning conductor.
http://www.inzynierbudownictwa.pl/technika,ma..._przepieciowa_instalacji_fotowoltaycznej,7874

Each time the installation is earthed.
The case when we do not have a lightning protection system at all is the least favorable, but then the structure should also be earthed, not only because of the lightning / overvoltage protection (limitation of the lightning current in PV DC cables), but maybe also the protection against electric shock, especially if the installation is is within easy reach (skylights).
It is best to do the earthing in the way that the electro92 colleague drew straight, without entering the building with the wire.


One of the largest distributors of inverters in Poland also recommends grounding structures and panels.
http://blog.corab.eu/ochrona-instalacji-fotowoltaycznej-dachu-budynku/

Photovoltaic installation without lightning protection
If, during the appropriate analysis of the risk of lightning damage, according to the PN-EN 62305-2 standard, we receive information that the risk of this type of lightning discharges to a tolerable or lesser degree, we adjust our procedure to the absence of lightning protection. In this situation, the supporting structure of the PV module should be connected to the main rail of the potential equalization in the building with a direct equalizing conductor.

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krzych101 wrote:

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Corrected.

Hello,
I would like to ask you for an answer to my question, and not a pointless posting, it is here and there, because here in the thread there is also a little muddle ...
So I have this situation, I am at the stage of looking for a company that will make photovoltaic installations for me, so what should the grounding issue look like in my case? What's the best? I care about a specific answer and help, not a few dozen that will bring nothing.

Currently, I have a TN-C connection in the building overhead network, the PEN is grounded and separated into N and PE, and the grounding is less than 8 Ohms. In the basement, I have a cordage, where a 16 mm2 cable is connected, and now I have a problem with grounding the photovoltaic installation, what should I do?

The house has no lightning protection, and the structures + modules should be earthed or the protection on the DC and AC + inverter side should be earthed using the existing earthing, an equalizing rail and a hoop in the basement should be built? (The inverter and DC AC boxes will be in the basement due to the more or less constant temperature for the inverter operation) and the cables from the roof will be routed through a ventilation chimney.

Should I make an additional earthing to which I will only connect and disconnect the earthing of the structure + modules and PE conductors from overvoltage limiters? Of course, with the right cross-section. And the hoop from this earthing would also be introduced into the basement.

What is the best way to deal with the grounding issue in this situation? I am asking for constructive help

dakius,
If you cannot read with understanding, you do not have the appropriate knowledge, and at the same time you are a very demanding person, I suggest:
- find a decent designer or preferably an expert in the field of electrical installations and networks,
- commission him to develop a design for the installation with earthing,
- on the basis of the above, look for a company that will do it in accordance with the design.

ghajduk wrote:

If you cannot read with understanding, you do not have the appropriate knowledge, and at the same time you are a very demanding person, I suggest:
- find a decent designer or preferably an expert in the field of electrical installations and networks,
- commission him to develop a design for the installation with earthing,
- on the basis of the above, look for a company that will do it in accordance with the design.

For this there is a forum to ask, and your answer to your colleague's question adds nothing to the discussion.