4 ms·

We're currently building a house in Germany and the grounding consists of a couple dozen meters of thick (maybe 10mm) wiring which is laid out in the concrete g

by myspy 7y ago

We're currently building a house in Germany and the grounding consists of a couple dozen meters of thick (maybe 10mm) wiring which is laid out in the concrete ground plate of the house.

petre 7y ago
A couple of dozen meters? Wiring? Encased in concrete? Five to ten meters of zinc coated 30x5mm flat bar steel bound to three to six 3/4" rods is usually enough depending on the soil characteristics. And it's usuall buried directly in the soil next to or around the bulding. I wonder what bulding codes you've got there.
- brazzy 7y ago
  The relevant code is DIN 18014. And it distinguishes between different kinds of ground plate. Some are considered sufficiently "earth-feeling" to be considered ground themselves, others require separate corrosion-resistant grounding to be put in the earth around them. Zinc-coated steel is not considered sufficiently corrosion-resistant. Here's an article in German with some pictures of how it's done: https://www.elektro-plus.com/elektroplanung/fundamenterder/ausfuehrung-des-fundamenterders https://www.elektro-plus.com/elektroplanung/fundamenterder/a...
  - myspy 7y ago
    Interesting to read. I forgot that below the concrete plate is insulation and they put something in the foundation that touches the earth.
  - petre 7y ago
    Allright. This makes sense as it reduces the electro corrosion on the rebar and also prevents other unfortunate accidents such as the hot wire coming in contact an exposed metal part or a metal pipe which is itself in contact with the rebar. I have seen a scenario where ligtning struck a DHW solar panel installation, skiped from the plumbing to the rebar and also melted hole in the plumbing while doing so, draining all the antifreeze on the walls. In addition it destroyed all the electronic appliances in the house. If the panels along with the rebar would have been properly grounded, such as scenario would have been mitigated.

by myspy 7y ago

We're currently building a house in Germany and the grounding consists of a couple dozen meters of thick (maybe 10mm) wiring which is laid out in the concrete ground plate of the house.

petre 7y ago

A couple of dozen meters? Wiring? Encased in concrete? Five to ten meters of zinc coated 30x5mm flat bar steel bound to three to six 3/4" rods is usually enough depending on the soil characteristics. And it's usuall buried directly in the soil next to or around the bulding. I wonder what bulding codes you've got there.

brazzy 7y ago
The relevant code is DIN 18014. And it distinguishes between different kinds of ground plate. Some are considered sufficiently "earth-feeling" to be considered ground themselves, others require separate corrosion-resistant grounding to be put in the earth around them. Zinc-coated steel is not considered sufficiently corrosion-resistant. Here's an article in German with some pictures of how it's done: https://www.elektro-plus.com/elektroplanung/fundamenterder/ausfuehrung-des-fundamenterders https://www.elektro-plus.com/elektroplanung/fundamenterder/a...
- myspy 7y ago
  Interesting to read. I forgot that below the concrete plate is insulation and they put something in the foundation that touches the earth.
- petre 7y ago
  Allright. This makes sense as it reduces the electro corrosion on the rebar and also prevents other unfortunate accidents such as the hot wire coming in contact an exposed metal part or a metal pipe which is itself in contact with the rebar. I have seen a scenario where ligtning struck a DHW solar panel installation, skiped from the plumbing to the rebar and also melted hole in the plumbing while doing so, draining all the antifreeze on the walls. In addition it destroyed all the electronic appliances in the house. If the panels along with the rebar would have been properly grounded, such as scenario would have been mitigated.