My building savings contract pointed out to me during our new build that the potential equalization for the grounding of the satellite system must not be installed together with the other electrical wiring. The green-yellow conductor now runs through our bathroom bundled together in a large cable harness all the way down.
The standards
recommend that antennas only be grounded in protected rooms, especially in lightning protection zone LPZ 0B, no longer directly, but be protected according to the state of the art with separate lightning rods.
Direct grounding with min. 16 mm² Cu, 25 mm² aluminum, or 50 mm² lightning conductor wire is still permitted according to the recognized rules of technology (= the minimum standard). In the fortunately rare case of direct strikes, partial lightning currents are inevitably coupled into the antenna system and the connected end devices.
The risk of overvoltages entering via the supply lines is significantly higher, which is why surge protection according to DIN VDE 0100-443:2016-10 and DIN VDE 0100-534:2016-10 is, in my opinion, even more important than external down conductors.
Does the conductor for grounding the satellite system have to be installed separately?
I pointed this out to the electrician, who did nothing. And now time is a bit pressing because the plumbers are preparing the floor for the underfloor heating and the cables will soon be covered.
Unfortunately, it is common installation practice that grounding conductors, mostly 16 mm² Cu, are installed inside by installers as lightning conductors due to a lack of awareness of lightning protection issues regarding dangerous proximities and are moreover connected using largely unsuitable connectors without certification according to the test standard Class H = 100 kA (links are prohibited in this forum).
The example illustrations in IEC 60728-11, which is relevant for antenna safety, show that sufficiently insulating equivalent separation distances at discharges from lightning protection systems and separate lightning rods are mandatory. A grounding conductor of mostly 16 mm² Cu connected directly to the antenna mast is by no means safer and actually heats up more than 50 mm² lightning conductor wire; nevertheless, no example illustration shows a separation distance with the abbreviation
"s" for direct grounding.
In 2012, I applied in the responsible standards committee DKE/K 735 to adapt the example illustrations for direct groundings to physics and to also depict separation distances there. Since electricians are not trusted to calculate equivalent separation distances, it was at least decided that external down conductors would become mandatory. However, this decision was not incorporated into IEC 60728-11:2016.
Even before the latest IEC 60728-11 has come into effect in Germany as DIN EN 60728-11 (VDE 0855-1):2017-10, a revision was announced, during which hopefully separation distances for grounding conductors of antennas will also be clearly specified.
CONCLUSION:
[*]Lightning current-carrying grounding conductors of rooftop antennas should be installed without dangerous proximities to persons and other conductors, which usually requires external down conductors.
[*]Accessible grounding conductors must be installed in PVC conduits with 3 mm wall thickness according to IEC 60728-11.
[*]A chain is only as strong as its weakest link; band grounding clamps and HES that are not certified according to test standard Class H offer only questionable protection and are not compliant with standards.