On Sunday, February 08, 2015 03:23:44 PM Ralf Mardorf wrote: > On Sun, 08 Feb 2015 21:14:12 +0100, Hermann Meyer wrote: > >Old buildings didn't use grounds, they just have 2 cords and use the > >second as ground and backline. In German this is called Nullung. > >Potential issues are clear with this technique. > > Actually I'm living in an "Altbau" with retrofitted concrete-footing > ground electrode. Potential issues could be caused by tons or grotesque > reasons. Reality has absolutely nothing to do with school books. A ground into concrete is not much of a ground at all. On this side of the small pomd, we are required to drill thru the concrete if its in the way, amd sink 2, 8' copper rods directly into the dirt below the concrete, spaced not less than 8 feet apart. And they are mandated to be connected to both the neutral and the static grounds AT THE ENTRANCE SERVICE AND NO WHERE ELSE. I redid, most of it myself, the service here bsck in 2006, replacing a 60 amp entrace with a 200 amp entrace that the houses 60 amp is now a subcircuit, fixing several problems that I'd be willing to bet were never inspected when this place was built in '70. I had lost several bits of computer hardware, modems in particular due to the EMP from nearby lightning strikes. I have witnessed the transformer pole across the street that my service comes from, being hit several times, with no damage to anything in the house since. The way I have this room wired today, a lightning strike can make the service and everything in here bounce 50 to 100 thousand volts, enough to give me a doorknob shock from a wired keyboard. Zero failures in this room since 2006 when I did that. That didn't even hurt that keyboard but now I use wireless with several inches of air gap. And keep batteries on hand. ;-) Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
