<html><head></head><body>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.<br>
Potential issues are clear with this technique.<br>
-- <br>
<br><br><div class="gmail_quote"><br>
<br>
Ralf Mardorf <ralf.mardorf@alice-dsl.net> schrieb:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre style="white-space: pre-wrap; word-wrap:break-word; font-family: sans-serif">On Sun, 8 Feb 2015 09:06:40 -0800 (PST), Len Ovens wrote:<br />>It appears we have power coming from two power entrances with two<br />>different earth grounds to the panels.<br /><br />I experienced potential difference for the ground in old buildings<br />between two main sockets, less than 3 meters difference between those<br />sockets, both fed by the same power, coming from the same fuse and<br />connected to the same concrete-footing ground electrode.<br /><br />Even if the power should come from two different sources, one building<br />should have one concrete-footing ground electrode for ground, so in<br />theory there shouldn't be a potential difference.<br /><br />Buildings sometimes don't care about school books.<br /><hr /><br />Linux-audio-user mailing list<br />Linux-audio-user@lists.linuxaudio.org<br /><a href="http://lists.linuxaudio.org/listinfo/linux-audio-user">http://lists.linuxaudio.org/listinfo/linux-audio-user</a><br /></pre></blockquote></div></body></html>