Electrolytic corrosion from phone ground
I have this horrible feeling I’ve posted this before but forgotten, but I couldn’t find it using the Breaktime search engine.
Last winter, we had to replace the galvanized water supply line on our house where it pops up from the ground in the crawl space after running underground from the street. The plumbing lines run in the air through the crawl space. The phone ground is clamped onto the plumbing lines just above where the line exits the ground. Due to some not entirely solved drainage problems, the ground in the crawl space is damp in winter. The pipe was paper-thin right at ground level and not too bad above and below.
Is it possible that the pipe failed due to electrolytic corrosion from the phone ground? If so, I assume the correct answer is to install an independent ground rod for the phone — ?
Replies
"Is it possible that the pipe failed due to electrolytic corrosion from the phone ground? "
Dunno about that.............but the thing to do would be to tie the phone grounding wire to some grounded part of the electrical service entrance. The grounding electrode conductor would be the most typical place to do it.
Don't use a separate ground rod. You might end up with a problematic difference of potential between your house wiring and the phone wiring.
Ed
I shouldn't need much in the way of wire gauge, eh? 14 gauge should be overkill?
Phee -
14 sounds kinda small. I don't know if it is for physical protection or possible ampacity, but the phone companies tend to ground a residential system with a seemingly large wire, maybe #10 solid.
Ed