On Friday 23 March 2018 19:24:58 a k wrote: > I am in portland . > 30 to 40 v ac I read between water pipe _ which is real ground and > ground on the outlet pin that has cylindrical shape. > Is this normal? > No!
But inspect that pipe, every inch of it all the way to real dirt. There may be a plastic connector, inserted someplace which will break that good ground connection. If so, jumper it from one side to the other with a solidly bolted connection using at least 10 gage solid copper wire. Water, depending on its purity is at best a poor conductor, although it can kill you, and really pure water (distilled or deionized) is an excellent insulator. > On Mar 23, 2018 4:03 PM, "Chris Albertson" <albertson.ch...@gmail.com> > > wrote: > > Aram, > > > > Where to you live? In North America, UK, ....? > > > > Building wiring conventions are different in different places. but > > in general your system, taken as a whole needs to be connected to > > exactly ONE ground reference. No more no less. The best way to > > place a bolt some place and define that is "The Ground" And all static grounds are to be stacked on this single bolt. > > If you have 30+ volts AC on a ground pin on an outlet you have a > > problem that needs to be looked at by a good electrician. It > > should never be that high. Some cases are thinks like corosion and > > loose connections. One cause I that think of is that in some older > > buildings they were allowed to use metal conduit as the ground > > connection. Works OK at first but metal conduit rusts ofter time. > > Now day's we are required to pull a group cable with its own static ground in this cable. > > > > On Fri, Mar 23, 2018 at 2:04 PM, a k <pccncmach...@gmail.com> wrote: > > > hi > > > i reassemble my lcnc mill, and i found that axis move by them > > > self. i think it is something to do with static electricity. > > > i found ground - and when grounded lcnc body of machine - breaker > > > turn > > > > off. > > > > > i measure with dc voltage between machine and ground 2. vdc and > > > when i measure ac voltage between lcnc machine and ground it was > > > 35 v AC. > > > > > > i know that when use real ground like a water pipe and ground in > > > outlet there always will be current they always be 30 v ac. > > > can it cause problem? Yes, and while I'm commenting on a plastic connector, its entirely possible that a teflon taped water pipe joint could be an insulator. > > > thanks > > > aram > > > ------------------------------------------------------------ > > > ------------------ > > > Check out the vibrant tech community on one of the world's most > > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > ------------------------------------------------------------ > > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
