On Friday 23 March 2018 17:04:51 a k 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, probably by blowing "pins" on the interface card. Most of this stuff is 5 volt, or 3.3 volt. 30 volts will blow it.
You either do not have a useable static ground on your machine or its wired wrong, machine or building to be determined. I've had to correct a goodly number of so-called static grounds made up by a carpenter that knew nothing about the NEC code book and treated them as interchangeable. Static grounds are to be bridged to powerline neutral ONLY at the building service entrance according to our NEC. If you are not capable, get an electrician who is. There is no shame in doing so. Basically, with that single connection opened in the service, and the building entrance breaker opened, there should be no continuity between the static ground and anything that is the wide pin of a wall socket, or to an earthen ground. The building, if you have continuity to the narrow pin of a wall socket, make sure everything is turned off first, but the person who wired it, maybe 40+ years ago, is color blind. And you stand a good chance of being shocked, or worse... Connected back up, but the breaker still off, you should get not more than an ohm, maybe 2 ohms, between the static ground and the neutral (wide pin) of a wall socket, any and all places in the building. Good luck. > 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 -- 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
