-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - --On Tuesday, January 14, 2003 12:31:24 +0000 "Stephen J. Wilcox" <steve@telecomplete.co.uk> wrote:
I thought earthing one side of a shielded cable (be it Cat5, or any other type) was actually part of electrical regulations. (maybe I just assumed that as a result of practice)
It varies with local regulations. In .uk, I'd say you need to ground the screen, because a floating screen with potential difference is considered a hazard at work.
It is a known fact that earth varies within buildings, and from place to place in the ground, this is nothing to do with faulty wiring in houses or fault north american continent, this is a simple chemical/physical phenomenon as a result of subtle changes in water tables, salt, minerals etc
So this means there is a difference in potential from point to point - thats voltage to you and me. So if you connect both of these together you get a flow of current - not good..
Current flow is inevitable. The key is to shunt it away ASAP, where "S" means both "soon" and "safe", and to top those requirements, these connections need to look like attractive paths to RF energy, in order to cope with EM/RF interference rules.
Of course, when you ground one end it also means you should be careful when working at the other end not to touch the shied as you are earthed to local ground and it may therefore have a live voltage should you touch it.
See above. Summary: Ground often, ground well, mesh it, do away with long isolated runs, and in general, avoid big potentials. Shunt them. This starts to look like the "peer locally" argument. Good to be back in topic ;-) - -- Måns Nilsson Systems Specialist +46 70 681 7204 KTHNOC MN1334-RIPE We're sysadmins. To us, data is a protocol-overhead. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (OpenBSD) iD8DBQE+JKmW02/pMZDM1cURAnLtAKCaLOfEDcqR1/pYjhBxONvj5UEZTgCeL+PM qa3HlMPD+shfM10Bq9mvHDE= =xD2q -----END PGP SIGNATURE-----