When is a loop of ground net copper, not a "ground loop" - Page 1
Forum section: electronics / beginners

author: Faringdon
author_rank: Super Contributor
timestamp: February 21, 2023, 10:52:43 pm
content: Hi, is there any such thing as a loop of conductor that is ground net...but it is NOT referred to as a "ground loop"....and why not?

author: Jwillis
author_rank: Super Contributor
timestamp: February 22, 2023, 01:20:20 pm
content: Quote from: Faringdon on February 21, 2023, 10:52:43 pmNever heard of net ground. Maybe its a reference a Net Potential at ground. For example when a high voltage line is shorted to ground the net potential varies in a radius outward from the live point. This can be several meters . This is why you shuffle or hope across an area of high potential away from the live point to safety when caught in a dangerous situation. That's really the only thing that comes to mind.

author: argile_tile
author_rank: Contributor
timestamp: February 23, 2023, 05:48:10 pm
content: No. There is no such "University Language". You'll either have to ask who wrote it, or run down the facts.in usa homes:neutral: (true is not present in all buildings!)ground: a dead end to over-current-protection-device OCPD (if there are no other failed devices on the branch)earth ground: a single attachment to (the panel) to earth. not the same as ground.ground (by tektronics): all DUT, probes, and scope attached to same "ground" - though with different wire lengths (only acceptable wire length allowed!). there are free lessons on this.warning: TV ground. flyback. there are many grounds - frame is dangerous ground - and no neutral ground. "ground" can be not only biased but also in multiplicity without neutrals.

author: golden_labels
author_rank: Super Contributor
timestamp: February 23, 2023, 06:25:20 pm
content: Quote from: Faringdon on February 21, 2023, 10:52:43 pmThink of ground loop not as a topology, but a phenomenon. It is a situation in which two (or more) points in a circuit, that are intended to have the same potential, do not follow this expectation. And that is because there is an unintentional, often overlooked tiny impedance between those points. While of course loops are formed in such cases (otherwise current could not be present), the problem does not arise from mere existence of a loop.In that perspective, does your question still make sense? Because it seem to be built upon a notion of existence of a loop, while “ground loop” is not caused by loops (they are just a necessary condition, tangential to the entire problem).

author: Infraviolet
author_rank: Super Contributor
timestamp: February 25, 2023, 09:58:56 pm
content: I think some posters here might have misinterpreted the oriinal question. I don't have an anser to it, but might the Op think this wording explains his question better:"Ground loops in circuits can be blamed for noise, ringing, and other unusual and undesired behaviour, because from certain points there can be multiple rather different paths to whatever one tries to think of as a "true" ground for the whole lot. Yet it is really common on PCBs to find ground planes which, on close examination, have loads of loops in them, both around individual small traces of other signals which get forced on t the ground plane layer by spatial cosndierations, and sometiems around large grouped sections of such traces, or whole components. Why aren't gaps in ground planes going to cause ground loop problems?"