Earth Bonding Symbol Question - Page 1
Forum section: electronics / general

author: Leeima
author_rank: Contributor
timestamp: February 20, 2024, 05:26:03 pm
content: Can anyone explain these symbols to me?there's the earth/ground symbol in three variations (that I know) "white on green", "black on yellow", and "white on blue"I know that white on blue labels usually indicate mandatory, but what I couldn't figure out if that meant it was already bonded to earth, or I needed to provide an external earth connection to it.It's a label I have on a rackmount PDU.Ideally I'd use that point as my earth point, and the rest of my earth would be tied to that, but if that is not the case then I would need to get access to the earth from the main cable plugge din

author: mendip_discovery
author_rank: Super Contributor
timestamp: February 20, 2024, 06:02:50 pm
content: https://incompliancemag.com/article/the-grounding-symbols/Colour seems irrelevant but the symbols to differ.

author: AVGresponding
author_rank: Super Contributor
timestamp: February 20, 2024, 06:26:10 pm
content: Generally they are chosen to have good contrast with the background they are to be affixed to. There is no significance beyond that.

author: Leeima
author_rank: Contributor
timestamp: February 20, 2024, 07:07:15 pm
content: Thanks, I thought there may be some obscure wiring regulation denoting the different colour combinations

author: Benta
author_rank: Super Contributor
timestamp: February 20, 2024, 09:21:54 pm
content: Only the green symbol has a standardised meaning.Not because it's green, but because there's a circle around it.This is internationally recognized as "Protective Earth", short: PE.The two other symbols are arbitrary and can mean anything, depending on manufacturer and location.

author: AVGresponding
author_rank: Super Contributor
timestamp: February 21, 2024, 06:14:33 am
content: They all technically have a circle around them. Back to generalisations, but the better the manufacturer, the less ambiguous it is likely to be.

author: EPAIII
author_rank: Super Contributor
timestamp: February 21, 2024, 10:02:23 pm
content: Explain them?Looks to me that the WRONG people are doing things. We have had perfectly good symbols for chassis and if the local electrical codes are followed, EARTH ground for well over a century. There is no reason for such tomfoolery. And the constant invention of new symbols only serves to confuse people and make things LESS SAFE!

author: Leeima
author_rank: Contributor
timestamp: February 23, 2024, 01:04:00 pm
content: The symbol itself is fairly straightforward, what wasn't clear was whether the colours mattered (like it does with electrical wiring)A colleague of mine thought that they might, but I couldn't find any confirmation one way or the other

author: EPAIII
author_rank: Super Contributor
timestamp: March 14, 2024, 07:07:55 am
content: I thought mendip_discovery answered your question in the second post. I was addressing the things others have been saying.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 14, 2024, 07:34:31 am
content: Quote from: Leeima on February 20, 2024, 05:26:03 pmI don't think so, and also never heard of that before. Color doesn't matter.Highly unlikely to be any safety marks based on color alone. The symbol has to have something else distinguishable, other than color alone. The number of color-blind people is quite high, particularly for colors green and blue.

author: mendip_discovery
author_rank: Super Contributor
timestamp: March 14, 2024, 05:41:24 pm
content: Oddly enough the UK does use colours for safety signs.https://www.legislation.gov.uk/uksi/1996/341/schedule/1/madeQuoteThough I doubt it makes a difference with those symbols.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 15, 2024, 06:30:28 am
content: Quote from: mendip_discovery on March 14, 2024, 05:41:24 pmIt doesn't.