Earth Bonding Symbol Question

[Leeima]

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

[mendip_discovery]

https://incompliancemag.com/article/the-grounding-symbols/

Colour seems irrelevant but the symbols to differ.

[AVGresponding]

Generally they are chosen to have good contrast with the background they are to be affixed to. There is no significance beyond that.

[Leeima]

Thanks, I thought there may be some obscure wiring regulation denoting the different colour combinations

[Benta]

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.

[AVGresponding]

They all technically have a circle around them. Back to generalisations, but the better the manufacturer, the less ambiguous it is likely to be.

[EPAIII]

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!

[Leeima]

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

[EPAIII]

I thought mendip_discovery answered your question in the second post. I was addressing the things others have been saying.

[RoGeorge]

I know that white on blue labels usually indicate mandatory

I 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.

[mendip_discovery]

Oddly enough the UK does use colours for safety signs.

https://www.legislation.gov.uk/uksi/1996/341/schedule/1/made

The instructions in the table below apply to all signs incorporating a safety colour.

Colour	Meaning or purpose	Instructions and information
Red	Prohibition sign Danger alarm Fire-fighting equipment	Dangerous behaviour Stop, shutdown, emergency cut out devices, Evacuate Identification and location
Yellow or Amber	Warning sign	Be careful, take precautions Examine
Blue	Mandatory sign	Specific behaviour or action Wear personal protective equipment
Green	Emergency escape, first aid sign No danger	Doors, exits, routes, equipment, facilities Return to normal

Though I doubt it makes a difference with those symbols.

[AVGresponding]

Oddly enough the UK does use colours for safety signs.

https://www.legislation.gov.uk/uksi/1996/341/schedule/1/made

The instructions in the table below apply to all signs incorporating a safety colour.

Colour	Meaning or purpose	Instructions and information
Red	Prohibition sign Danger alarm Fire-fighting equipment	Dangerous behaviour Stop, shutdown, emergency cut out devices, Evacuate Identification and location
Yellow or Amber	Warning sign	Be careful, take precautions Examine
Blue	Mandatory sign	Specific behaviour or action Wear personal protective equipment
Green	Emergency escape, first aid sign No danger	Doors, exits, routes, equipment, facilities Return to normal

Though I doubt it makes a difference with those symbols.

It doesn't.