Why ? Because we humans historically tend to connect with our feet to the soil, and if any touchable conductor has the same potential
as the soil, there is no hazard. This works only in reasonably wet areas.Grounding Safety is about the voltage_difference_ we can reach as humans using hand and legs to bridge distances.
In the northern countries, and in the mountains the soil is mainly rock, and does not conduct electricity well enough
to function as a safety "ground" (actually "safety rock"). The utility their relies on other mechanisms for safety then soil ground.
The soil is connected to the surface of our globe. If we could reach the moon with our hand, there would probably
a huge discharge current between the two bodies, because the moon is not grounded.
Ground is relative. Inside a metallic volume, ground has no meaning anymore, because you need to touch
the metal wall before you can touch ground. Inside such a volume the 'ground" is the metal wall.
All conductive items need to be connected to the volume (=ship) wall to remain safe.
It makes no sense seeking for our globes soil potential (ground) inside a metallic volume.
Gert Gremmen On 8-7-2019 20:19, [email protected] wrote:
Hello group,Is there a real ground in a ship? i.e if a Class I product is used on the board of a ship, does the ground pin actually doing anything? The ship is floating in the ocean and I cannot understand if there is a real ground there or not? Can you guys educate me please?Thank you Peter - ----------------------------------------------------------------This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected] <mailto:[email protected]>>All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.htmlAttachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc.Website: http://www.ieee-pses.org/Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected] <mailto:[email protected]>> Mike Cantwell <[email protected] <mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected] <mailto:[email protected]>> David Heald <[email protected] <mailto:[email protected]>>
-- Independent Expert on CE marking Harmonised Standards (HAS-) Consultant @ European Commission for RED and EMC EMC Consultant Electrical Safety Consultant - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
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