Regarding electricity, which sentence is correct?

1)The machine and the electric board must be earthed independently.

2)The machine and the electric board must be grounded independently.

What I mean is that both (the machine and the electric board) must have an independent wire (the wire that avoids the user receiving electricity).

Thank you for your help.
In the US, we'd say "grounded." I suspect the verb "to earth" may be a British usage, although I've often heard it in scientific literature.

We also use "earth" as an adjective, as in "an earth ground." It sometimes has special meaning, eg, a steel rod of specific diameter driven a specific distance into the ground (as opposed to, say, a water pipe).
(to which your "wire" connects)

(the wire that avoids the user receiving electricity).I'm shocked! Emotion: surprise

Also in the US, we say "electric panel," rather than "board."

Are you refering to the panel on the machine itself, or one, for example, on the wall, to which the machine connects? (The latter seems more likely.)

On the machine itself, we'd distinguish between the "electrical panel" containing relays, transformers, etc., and the control panel(s), on which pilot lights, push buttons, selector switches etc. are mounted.
Of course the term "circuit board" is used in the US, as the sort of thing found in computers. This is a board made of insulating material on which electrical pathways of solder are tracked to components which are soldered in.

"Electrical panels" are made of steel, to which the components are bolted. And the components are wired to each other by means of flexible insulated conductors (wires).
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Avangi (the wire that avoids the user receiving electricity).I'm shocked!Emotion: surprise

Well I just wanted to make myself clear but maybe it was worst!!!Emotion: embarrassed
I suppose the correct expression is " you don't get shocked", if the machine is correctly grounded you won't get shcocked. Is that correct?

It works for me. As long as you don't open up an electrical enclosure without first killing the power, and stick your fingers where you shouldn't. Emotion: big smile
I'll take your advice. You never Know, I might end working as an electricianEmotion: big smile

Thank you again for your kind and so useful help.
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Good luck! Stay grounded! [H]