Earthing Of Control Panel At 400kv Substation?

Follow your local power distribution codes.

Only authorized people should be allowed in a 400kV substation. To gain authorized access most power distribution providers require that a person documents what they will do, first. This proves the one trying to enter knows what has to be done. Very often additional safety protocol training must be up to date. You do not know what is relevant or should be done.

GET OUT!

I guess an ac arc is just mild for this magnitude of supply Fred, it's only 400kV. Hmmm. I think this guy should not be even qualified to take the pre -employment screening. Big project right there, management must be cost cutting the heck out of it.

You mean like this little switch.

230 kV might be a little safer.

Exactly.

If you are working in the area of the control panel, you should already know the answer.

If you are a manager, ask a qualified engineer.

If you are an accountant, read the bill of materials supplied by the project engineer or project manager.

Otherwise, stay far, far away and let the qualified people do their jobs.

Or, try it both ways, and report back, if still alive.

Since the grounding methods at this level of voltage environment are not widely known, and in fact change from time to time, I am going to afford you the assumption that you are knowledgeable but desire to get a variety of opinions & practices as a comparison to what you now understand or a design engineer has directed to be done.

In the western US, all is connected to the earth-mat system. I will leave other regional responses to folks elsewhere around the globe.

Pls. seek the guidelines on British Standards or NEC about this, just to be sure.

Earth at purpose is different.Better to connect it to LV earth bus and earth pits can be interconnected.Earthmat is not connected to the body earthing or fence earthing normally

I don't think you intend to work in a 400 kV substation without a suitable authorization.In my opinion from the few words in the open post none could conclude what is your knowledge in the field. Still you have to give more specific details [for instance]:

-Is the control panel mounted in a control building? Then the building is provided with a separate grounding system-finally connected with the substation grounding grid.

-Is the control panel mounted outdoor close to the high voltage apparatus?

First of all the grounding grid has to be calculated, executed and periodically tested for touch and step potential.

But, since a short-circuit current in the control panel supplied from a low-voltage transformer-usually mounted in the control building-has to return to the source a low-voltage grounding conductor [or path] has to be provided. This short-circuit current does not increase the touch and step[ general] potential since it does not flow through the earth.

And I am sorry Noudge79: NEC and British Standard [BS7671] are for low voltage-or medium voltage-only. May be NESC ch. 9 it could help here.

You have to consult IEEE 80/2000.