Control Building Grounding.

You ask the strangest of questions.

This building would be grounded as per any other building, according to the codes and standards in place where the building will be located.

The fact it houses control panels or the fact that it is located close to a substation has nothing whatsoever to do with how the incoming power supply to this building would or should be grounded.

What you may have to pay attention to is how you go about grounding the shields of incoming control cables coming into this building from remote locations.

There is a good page in Wikipedia on grounding/earthing systems. Well worth a read for the general principles.

The answer may also be found by asking the qualified Electrician who makes the connection to the building.

According to BS 7430 19.2 General earthing arrangement of substations-there are six cases considered depending upon transformer position in the substation-or near-and if the low voltage will be supplied for substation auxiliaries only or for other outside consumers.

Only in one case-when the transformer is not a part of high voltage-medium voltage substation then it is required a maximum 1 ohm ground resistance and 430 V earth potential in a high voltage ground fault case in order to be permissible use a common grounding grid for high and low voltage system. If these conditions are not fulfilled then the low voltage neutral and protection conductor shall be insulated and connected to an electrode located far from the high voltage grounding electrode

- 3 m at least.

If the control building is a part of substation and the distribution transformer is located on major part of the substation and if the possible potential rise exceeds 430 V the major substation should not contain a source of supply to an external low voltage network.

According to IEEE [USA] this grounding is treated differently.

IEEE 80 ch. 17.8 Separate grounding:

"The practice of having separate grounds within substation area is rarely used. "There are many disadvantages.

ch.17.9 Transferred potentials:

This transferred potential may be transmitted by communication lines, rails, conduits, low-voltage neutral etc.

17.9.3 Low-voltage neutral wires

This neutral wire shall be treated as "live" and insulated for possible GPR or transferred potential.