Substation Ground Grid Extension

[an_kore]

Hello all,

We recently finished a wind re-power project which included some modification to the existing collector substation such as, addition of SCADA, new CTPT combo, ground grid extension. At the end of the project, question came up about performing ground grid test/Fall of potential test as the existing fence was moved about 20 feet and ground grid was extended and tied to the existing grid. Is it a requirement to perform FoP test if there is a modification to the grid? I believe it was left out of the scope assuming that the over all existing ground grid must have already been tested and we're only tying into it which would only improve the split factor and make the grid more stringent.

Thanks in advance for any feedback.

 

[mayanees]

There's no NEC requirement, but as the owner I would want it done, as proof that it was installed and to know where the numbers fall.

 

[petersonra]

There's no NEC requirement, but as the owner I would want it done, as proof that it was installed and to know where the numbers fall.

As owner I might want to have it done too, if someone can convince me the cost is worth it.

 

[an_kore]

Thank you for your feedback.

I understand that owner would want it but wanted to confirm that there is no IEEE or NEC code which requires a grounding/FoP test for a ground grid modification.

 

[petersonra]

Thank you for your feedback.

I understand that owner would want it but wanted to confirm that there is no IEEE or NEC code which requires a grounding/FoP test for a ground grid modification.

The word "requires" is interesting.

The NEC is generally adopted directly or indirectly by either states or localities and compliance is thus required by force of law.

IEEE standards are not normally adopted in such a way, so even if the standard says you should do something, it may not actually be required, unless there is some contractual agreement in place that would require following that particular standard.