Ground Grid Depth

[Cris Lima]

Good day to everyone. I would like to ask any information if a bedrock is encountered during trench excavation for the grounding loop, is the 30 inches minimum depth can be reduced? Thanks!

 

[Dennis Alwon]

I assume you mean a ground ring. I do not see any exceptions for it

(F) Ground Ring. The ground ring shall be installed not less
than 750 mm (30 in.) below the surface of the earth.

 

[Cris Lima]

Thanks Mr. Dennis for this info. Just a follow up question, if the project specs states less than the standard depth per NEC say 450 - 600 mm, may I humbly ask which shall govern between the two?

 

[don_resqcapt19]

Thanks Mr. Dennis for this info. Just a follow up question, if the project specs states less than the standard depth per NEC say 450 - 600 mm, may I humbly ask which shall govern between the two?

If it does not meet the depth required in the NEC, it cannot be used as a grounding electrode.

 

[Cris Lima]

If it does not meet the depth required in the NEC, it cannot be used as a grounding electrode.

Thanks a lot Sir!

 

[winnie]

Keep in mind that there is no burial depth requirement for a grounding electrode conductor or bonding jumper or random _non energized_ bare wire.

So if the project specification has something that it calls a ground ring made of bare wire buried 6" deep, that is perfectly permitted, and the spec requires its installation.

It simply does not count as a required grounding electrode.

-Jon

 

[Cris Lima]

Keep in mind that there is no burial depth requirement for a grounding electrode conductor or bonding jumper or random _non energized_ bare wire.

So if the project specification has something that it calls a ground ring made of bare wire buried 6" deep, that is perfectly permitted, and the spec requires its installation.

It simply does not count as a required grounding electrode.

-Jon

Thanks for the clarification Sir Jon!

 

[petersonra]

Sort of like the ground ring around a pool is not a grounding electrode but is a buried wire.

 

[GoldDigger]

Sort of like the ground ring around a pool is not a grounding electrode but is a buried wire.

Which rather than pulling connected metallic elements toward remote earth instead modifies the local earth potential to match the connected metal.

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