Ground Rod under equipment pad

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Carlos B

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Can the ground rod location be underneath the equipment foundation? The ground rod is driven to depth with an exothermic 2/0 connection. is it allowable to have GEC conductor transitioning to above grade inside or under the equipment?
thank you!
 
As long as you have the required full 8' of the driven rod(s) in the ground, the connection can be made in those areas.

You will need a 10' rod to meet the 8' burial requirement if are connecting above grade and the connection point will need to accessible.
 
Sounds like this is an auxiliary electrode, if so in the eyes of the NEC you're free to do just about anything that you want.
 
infinity said:
Sounds like this is an auxiliary electrode, if so in the eyes of the NEC you're free to do just about anything that you want.
Click to expand...

250.54 actually says this.

250.54 Auxiliary Grounding Electrodes. One or more
grounding electrodes shall be permitted to be connected to
the equipment grounding conductors specified in 250.118
and shall not be required to comply with the electrode
bonding requirements of 250.50 or 250.53(C) or the resistance
requirements of 250.53(A)(2) Exception, but the
earth shall not be used as an effective ground-fault current
path as specified in 250.4(A)(5) and 250.4(B)(4).
Click to expand...

My take is that it can't be an auxiliary grounding electrode unless it is a grounding electrode as specified in 250.52. The only requirements you get a pass on are the bonding and resistance requirements as noted.

So, for instance, I don't see how a 6 foot rod would qualify as an auxiliary grounding electrode.

Having said that, I don't recall any provision of the code that bans bonding of a piece of metal that is stuck in the ground that is not either a grounding electrode or an auxiliary grounding electrode.

ETA: I think all this provision does is allow you to install what would otherwise be a grounding electrode and not have to bond it to the other grounding electrodes by calling it an auxiliary electrode.
 
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petersonra said:
250.54 actually says this.



My take is that it can't be an auxiliary grounding electrode unless it is a grounding electrode as specified in 250.52. The only requirements you get a pass on are the bonding and resistance requirements as noted.

So, for instance, I don't see how a 6 foot rod would qualify as an auxiliary grounding electrode.

Having said that, I don't recall any provision of the code that bans bonding of a piece of metal that is stuck in the ground that is not either a grounding electrode or an auxiliary grounding electrode.

ETA: I think all this provision does is allow you to install what would otherwise be a grounding electrode and not have to bond it to the other grounding electrodes by calling it an auxiliary electrode.
Click to expand...

I agree, an auxiliary electrode has some requirements, a piece of rebar stuck in the earth with a length of wire could be connected if you were so inclined.
 
it has occurred to me that this provision for auxilary grounding electrodes pretty much says you don't have to use all of the grounding electrodes that are available as long as you designate them as auxiliary grounding electrodes. That's kind of a bizarre result of the provision but it would appear to be accurate.
 
petersonra said:
it has occurred to me that this provision for auxilary grounding electrodes pretty much says you don't have to use all of the grounding electrodes that are available as long as you designate them as auxiliary grounding electrodes. That's kind of a bizarre result of the provision but it would appear to be accurate.
Click to expand...

It makes sense in that the system is already code compliant and for whatever reason you want to add something that will likely do nothing.
 
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