Wire Size to Ground Rods

[Johnny lester]

Hello. Looking for assistance on ground rod wire sizing.
It seems that, lately, engineers in my area have been using the 250.66 chart to size the wire to the ground rods, instead of the exception of 250.66(A).
Is there a reason for this? Are they misinterpreting the code, or am I? It's right there, in black and white: #6 copper, or #4 aluminum. What am I missing?

 

[roger]

250.66(A) is not an exception, it is a rule. Number 6 is all that is required for the GEC or jumper to a rod.

 

[Johnny lester]

Why are these Engineers speccing a larger ground wire to the rods, then?
Inspector is fine with #6, why not the Engineer?

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[roger]

Why are these Engineers speccing a larger ground wire to the rods, then?
Inspector is fine with #6, why not the Engineer?

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Well, unfortunately all engineers are not educated in the NEC, they shoot from the hip and some think they are experts regardless.
Send them here.

 

[infinity]

It's right there, in black and white: #6 copper, or #4 aluminum. What am I missing?

Yup many engineers like to over engineer and just waste someone's money. Not sure if it comes from feeling warm and fuzzy about specifying their 3/4"X10' triads of ground rods or it's just derived from ignorance.

Regarding aluminum to a rod it would need to be a 10' rod with a little more than 18" above the ground to use an aluminum GEC.

 

[Johnny lester]

Thank you for the information on the aluminum. We try to stick with copper, nice info!

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[Johnny lester]

Infinity, how can we get these specs changed?

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[roger]

Infinity, how can we get these specs changed?

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If they are job specific specs the estimator should have covered it unless they were not paying attention. Specifications can and often exceed code requirements

 

[Johnny lester]

If they are job specific specs the estimator should have covered it unless they were not paying attention. Specifications can and often exceed code requirements

I mean, I have no problems with exceeding code, but this whole issue is just out of hand here, in Ohio. Suppose I could request a redraw.
Engineer claims they have been using this chart since he started, 10 years ago.
I am new to the forum, still learning to quote, etc., and apparently, ground my rods correctly?!?

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[roger]

Drawings can require the magical ground rod triad (some engineers seem to think this is God's gift to grounding) or anything a designer wants to include in their design. My advice to you is that if it was always in the bid documents just make sure it's covered and go with it.

 

[kec]

Many times architects and engineers pick from what is referred to as boiler plate specs to list on there drawings.

I assume they don't what to spend the time typing out what may be accepted in your area.

 

[roger]

Many times architects and engineers pick from what is referred to as boiler plate specs to list on there drawings.

I assume they don't what to spend the time typing out what may be accepted in your area.

Agreed, IOW's they're lazy or not up to speed.

 

[Dennis Alwon]

Hello. Looking for assistance on ground rod wire sizing.
It seems that, lately, engineers in my area have been using the 250.66 chart to size the wire to the ground rods, instead of the exception of 250.66(A).
Is there a reason for this? Are they misinterpreting the code, or am I? It's right there, in black and white: #6 copper, or #4 aluminum. What am I missing?

In most cases you cannot use aluminum to the rod.

250.64(A) Aluminum or Copper-Clad Aluminum Conductors. Bare
aluminum or copper-clad aluminum grounding electrode
conductors shall not be used where in direct contact with
masonry or the earth or where subject to corrosive conditions.
Where used outside, aluminum or copper-clad aluminum
grounding electrode conductors shall not be terminated within
450 mm (18 in.) of the earth.

 

[Little Bill]

Here, one of the POCOs require a minimum #4 to a ground rod. Nothing we can do if we want power.