Ground rod placement

[flyfisher7]

The new garage is almost complete (waiting on concrete slab). I was wondering where to place the ground rod. Does it have to be outside? I was thinking since I don't have concrete yet, I can install it inside under the panel and they can concrete around it. Will this be OK.

Also, if I have to place it outside, how far below grade does the head (top) need to be? Can the ground wire be underground from building to ground rod?

Thanks!

Steve

 

[Aceman]

If this is a new building with a concrete footing and rebar installed that should of been your grounding electrode. An inspector could make you chip concrete to attach to that rebar if he wanted too.

But to answer your question, rods must be driven in flush or below the surface spaced a min. of 6' apart. You can run bare copper ground wire through dirt.

Your inspector will need to see the rods before they're covered. We always leave the tops exposed showing the acorn/ground wire connection.

 

[bdog]

If you have no inspections to worry about I would drive them under the panel as you described. Actually I wish I would have done that myself.

 

[rodm1]

attach it to a solid 20ft piece of re-bar then pore your concrete slab over it.

http://books.google.com/books?id=Zl...snum=1&ved=0CBMQ6AEwADgK#v=onepage&q=&f=false

http://www.nachi.org/forum/f19/re-bar-ground-rod-22990/

 

[oleguy]

if the let you put it inside,you just have to have access to acorn.don't know about where you are,but for outside ground wire i use metal flex covered solid copper.cones in a roll just like bx.

 

[Norcal]

Unless you can prove 25 ohms or less of resistance* a 2nd ground rod is required per NEC 250.56 (2005 ed.) ,the 2nd rod must be at least 6' apart from the 1st one.

*Unless you have have the testing equipment (the instrument is about $3K)to prove you meet the 25 ohm req. it's cheaper to drive a 2nd rod & call it good.

 

[rodnok1]

Just drive two rods in outside like was mentioned, but different areas may have requirement to ground any rebar.

 

[1963 type 1]

Just a tip, Watch out for drain tile . Dont ask.....

 

[sberry]

New code calls for grounding to rebar in new construction. With rods I prefer to get them under or near a drip edge, somewhere there is ground moisture. Ideal to have them driven right into the water table.

 

[larry_g]

Call your local inspector and he will tell you what HE wants to see. Around here you can lay the ground rod under the concrete if it is longer than 20', and the inspector checks it before you pour. Ground systems change and what your localcality may require could be different than anywhere in the country. It is good to put your location in your profile so that questions like this can be better answered. I'm sure that Aceman in eastern Oregon faces different requirements in his high desert country that I do here in the Valley.

lg
no neat sig line