rods on rock

[tommyrice]

if i drove a ground rod vertically and hit solid rock,then pulled it back out and drove it at 45 degree angle and hit rock so that 1 foot still is above grade,could i bent top 1 foot over and cover it with dirt or would i have to lay rods horizontally 30" below grade?

 

[cpal]

what is the lenght driven??

 

[Dennis Alwon]

if i drove a ground rod vertically and hit solid rock,then pulled it back out and drove it at 45 degree angle and hit rock so that 1 foot still is above grade,could i bent top 1 foot over and cover it with dirt or would i have to lay rods horizontally 30" below grade?

8' is required to be below grade but I won't tell you that I have never cut a ground rod before in that situation. :grin:

 

[mcclary's electrical]

if i drove a ground rod vertically and hit solid rock,then pulled it back out and drove it at 45 degree angle and hit rock so that 1 foot still is above grade,could i bent top 1 foot over and cover it with dirt or would i have to lay rods horizontally 30" below grade?

I've beenin this situation, and the code proper way to do it is dig down 24", and bend it over horizontally. If you do this right at, or barely below grade, you will most likely not pass. I've tried it

 

[infinity]

The requirement is that you install the rod vertically 8' deep at an angle not greater than 45?. If this is not possible due to rock then you can bury the entire rod horizontally. I see no wording that would permit you to bend over and bury just the top portion of the rod.

250.53(G) Rod and Pipe Electrodes. The electrode shall be installed such that at least 2.44 m (8 ft) of length is in contact with the soil. It shall be driven to a depth of not less than 2.44 m (8 ft) except that, where rock bottom is encountered, the electrode shall be driven at an oblique angle not to exceed 45 degrees from the vertical or, where rock bottom is encountered at an angle up to 45 degrees, the electrode shall be permitted to be buried in a trench that is at least 750 mm (30 in.) deep. The upper end of the electrode shall be flush with or below ground level unless the aboveground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10

 

[chris kennedy]

I won't tell you that I have never cut a ground rod before in that situation. :grin:

Your cutting off the manufactures stamp, easy bust for the EI.

 

[infinity]

Your cutting off the manufactures stamp, easy bust for the EI.

Do all rods have those? Since 5/8" rods aren't required to be listed do they have stamps?

 

[mcclary's electrical]

The requirement is that you install the rod vertically 8' deep at an angle not greater than 45?. If this is not possible due to rock then you can bury the entire rod horizontally. I see no wording that would permit you to bend over and bury just the top portion of the rod.

I was taught the way I posted above, after rereading, that's probably not correct. I see what you mean about the enire rod part, I never realized it said that.

 

[chris kennedy]

Do all rods have those? Since 5/8" rods aren't required to be listed do they have stamps?

I couldn't tell you. I use 5/8 and 3/4 copper clad here as per specs and both are stamped. Anyone got a 5/8 galvie on the truck they could take a quick look at?

 

[realolman]

The requirement is that you install the rod vertically 8' deep at an angle not greater than 45?. If this is not possible due to rock then you can bury the entire rod horizontally. I see no wording that would permit you to bend over and bury just the top portion of the rod.

I agree with the lack of specific wording, but I think it would be silly to not allow it. The whole rod would conform to one of the ways that are permissible.

 

[buffnitup]

What about plate electrode?

 

[infinity]

What about plate electrode?

A big piece of metal buried in the ground. Here are the requirements:

250.52(A)(7) Plate Electrodes. Each plate electrode shall expose not less than 0.186 m2 (2 ft2) of surface to exterior soil. Electrodes of iron or steel plates shall be at least 6.4 mm (? in.) in thickness. Electrodes of nonferrous metal shall be at least 1.5 mm (0.06 in.) in thickness.

 

[buffnitup]

Yup. Sounds like the next best option. Thanks infinity.

 

[jxofaltrds]

if i drove a ground rod vertically and hit solid rock,then pulled it back out and drove it at 45 degree angle and hit rock so that 1 foot still is above grade,could i bent top 1 foot over and cover it with dirt or would i have to lay rods horizontally 30" below grade?

No do not bend the top.Yes you can bury it (them).
Look at exhibit 250.24 in the handbook.

 

[RICK NAPIER]

Ask the AHJ they may let you bend the ro 30" down.

 

[jxofaltrds]

Ask the AHJ they may let you bend the ro 30" down.

I see no harm in doing that but the handbook does not show it that way.

Would I turn it down. No.

 

[RICK NAPIER]

That is why I said ask the AHJ since it would be a judgement call and not a clear code issue.

 

[wxstevens]

I couldn't tell you. I use 5/8 and 3/4 copper clad here as per specs and both are stamped. Anyone got a 5/8 galvie on the truck they could take a quick look at?

I am looking at a 5/8 with no marks.