I've really enjoyed the great discussions on this board the last few days, having just recently found you guys.Lot's of great info and friendly banter. Love that.
Anyway, was just riffling through the latest plans I am bidding the other day, and had to pause for a few seconds..( as my eyes glazed over). On a 400 amp, 480/277v standing Meter w/distribution, the Engineer spec'd out 2-3/4" x 20 FOOT ground rods.Has anyone out there ever seen this??? After sending through my RFI regarding this, it was returned to me , " No correction needed, 20 foot rods " Um....was I always on vacation these past 20 years when these muthas were used?.Or has anyone out there run into this?.
Cheers
NS4M

I just realized i might have posted this to the wrong board section....forgive me, I'm new ;-)
cheers
NS4M

Nope, you've posted just fine. If there is a protocol, I haven't really found it yet. If what you wrote is 3/4" ground rods, 20' long, that is correct, your supplier should be able to supply them with no problem. You may be used to 5/8" - 8' rods, eh? No these will be supplied, most likely, in 10' lengths with a coupling in the middle. They're standard.

NS4M,
You have to remember that the code rules are the minimum requirement. Designers often provide plans and specifications that far exceed the minimums.
Don(resqcapt19)

Thanks for the response George. Yup, I did say 3/4" x 20' . Mostly around here we see alot of 3/4"x 10' rods spec'd, multiple rods, u.g. grounding loops..etc. Just haven't ever seen a 20 footer.. Oh well, ya learn somethin new everyday, sometimes 2 things. Thanks again
NS4M
Ps> Yes Resqcapt19, I agree with the code providing minimums only...and i still remember taking to an enginneer, an old timer. His response to my query of which grounding method to use was " Yup, grounds are good. The more the better".

[This message has been edited by NoShorts4Me (edited 01-15-2002).]

Ok I have the sledge hammer, now climb up to the roof and lets pound this thing in!

About 6 years ago I used an attachment to a jack hammer that clamped onto a rod at any point. You could drive the whole thing from the ground. Havn't seen it since and I cant remember who made it.

A couple of summmers ago I did a few traffic signal installations. 50' rods at the cabinets and 30' at the poles.

Having launched into my tirade last week, when installing grounds at utility poles, it is common to use 3/4" X 10' rods, all with threaded ends. No matter how you drive 'em, you have to protect the end with a case hardened fitting so you can couple on the next one. You will drive rods until 25 ohms is reached and that can be 50- 60'.

Hilti, and Bosch I know made these fittings for their hammer drills, and you'll want to try AB Chance for the pneumatic stuff. If you have more than one to drive, don't try a sledge hammer, if the soil is rock/degraded rock, etc. you will want a air compressor, watch carefully, they will turn around and come back out on you.

Good luck

Ground rod driving at our company has always been a hot topic. After a few small injuries and lots of complaints in our area's rocky " soil" , at least 4 of our trucks were set up with hydralic drivers, plumbed to the pto system ( it also drives our capstans for pulling wire). But man..ya gotta have a back like a gorilla to lift them things.
NS4M

Does the resistance increase on these things with age sometimes?