Prints I'm looking at call for driving 20 ft ground rod. I'm not sure of the composition of the ground. Anyone have a good (fast, cheap, easy?) way to run same.

Joan, why not try a UFER?
http://www.scott-inc.com/html/ufer.htm

How about 2 10 foot rods?



Or you could lay the 20 foot rod horizontally in a ditch before backfilling.

Joan,
The ground ring around the Pentagon requires ground rods 1" X 20' every 15 feet, most contractors use an air compressor and jack hammer for the task. BTW, did I tell you guys one of the reasons I've been scarce around here is the move from Dulles to the
Pentagon ? Surprise !!!!!!!

George,
good grief! that would take a while...

Joan,
I just had to install some 10" rods in an area with rock at 3'. I had a soil testing company drill 4" holes 11' deep and installed the rods with sand mix concrete as back fill. The drilling cost about $400 per rod.
Don(resqcapt19)

Sparky,
It takes a bit, but the old building was poorly grounded when built (1941-43) and patched here and there since. This is the first major remodel and lotsa things that were taken for granted years ago will not be overlooked this time. Course, uh.... we also have to fill the hole.

Are 20' ground rods readily available or do you have to Cadweld two 10'?

You can use sectional ground rods to get just about any length. You will need something heavy to drive them-air comressor and jack hammer- depending on the local earth at the job site. Most supply houses will be able to order them for you
Good luck

There's one I had to drive to 140' for a company that produced equipment for MaBell in the '70s. Using 10' sectional rods and a 60# jackhammer, it took all of 2 days in fairly easy dirt.

Thanks to everyone who replied.

George,

Welcome back!

Electure,

By any chance would that company have been Harris? Just curious.

Bill

NJwirenut:
250-83(c)(3) unless we hit rock, have to be "kinda" straight

Hey, speaking of ground rods, you guys have the "cloud to ground" lightning stuff on your weather channel ? We had to move NOAA out of the path of a new runway at Dulles, we had to build them a new detection system of course, and one thing we had to provide was a 400' ground rod, now THAT one may have low impedance. Well driller and GEM in case you had to ask.

Bill,
No, the Co. was Anaconda Electronics (a subsidiary of the big copper Co.)
Although the building changed hands long ago, I'll bet nobody took the time to suck that rod out!!
It was connected to a braided flat conductor equivalent to a 4/0 and grounded a large screen room (Faraday Cage).
(Same Co. had the first computer I ever hooked up, an IBM that took up a 20'x20' room, and didn't have the capabilities of a Palm Pilot)