?how to sink a ground electrode this time of year

Are there any tricks to driving a ground rod into the frozen ground on the north side of a building in Minnesota?

Also, normal 8 foot 5/8" diameter steel-core copper rods are customarily used here, but shouldn't they really extend about 8' below the frost line rather than just below the ground surface? If so, would a 3/4" galvanized pipe make a better electrode, since it is two feet longer and would more than double the electrode surface in unfrozen ground, plus give another 2 feet of good electrode when the ground freezes?

Best regards, Bob

Reply to
zxcvbob
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According to zxcvbob :

A proper pile driver (chunk of heavy pipe with a cap on it with handles), or a sledge hammer in a pinch.

I don't know if there's a trick other than "patience, man" ;-)

It doesn't have to go 8' below the frost line. It doesn't really have to be below frost line at all. It just has to get well into undisturbed dirt. Preferably vertical, but it doesn't have to be - as deep as you can get it.

3/4" galvanized pipe is not code. "Ground rod" is ground rod for a reason.
Reply to
Chris Lewis

I have a T-post driver that's pretty heavy. I'll try that. Also an assortment of sledgehammers, up to 20#. But I don't want to bend the electrode trying to get it started.

I wonder if shining a 250W heat lamp on the ground overnight would help much, or would be a waste of electricity...

Actually, I think galvanized pipe *is* code in the US, unless they changed it recently. The inspector only wants one electrode, and I've purchased an 8' rod already and I'll use it. I just wonder if adding a second 10' iron electrode later when the ground thaws would be better (especially in the winter) than a second 8' copper-clad electrode.

Best regards, Bob

Reply to
zxcvbob

If you have any larger pipe hanging about, you might want to sleeve it - will prevent it getting bent, and be a little easier on the hands.

Prolly not.

It is? I thought zinc coatings do nasty things if they have current flow into soil chemistries. They tend to chalk up, which will impair conductance.

So, while a galvanized pipe (ie: water line) might be considered a grounding electrode, you may not be able to use a ground-rod-sized chunk of galvanized pipe as an electrode (only). In other words, if you have to drive one, they prefer "real ground rod".

I don't think frost-line is relevant. If it were, then almost _nobody_ here would have a grounding electrode...

[Hint: frost line can get as low as 8 feet.]

NEC states:

1) you pound in an electrode. 2) Test it for dirt resistance 3) if it's > 25 ohms, pound in another electrode. 4) you're done [Ie, Note: if you don't get below 25 ohms with the second electrode, you don't need to pound in a third.]

In Canada, requirements are more regional, decided by local inspectors who know the local dirt characteristics. [Subject to CEC _minimums_ of course.]

Reply to
Chris Lewis

When I was driving right of way rails. Real 8'-10' pieces of rail road track, we rigged up a 2.5" exhaust extension from the tail pipe with an funnel on it. Set it on the ground and in a few minutes the snow was gone and out we went to drive another rail. I was never sure it actually did anything other than melt the snow. Usually after the first foot we were away from the frost any way. Couple of gallons of near boiling water would seem easier

Reply to
SQLit

Pour some hot water on the ground. Work the ground rod up and down until you meet a lot of resistence. Remove rod from hole and add more hot water. Then work the rod up and down again. Repeat, adding water/working rod up and down until 3 or 4 feet of the rod is in the ground, then drive it home with a sledge hammer. Depending upon the soil, the rod may be able to be "driven" completely with just water. Best to use a sledge hammer after the first 3 or 4 feet is in, though.

Reply to
volts500

Hi, To check how good the ground is, try to light a bulb between it and 120V hot wire. If it lights up bright, you know it is good. Tony

Reply to
Tony Hwang

Even better is if it will blow a 5A fuse, or measure >4 amps with an ammeter.

I probably will test it with a 100W lightbulb, though. I doubt that I can get under 25 ohms in the frozen ground, and the inspector only wants one rod anyway.

Best regards, Bob

Reply to
zxcvbob

I've got frost down to 52 inches below the surface. Driving anything is impossible. Trying to melt it with hot water would be a hoot. Some things are best left 'till summer.

RB

SQLit wrote:

Reply to
RB

According to zxcvbob :

FYI: Mike Holt's NEC guide refer to the 5A fuse trick. This appears to be the common electrician technique.

Reply to
Chris Lewis

I spent a half an hour pounding a ground rod into the ice today with a 20 pound (yes 20!) sledge hammer. There's still a 4" stub above the ground. I haven't hooked up the wire yet because I need to excavate a bit so the clamp is under ground. When I'm all done, I'm gonna disconnect the neutral wire at the panel. Then screw a 5A edison fuse into one of the lamp sockets and throw the switch and see what happens. It seems a lot safer than handling the hot and ground wires out there on the wet concrete.

I don't think the inspector cares whether I have less than 25 ohms to ground, but I'm curious about it.

-Bob

Reply to
zxcvbob

Oh yah. Holt's book indicates the usual technique is a 5A automotive glass fuse in a pigtail holder, and does give a loud "be careful doing this!".

But it's probably safer than any of the other effective testing alternatives.

Let us know what you find.

Reply to
Chris Lewis

I don't have this book, but if it says to use a 12VDC fuse to test a dead short accross 110V, I don't know that I would call this safe.

Reply to
Zaf

According to Zaf :

There's nothing inherently 12VDC about an automotive glass fuse. They're exactly the same thing as used in electronics at 120VAC. They, and their holders are just easier to find in the automotive department. Cheaper than Radio Shack.

Reply to
Chris Lewis

The difference is that some fuses will stand off 12 volts but not 120 or

240 volts when open.

RB

Chris Lewis wrote:

Reply to
RB

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