Ufer Grounding and Visqueen????

[Palmbay]

Water piping is all PVC to the road. The main might be copper or brass, but then all the piping they are installing for water these days is PVC. So I don't think the main valve will be sufficent, or worth the trouble to get to the road.

I am just going to drive a rod and tie the Ufer to it and the meter and be done with it. From most replys I dont have much to worry about since the sides of the pour are in contact with earth.

The lightning thing is still something I would like more input on. I have heard some horror stories. I have only seen the normal burnt up devices and equipment. Hell I even had a fire ball shoot through my living room and nail the TV when I lived in NC.

Lightning is a regular occurence in Florida. Usually hear about people getting hit at least 4 or 5 times a year. Just last month a lady got hit taking a walk with her kid.

 

[petersonra]

My guess, and that is all it is, is that any time lightning strikes close enough to your home that some of the energy may travel through any GE to earth is a candidate for serious damage to your house.

Lightning is not 60 Hz. It is a very fast rising transient. Chances of it nicely following a wire to earth you put there for that purpose seems slim. Even minor twists and bends in the wire, or connections that seem quite adequate can look like a near open circuit to a very fast transient.

My take is that lightning is going to go where it wants to.

A typical ground rod is not going to do any good nor is a CEE in the event you get a direct strike.

 

[bphgravity]

During a direct strike, most of the high frequency currents are directed into the earth via the grounding electrode system while most of the 60hz components flow into the electrical system.

For as many lightning strikes there are per year in Florida, there just isn't an overwhelming number of reports of slabs being damaged or destroyed. Here's a picture of one report:

I personally would be more concerned for the combustable materials that lightning currents may fine themselves passing through. Many contractors are quick to route the GEC through an attic and through wood framing members yet don't want to connect to the CEE because the concrete may be damaged? Sounds like fuzzy logic to me...

 

[Shockedby277v]

I think I learned here recently that concentric ko's are now ok to be used for grounding. No grounding bushings required. It caught me by surprise, and I didn't follow up on it. I believe Roger made the post. Someone please correct me if I'm wrong. I'm gonna search for it.

John

Backing up a lil bit. I just wanna make sure I have this straight. A concentric knockout is only good for 20 amps when used as a equipment ground??