hjacobs Posted November 21, 2003 Share Posted November 21, 2003 Here in California you must run a seperate 20' lenght of #4 rebar centered in the foundation to act as a ground. Can someone please tell me why this is better than the rebar that is all connected for the foundation (80' in my case) ?? Thanks Quote Link to comment Share on other sites More sharing options...
SwampNut Posted November 21, 2003 Share Posted November 21, 2003 Strange. Does that rebar connect to "ground" somehow, or just float in the concrete horizontally? It would make sense if it was vertical, or connected to a vertical metal object sunk in the ground deeply. Quote Link to comment Share on other sites More sharing options...
Guest Posted November 22, 2003 Share Posted November 22, 2003 The UFER does connect to the ground . It also is horizontal to the ground. It is actually 60' less in lenght the foundation rebar Quote Link to comment Share on other sites More sharing options...
EVLXX Posted November 23, 2003 Share Posted November 23, 2003 WTF OVER? Quote Link to comment Share on other sites More sharing options...
SwampNut Posted November 24, 2003 Share Posted November 24, 2003 I don't know the answers. I understand electricity very well, and I can envision a few ways that this makes sense, but I don't know exactly how they work out in the real world. One of the simple things I can see is the concept of ground loops or ground differentials. You see two "grounds" can have varying actual potentials. If you put a house ground in the front yard which happens to have rich soil, and another in the back yard which has rocky terrain, they are going to have different voltage potentials. Same with the mess of rebar in a foundation. Having a specific length of an isolated material in there connected to ground would neutralize that. Ground variances can be a big problem because although the voltage differential is small, the potential current is HUGE. With a nearby lightning strike you could actually fry someone standing on a wet bathroom floor with one foot closer to the "low" potential and one closer to the "high" potential. I'm not making this up, it's documented. For example, if a power pole falls near you, you should not walk away from it, you should hop with your feet together to eliminate this problem. Seriously. Quote Link to comment Share on other sites More sharing options...
EVLXX Posted November 24, 2003 Share Posted November 24, 2003 Ya, I work around Heavy equipment alot and It's a general rule that if you cut a power line (underground) that you either stay on the equipment (prefferd) or that you jump clear (not recomended, but accepted). If you stay on the equipment you are insulated from the ground. :grin: If you step off or even possibly jumping off, you can get zapped either by creating the ground or creating a static discharge, because as you jump you are helping to move stored electrons in you and the equipment. I guess what I don't understand is, if this piece of metal is just floating in the slab how does it help grounding, or is it a dispersal thing? Quote Link to comment Share on other sites More sharing options...
SwampNut Posted November 24, 2003 Share Posted November 24, 2003 You said it connects to ground, right? Via a sunken copper rod I assume, or maybe the water pipes? A single centralized conductor in the slab would have the effect of "evening" the ground potential of the whole slab. Oh, also, electrical flow increases oxidation. If the other rebar, which is interlaced and attached, were to flow electricity all the time it would rust and turn to powder. Quote Link to comment Share on other sites More sharing options...
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