Concrete encased electrode

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danickstr

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If a concrete encased electrode is completely encapsulated in concrete, which is an insulator, then how effective of a power dissipater can that system be? It seems like the energy would stay locked in the grid and bounce back at the ground fault, whereas ground rods and water pipes are attached to more conductive earth and would allow the power to drain into the earth.
 
danickstr said:
If a concrete encased electrode is completely encapsulated in concrete, which is an insulator, then how effective of a power dissipater can that system be? It seems like the energy would stay locked in the grid and bounce back at the ground fault, whereas ground rods and water pipes are attached to more conductive earth and would allow the power to drain into the earth.
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I believe that concrete, specially in contact with earth below, has a moisture content that makes it a conductor. Mind you not a perfect conductor like copper, but nonetheless a conductor. Remember that your earth system resistance only needs to be 25 ohms or less. The large area of contact with earth and the water content makes this a low resistance path. e/m.
 
Energy-Miser said:
I stand corrected. However, that means the the resistance of the UFER is typically even lower, right? e/m
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In theory, yes. One of the reasons that a CEE is supposedly superior to a ground rod or two.
 
danickstr said:
would allow the power to drain into the earth.
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That is only if that is where it wants to go.... Electrical current will take ALL AVAILABLE PATHS. Be it water lines, phone line, power lines - rods or ufers. The analogy of "returning to the source" is applicable to generated power only if the generator or transformer is grounded - be it in your building or the many others connected to it - or right at the pole. However the earth is not a return path per-se - IMO the purpose of grounding it to bring expoded conductive object like metering and electrical equipment closer to the electrical potential of the earth or vise versa. And in terms of lightning strikes make every available path and electrode of the system over the widest area availble to disapate the strike.

A CEE/UFER would have the largest surface contact to earth (all of the concrete) as opposed to most made electrodes.
 
It's a common misconception that concrete dries in order to harden. Curing of concrete is a chemical process that can occur even when completely submerged in water.
 
Here's a little info. I have copied ref. concrete.

Concrete absorbs moisture quickly and looses moisture very slowly. The mineral properties of concrete (lime and others) and their inherent pH means concrete has a supply of ions to conduct current. The soil around concrete becomes "doped" by the concrete, as a result, the pH of the soil rises and reduces what would normally be 1000 ohm meter soil conditions (hard to get a good ground). The moisture present, (concrete gives up moisture very slowly), in combination with the "doped" soil, make a good conductor for electrical energy or lightning currents.

Source: Google search on UFer Ground done by another poster on another site.
 
with a standard footprint of a home or office building, concrete grid seems to be a better groundpath than I had realized. thanks.
 
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