ufer grounding

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dhsvcs

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miami
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electrician
For ufer requirements, what is minimum amount of attachment points with no 4 cu to rebar if rebar is over 20 ft long and unbroken ?
 
In miami-dade county, I heard some inspectors were asking for 3 attachment point to insure a good ground..
 
dhsvcs said:
In miami-dade county, I heard some inspectors were asking for 3 attachment point to insure a good ground..
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Unless your local AHJ actually requires 3 connections. As far as I know you only need one for NEC.

Unless they can enforce it, they would be getting only one connection unless they wanna fork out the extra crimps.
 
One connection is all that's required and the rebar is not required to be unbroken. 20-12" pieces tied together is code compliant for the CEE. Sounds like someone is making up their own rule.
 
Buck Parrish said:
Perhaps they're concerned the concrete will crumble. :(
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Perhaps explode, it is possible with lightning. I know because I have seen it twice in my career. In the last twenty years, POCO's are moving their communication networks off public networks for security purposes. Pretty hard to hack a closed system. The two methods they use are fiber optics and microwave radio. Fiber is run inside the Static Neutral line. When the static line is brought inside the equipment shelter, utilities used a CEE for the ground, then bonded to sub-station ground. The discharge current enters the facility CEE system during a close-by lightning strike or utility fault. Concrete is a sponged full of water that turns to steam when thousands of amps flow. The result is a steam explosion that destroys the foundation.

Upon further investigation, it dawned on me the sequence of connections was the root cause. The electricians followed the NESC but overlooked a detail. The bonding jumper from the Static line went to the CEE first passed through the foundation rebar bonded to the sub-station ground grid. The fault current was forced through the foundation to reach dirt because it was wired in series,

The solution was simple. Bond the Static line to the substation ground grid first, then a parallel bond to the equipment shelter CEE.
 
We had a simple solution, we installed 20' #4 in the footer and connected it to the rebar. If one failed we still had the other.
 
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