Concrete encased rebar for GEC in 2005

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dave81

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So according to the new 2005 NEC are we required to use a concrete encased rebar for our grounding electrode conductor, no exceptions, for any new residences and all structures? Or can we still use cold water and ground rod?....I have yet to get a 2005 book. Thanks for any help here.
 
Re: Concrete encased rebar for GEC in 2005

The rebar is to be used for the supplemental grounding electrode, the water pipe is still the main grounding electrode. In some cases, no rebar is installed in the footers and another acceptable grounding electrode is required. :D
 
Re: Concrete encased rebar for GEC in 2005

In the State of Colorado it will be required to install & use a uffer ground as the main grounding source. I had an Inspector give me a letter that I am to pass on to my contractors stating that they will need to install this when they pour the footings. Of course under Art.250.50 If you have a metal water pipe that has 10' or more of the metal in contact with earth you will also need to use it as part of the grounding electrode system. Under Art.250.104 If the metal water pipe is only in the structure but being supplied by plastic the interior metal water pipe will still need to be bonded accordingly. ;)
 
Re: Concrete encased rebar for GEC in 2005

charlie
The GEC does not have to be installed to the cold water electrode first. One could install the GEC to the concrete encased electrode, and then BOND the cold water to the Concrete encased electrode.
Read 250.64(F).
 
Re: Concrete encased rebar for GEC in 2005

Pierre, the order doesn't matter but the water is still the main and the rebar is still the supplemental electrode. If the water is isolated with an insulated coupling like some water utilities are installing, the rebar would still be there for an electrode. :D
 
Re: Concrete encased rebar for GEC in 2005

Pierre,
The problem with running the GEC to the concrete encased electrode first and then to the water pipe can become a problem on larger services. The code only requires a #4 GEC to the concrete encased electrode, but a full sized, per Table 250.66, to the water pipe. If you go to the concrete encased electrode first, the GEC to that electrode will also have to be full size.
Don
 
Re: Concrete encased rebar for GEC in 2005

2005 - According to 250.52, all the listed electrodes are required if present. I don't see were any one of the seven are described as the "main".

The fact that the water pipe needs an supplemental electrode doesn't imply that it is the main. In fact, it means that it is less reliable. The supplemental requirement is there so that when the municipal changes the metal water pipe to a plastic one(no "if", only a matter of time), with the supplemental electrode already in place, thanks to this requirement, the system is still grounded.
 
Re: Concrete encased rebar for GEC in 2005

That is, of course, why a supplemental electrode is required. I suppose you are correct but when I think of supplementing something, I think of it as being an ancillary. :D
 
Re: Concrete encased rebar for GEC in 2005

In most areas you will not be required to use a Ufer ground if the footers will not have any rebar.

However, it has been determined to be the 3rd best grounding electrode and it normally beats the pants off of a ground rod. If a building is 30 feet by 30 feet ( average house ), the footer is 16 inches wide, and you have rebar or copper wire going all the way around, you have approximately 120 square feet of contact between the higher conductivity concrete and the soil. You would have a hard time beating that!

If your service is over 200 amps you should consider a heavier Ufer ground wire that extends a lot longer than 20 feet in the case of a footer that has no rebars. The first time that I built a 400 amp service I used two 200 amp circuit breakers and use TWO Ufer grounds 24 feet long each in the footer running in opposite directions. This got me out of having to do a crimped tap and I could just simply bond the 2 GECs with a split bolt to get the bonding between service panels.
 
Re: Concrete encased rebar for GEC in 2005

Hi volt101, Check out implication of "main" in [250.53(D)(2)] 'A metal underground water pipe shall be supplemented....'

rbj, Seattle
 
Re: Concrete encased rebar for GEC in 2005

How many have seen a footer without rebar in it :D Oh and yeah roger another post without quoting article numbers ;)
 
Re: Concrete encased rebar for GEC in 2005

Living in New Hampshire, most of us are under PSNH's mercy. I am trying to get an answer of whether we have to drive ground rods still if the ufer ground is being utilized. Although this is not a NEC issue, in the requirements for electric service connections, a handbook that was approved by the public utility commission, it states that the ground rods are to be ran to the meter enclosure(i know this is another controversial issue because of the seal). I can understand there issue as well, if the customer has his service disconnected, started to gut out the building etc. the whole time the utilities meter is floating without a ground. I am trying to get them to accept a proposed standard that we run the ufer ground to the meter and call it good.
 
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