hbsandidge
Member
are you now required to ground the rebare in all new construction.
grounding
- Thread starter hbsandidge
- Start date
- Status
rcarroll
Senior Member
- Location
- Fort Collins, Colorado
It's not that you are required to bond the rebar as much as it's you may be required to use the rebar as a grounding electrode. Start with 2005 NEC 250.50 & read from there.
hbsandidge
Member
I have read that section I have a ground loop so do I have to use more than one grounding electrode system or all that are available.
- Location
- Logan, Utah
hbsandidge said:
I agree with rcarrol,
But as a side note if the rebar is in concrete that is in direct contact with the earth the rebar is technically already grounded (ie. connected to the earth).
Chris
Cavie
Senior Member
- Location
- SW Florida
hbsandidge said:
All that are availible.
- Location
- Logan, Utah
hbsandidge said:
Are you using the 2002 or the 2005 NEC. The language in this section has changed from "all electrodes that are avaliable" in the 2002 NEC too "all electrodes that are present" in the 2005 NEC.
This change made the use of a concrete encased electrode mandatory if the rebar is "present" in the footing. It use to be an option as the rebar had to be made avaliable for use.
Chris
Cavie
Senior Member
- Location
- SW Florida
raider1 said:
You are 100% correct. I simply didn't understand what I thought I read. Present is the correct word for 2005 that is why they changed it. I must slow down and let the words sink in. thank you for pointing that out.
- Location
- Logan, Utah
Cavie said:
You are welcome.
It is amazing that just a simple change of wording such as this makes such a huge change in the real world.
Chris
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
raider1 said:
Isn't it mandatory if the rebar is 1/2" or greater? I have never seen anyone use 3/8" rebar but I guess some places do use itt.
rcarroll
Senior Member
- Location
- Fort Collins, Colorado
Yep, it has to be minimum #4 rebar to be considered a grounding electrode.
- Location
- Logan, Utah
Dennis Alwon said:
I should of said it is mandatory if the rebar meets the requirements of 250.52(A)(3).
Chris
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I have seen #3 rebar on a home addition, which is 3/8" of an inch.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
hbsandidge said:
One thing that might not be utterly clear from the posts for far, is that the service - the electrical system - benefits from the connection to the grounding electrodes. They need nothing from the electrical system for the most part, they're not likely to be energized so they don't need to be "bonded" for that purpose.
They are used to minimize the damage to the electrical system due to lightning strikes and other misdemeanors.
The way you worded your question leads many to the idea that you're saying the rebar benefits somehow from the arrangement, which may or may not have been your intention, but that idea is not correct.
An electrode such as a metal water pipe can benefit from being connected to the electrical system (for instance, if accidentally energized). However, the pipe's role as a grounding electrode is a seperate concept from that.
Can you explain what you mean by "ground loop"? Is there something wrong with the grounding system causing problems, or do you mean something else?hbsandidge said:
hbsandidge
Member
I should have said ground ring.
jwelectric
Senior Member
- Location
- North Carolina
This would depend on where the re-bar is located.hbsandidge said:
250.52(A)(3) states that a concrete encased electrode is an electrode that is located in the footing and the footing is in contact with earth.
If you are under the 2005 code cycle then the re-bar would be required to be used as part of the electrode system as outlined in 250.50 (the use of the word ?present?)
Under the 2002 cycle it would be part of the electrode system only if it can be done without damaging the footing (the use of the word ?available?)
North Carolina adopted the wording of the 2002 code cycle so the re-bar is not required to be used in the event of a service change where there is re-bar in the footing.
hbsandidge said:
Here the use of the word ?available? would depend on the code cycle and any amendments that are adopted in your jurisdiction. No matter which cycle all electrodes that are there and can be accessed must be bonded together to form the electrode system.
I assumed that you are talking about the electrode system and also assumed that you were referring to the ground ring.hbsandidge said:
I am also assuming that you have more than one present and you want to know if the ground ring is all that you have to use.
What we must do is bond all the electrodes together to form the electrode system.
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