Is the #4 CU connection to the concrete encased electrode required to be made IN the concrete? If a portion of the rebar is left sticking out of the concrete are you allowed to connect there (technically, this portion is not a concrete encased electrode but a buried or exposed rebar)?
concrete encased electrode connection
- Thread starter ga77
- Start date
- Status
charlie
Senior Member
- Location
- Indianapolis
Re: concrete encased electrode connection
It depends on the AHJ and any amendments to the building codes in your area. It is my understanding that all rebar must be encased in concrete. If that rule is not changed, the connection must be made in the footer.
It depends on the AHJ and any amendments to the building codes in your area. It is my understanding that all rebar must be encased in concrete. If that rule is not changed, the connection must be made in the footer.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: concrete encased electrode connection
Some areas allow the connection to be made to the rebar above the footing. Oregon has a detail in its speciality code that specifically shows this.
If the connection is encased, its a $20 clamp, vs a $2.50 acorn clamp for exposed
Some areas allow the connection to be made to the rebar above the footing. Oregon has a detail in its speciality code that specifically shows this.
If the connection is encased, its a $20 clamp, vs a $2.50 acorn clamp for exposed
- Location
- Illinois
- Occupation
- retired electrician
Re: concrete encased electrode connection
Tom,
Don
Tom,
Why? All clamps suitable for direct burial are also suitable for concrete encasement per UL.
Don
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: concrete encased electrode connection
When I was doing work in Florida they use to have a section of re-bar stubbed out right under where the service would go, they would paint it green which I would have to wire brush off. :roll:
When I was doing work in Florida they use to have a section of re-bar stubbed out right under where the service would go, they would paint it green which I would have to wire brush off. :roll:
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: concrete encased electrode connection
I was wrong on the acorn clamp it listed for concrete encasement. The $20 clamp would be a burndy GAR type, which is listed for concrete encasement. but the acorn clamp has to go over an end and the gar can go over the run, however while the acorn clamp can be used, some may not be listed for rebar.
I was wrong on the acorn clamp it listed for concrete encasement. The $20 clamp would be a burndy GAR type, which is listed for concrete encasement. but the acorn clamp has to go over an end and the gar can go over the run, however while the acorn clamp can be used, some may not be listed for rebar.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: concrete encased electrode connection
By supposition, the exception to 250.50 all but states it doesn't have to be encased: "without disturbing the concrete." If there you don't have to disturb the concrete, then you're required to use it.
The only way to use it without disturbing the concrete, is for the connection to be outside.
By supposition, the exception to 250.50 all but states it doesn't have to be encased: "without disturbing the concrete." If there you don't have to disturb the concrete, then you're required to use it.
The only way to use it without disturbing the concrete, is for the connection to be outside.
Re: concrete encased electrode connection
Let's limit the scope of my question to new buildings only.
[ March 24, 2005, 07:35 AM: Message edited by: ga77 ]
Or for the connection to be made before the concrete is poured. I don't have my code book in front of me but I believe the exception regarding disturbing the concrete is for existing installations where it was not intended to have the concrete chipped away to get at the rebar.Originally posted by georgestolz:
By supposition, the exception to 250.50 all but states it doesn't have to be encased: "without disturbing the concrete." If there you don't have to disturb the concrete, then you're required to use it.
The only way to use it without disturbing the concrete, is for the connection to be outside.
Let's limit the scope of my question to new buildings only.
[ March 24, 2005, 07:35 AM: Message edited by: ga77 ]
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: concrete encased electrode connection
Well okay, but: If it's okay for existing installations to connect outside the concrete, and there is no rule prohibiting it in new ones, then it's permitted.
Carry on...
Well okay, but: If it's okay for existing installations to connect outside the concrete, and there is no rule prohibiting it in new ones, then it's permitted.
Carry on...
powermac36
Member
Re: concrete encased electrode connection
Article 250.52, specifies: "the concrete encased electrode conductor shall be 20 ft conductor not smaller than # 4 AWG ," yet;
Article 250.66(A) states: "that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger thatn 4 AWG wire ."
I've heard arguments that 250.66(A) gives the ok to leave a portion of the re-bar out of the conrete, and the bonding jumper can be #8-6CU to, say, a residential service less than 200 ampere rating.
Article 250.52, specifies: "the concrete encased electrode conductor shall be 20 ft conductor not smaller than # 4 AWG ," yet;
Article 250.66(A) states: "that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger thatn 4 AWG wire ."
I've heard arguments that 250.66(A) gives the ok to leave a portion of the re-bar out of the conrete, and the bonding jumper can be #8-6CU to, say, a residential service less than 200 ampere rating.
buck33k
Senior Member
- Location
- Washington state and North Carolina
Re: concrete encased electrode connection
If the connection to the rebar is not encased, it must be accessible. 250.68(A) I have seen this accomplished using a plastic mud ring and plate where the rebar is stubbed up.
Buck
If the connection to the rebar is not encased, it must be accessible. 250.68(A) I have seen this accomplished using a plastic mud ring and plate where the rebar is stubbed up.
Buck
pierre
Senior Member
- Location
- Westchester County, New York
Re: concrete encased electrode connection
I have heard the same requirements as Charlie. My advice is to contact the building inspector to find out the rebar requirement in your jurisdiction, than you know where you need to start from.
I am consulting(not inspecting) on a project now, where the building has been blasted into bedrock (imagine the inspector asking for groundrods
I have heard the same requirements as Charlie. My advice is to contact the building inspector to find out the rebar requirement in your jurisdiction, than you know where you need to start from.
I am consulting(not inspecting) on a project now, where the building has been blasted into bedrock (imagine the inspector asking for groundrods
charlie
Senior Member
- Location
- Indianapolis
Re: concrete encased electrode connection
Pierre, that will make a great installation. Well past the Code requirements and it will serve the owner well.
Pierre, that will make a great installation. Well past the Code requirements and it will serve the owner well.
Re: concrete encased electrode connection
One of the reasons for a minimum amount of concrete cover for rebar is to protect the rebar from moisture so that it will not be weakened by corrosion. Rebar should not be stubbed out underground or where exposed to weather. We have allowed the rebar to be stubbed up inside the building or inside a framed stud space. As Buck mentioned, in these cases the connection must be kept accessible.
One of the reasons for a minimum amount of concrete cover for rebar is to protect the rebar from moisture so that it will not be weakened by corrosion. Rebar should not be stubbed out underground or where exposed to weather. We have allowed the rebar to be stubbed up inside the building or inside a framed stud space. As Buck mentioned, in these cases the connection must be kept accessible.
Re: concrete encased electrode connection
My book says "An electrode--encased by at least 2in of concrete,LOcated within and near the bottom of a concrete foundation or footing that is in direct contact with the earth"--- It does not say " or bent up into an above grade area" . I guess it's an option in some areas.
Arizona has been using UFERS for quite awhile now,most EC opt for tying 20ft. #4 to grid with no connection needed underground.
frank
My book says "An electrode--encased by at least 2in of concrete,LOcated within and near the bottom of a concrete foundation or footing that is in direct contact with the earth"--- It does not say " or bent up into an above grade area" . I guess it's an option in some areas.
Arizona has been using UFERS for quite awhile now,most EC opt for tying 20ft. #4 to grid with no connection needed underground.
frank
Re: concrete encased electrode connection
Frank,
But 250.52(A)(1)says 20 ft of one or more bars and that these bars my be bonded together by the usual steel tie wires. The bar that is bent up will have it's horizontal leg tied to other bars in the footing so that the 20 ft of bar at the bottom of the footing will be accomplished.
After adoption of the 2005 NEC, the #4 copper in the footing not connected to the reinforcement will not satisfy the code. The rebar is there and will need to be used as an electrode. Connecting the #4 copper to the rebar with a proper clamp will satisfy this requirement.
Frank,
But 250.52(A)(1)says 20 ft of one or more bars and that these bars my be bonded together by the usual steel tie wires. The bar that is bent up will have it's horizontal leg tied to other bars in the footing so that the 20 ft of bar at the bottom of the footing will be accomplished.
After adoption of the 2005 NEC, the #4 copper in the footing not connected to the reinforcement will not satisfy the code. The rebar is there and will need to be used as an electrode. Connecting the #4 copper to the rebar with a proper clamp will satisfy this requirement.
Re: concrete encased electrode connection
I gave your reply some thought. I think that what is allowed for existing installations may not be allowed for new. In other words, a less than perfect connection on existing installations is better than no connection at all. But for new installations the best connection is in the concrete where the connection is not subject to any kind of deterioration. I don't buy the argument that an exception for existing installations applies to the general rule. An exception is just that and is narrowly defined by the language in the exception.Originally posted by georgestolz:
Well okay, but: If it's okay for existing installations to connect outside the concrete, and there is no rule prohibiting it in new ones, then it's permitted.
Carry on...
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: concrete encased electrode connection
There's no code requiring/forbidding it aboveground/embedded, so you end up where you started: calling the inspector.
[ March 29, 2005, 10:31 PM: Message edited by: georgestolz ]
I'll buy that reasoning.
True, but when you step away from what the code forbids or requires, to what you think the code intends, devining meaning from exceptions and portents sometimes yields results.
There's no code requiring/forbidding it aboveground/embedded, so you end up where you started: calling the inspector.
I have been going rounds with this trying to make sense of it. One section is defining an electrode, and the other is specifying the size wire to pull to it, how does "250.66(B) gives the ok to leave a portion of the re-bar out of the concrete" pop out?
[ March 29, 2005, 10:31 PM: Message edited by: georgestolz ]
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: concrete encased electrode connection
What about this scenario, if the footer is not poured yet but contains 3/8" rebar then is a concrete encased electrode still required? I just started a service upgrade at a dwelling with an addition that will have new footers with 3/8" rebar that was specified by the architect. Since the footer is only formed could it be argued that I would still need to install 20' of bare #4 AWG copper in the footer or is nothing needed since the rebar is less than 1/2" as specified in 250.52(3)?
What about this scenario, if the footer is not poured yet but contains 3/8" rebar then is a concrete encased electrode still required? I just started a service upgrade at a dwelling with an addition that will have new footers with 3/8" rebar that was specified by the architect. Since the footer is only formed could it be argued that I would still need to install 20' of bare #4 AWG copper in the footer or is nothing needed since the rebar is less than 1/2" as specified in 250.52(3)?
- Location
- Illinois
- Occupation
- retired electrician
Re: concrete encased electrode connection
A concrete encased electrode is only required to be used if it is "present". There is no concrete encased electrode in your installation and the code does not require you to install one.
Don
A concrete encased electrode is only required to be used if it is "present". There is no concrete encased electrode in your installation and the code does not require you to install one.
Don
- Status