250.52(A)(3) Concrete-Encased Electrode

[raider1]

The reasoning by some that NEC allows an undermined amount of steel tied is bad! This can mean 20 1? steels can be tied in a complete bundle you see the way it?s tied is now debatable

Why is tying steel together to create a 20 foot electrode bad? The whole point of "bonding togeter with the usual steel tie wire" is to create a 20 foot minimum length of rebar.

I will say most of these are posted to figure out how the steel will be installed yet this is not our trade. Worse yet I don?t want a non-electrician installing electrical.

The steel in the footing is not usually installed by an electrician, but instead by a footing contractor. I don't see attaching to reinforcing steel installed in a footing by others any different than attaching to building steel.

Chris

 

[crossman]

Very well put, raider1!

 

[tryinghard]

Why is tying steel together to create a 20 foot electrode bad? The whole point of "bonding togeter with the usual steel tie wire" is to create a 20 foot minimum length of rebar.

Because this is an electrode its purpose is electrical routing.

Install the 20' or more of #4 cu and bond, now THE electrode is the #4 and the steel is simply bonded. Again if the steel does not meet all four elements of 250.52(A)(3) it is not an electrode as defined by NEC.

The steel in the footing is not usually installed by an electrician, but instead by a footing contractor. I don't see attaching to reinforcing steel installed in a footing by others any different than attaching to building steel.Chris

Building steel becomes an electrode after meeting the criteria of 250.52(A)(2) until then it is simply steel framing to bond. Building steel is assembled with rivets and hardware. Footing steel is wire tied, heck for all we know they can use plastice tie wraps!
My greatest point is the electrician needs to install the electrode NOT some other craft!

 

[raider1]

Because this is an electrode its purpose is electrical routing.

This is what the NEC has to say about the funtion of the grounding electrode:

"(1) Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation."

Install the 20' or more of #4 cu and bond, now THE electrode is the #4 and the steel is simply bonded. Again if the steel does not meet all four elements of 250.52(A)(3) it is not an electrode as defined by NEC.

There is no need to install 20' of #4 cu if I have 20' of 1/2" rebar in the footing that is encased in at least 2" of concrete. Again the last sentence of 250.52(A)(3) permits the steel to be bonded together with the usual steel tie wire.

What is the steel bonding if we have 20 feet of copper?

My greatest point is the electrician needs to install the electrode NOT some other craft!

Again I don't see the need for an electrician to install the rebar in the footing, to me this is no different then a steel fabricator installing the steel frame of a building that qualifys as a grounding electrode.

Chris

 

[crossman]

My greatest point is the electrician needs to install the electrode NOT some other craft!

Waterpipe? Building Steel? Metal well casings? Underground tanks? It would be cool if those electrodes were the electiricians responsibility too.

 

[tryinghard]

Waterpipe? Building Steel? Metal well casings? Underground tanks? It would be cool if those electrodes were the electiricians responsibility too.

How would this be cool? These items are not electrodes by the very proof of their spelling, look-em up in the dictionary.

The electrode is not the concrete, metal framer, plummer, well driller?s responsibility; these guys do not furnish or install electrodes heck they can care less about NEC.

The items that are furnished and installed by others may become electrodes but only by the determination of NEC.

Now I?m curious by your definition: who will qualify the CEE as a correct electrode?

 

[tryinghard]

This is what the NEC has to say about the funtion of the grounding electrode:

"(1) Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation."

I am fully aware of what the NEC says is the purpose of the electrode, so much so that I can summarize it by stating, "its purpose is electrical routing", do you see it now? It is the item that connects to earth for lightning and over-voltages, lightning for static and over-voltages to their source.

There is no need to install 20' of #4 cu if I have 20' of 1/2" rebar in the footing

There is if you flip the emphasis to the #4 and properly place the responsibility with the correct trade.

Again the last sentence of 250.52(A)(3) permits the steel to be bonded together with the usual steel tie wire.

This last sentence does not say electrode.

What is the steel bonding if we have 20 feet of copper?

Just more conductive items

Again I don't see the need for an electrician to install the rebar in the footing

I can only answer this with a question: of all the trades who?s responsible for the electrode?

to me this is no different then a steel fabricator installing the steel frame of a building that qualifys as a grounding electrode.

Only if it meets all the criteria of 250.52(A)(2), it's only bonded as per 250.104 until the electrician makes it an electrode. My point with rebar as well.

If the electrician will embrace the responsibility of the electrode the 20? of #4 cu relieves any issues to the rebar, just bond it and own your electrode!

 

[tryinghard]

There is no need to install 20' of #4 cu if I have 20' of 1/2" rebar in the footing that is encased in at least 2" of concrete.

Think of it as a 20' extension of your GEC, only now its absolutely installed correct.

 

[e57]

I can only answer this with a question: of all the trades who?s responsible for the electrode?



Only if it meets all the criteria of 250.52(A)(2), it's only bonded as per 250.104 until the electrician makes it an electrode. My point with rebar as well.

If the electrician will embrace the responsibility of the electrode the 20? of #4 cu relieves any issues to the rebar, just bond it and own your electrode!

[wedding march]
I here-by deem this rusty steel rod about to be encased in concrete an "Electrode" - do I have a witness? Please sign here.....[/wedding march]

Even though I'm beating a dead horse in the other topic of rebar (because it ties into my pet peev of when does the following become a GEC) - I usually use #4cu and make it long enough to get to the panel in one shot..... Charge accordingly...

As for the OP - locally any new or retrofit foundation work or footing 20' in length by code has to get one prior to pour - and needs the Electrical Inspector to sign off on it's install in the pour - many a pour has been stopped as this little botch nails concrete guys left and right - many are from out of town...

250.50. Revise the first paragraph of this section as follows:
250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system. A concrete encased electrode as defined by Section 250.52(A)(3) shall be installed at each new building or structure, and for existing buildings or structures when a new or replacement foundation or footing with a perimeter length of 6.0 m (20 ft) or more is installed. Where none of these electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.
Exception: Concrete-encased electrodes of existing buildings or structures shall not be required to be part of the grounding electrode system where the steel reinforcing bars or rods are not accessible for use without disturbing the concrete.

Bold not mine...

And as some just got done tying rebar and getting the forms set only right before the inspection and have the truck sitting out on the street during the building inspection - Meanwhile the Electrical Inspector is scheduled elsewhere, and wont even show without an "Electrical Permit" - NO POUR - a very costly waste of money. Even if they wanted rebar as the CEE - they need an Electrician to deem it one, and to point it out to an Electrical Inspector. GC's who attempt pull a permit for this usually fail, and the Inspector gets ticked and leaves.... (Rightfully so IMO.)

 

[crossman]

How would this be cool?

More work for us electricians!

These items are not electrodes by the very proof of their spelling, look-em up in the dictionary.

Huh? As far as the NEC is concerned, and when those items meet the code requirments, those items absolutely are electrodes and must be connected together to form a proper grounding electrode system.

The items that are furnished and installed by others may become electrodes but only by the determination of NEC.

Yep. So that means that other crafts DO install electrodes.

[/quote]Now I?m curious by your definition: who will qualify the CEE as a correct electrode?[/quote]

The AHJ should.

 

[tryinghard]

Yep. So that means that other crafts DO install electrodes.

Not as far as they know, ask em

Now I?m curious by your definition: who will qualify the CEE as a correct electrode?

The AHJ should.

I qualify mine and take full responsability when its wrong.

 

[iwire]

Not as far as they know, ask em .

Tryinghard, Crossman is 100% correct, other trades do install other NEC electrodes.

 

[tryinghard]

Tryinghard, Crossman is 100% correct, other trades do install other NEC electrodes.

Bob,

I think you know my real point?

I do have a question for you to answer though: If your GEC connects to the bottom rebar on a rectangle building slab on grade 200? x 50? with a perimeter footing, and 250 lineal feet away the rebar your GEC connects to is 1 ?? from earth are you connected to a NEC electrode?

 

[tryinghard]

Yep. So that means that other crafts DO install electrodes.

Tryinghard, Crossman is 100% correct, other trades do install other NEC electrodes.

LOL

Quote Plummer: Yiep, I?m gona put some lectrodes in today! Got this crack issue on my backside; but anyway.

Quote Well Driller while putting his shoes on in the morning: Wow, can?t wait to get these electrodes in today! I?ve been putin plastic ones in all week, now I get to put in metal!

Quote Framer: Geeze I usually install wooden grounding but now I get to install metal! Those stinken lectricians are always in my way an make me do stuff. Wow I sure agree with them now though, it really is the circuitry that holds the building together! I just glad I?m installing my electrodes today!

Funny ha, ha?HA,HA, HA?

 

[crossman]

Funny ha, ha?HA,HA, HA?

This is getting out of hand.

Situation: A new building is under construction. A plumber installs a metal underground waterpipe with at least ten feet in contact with earth. The NEC considers the waterpipe to be an electrode and it must be connected to the electrical service.

Are you trying hard to tell me that the plumber did not install that waterpipe?

Cuz by gawd, with my own eyes, I saw his apprentice diggin the ditch and I saw the plumber installing the pipe.

 

[tryinghard]

This is getting out of hand.

Situation: A new building is under construction. A plumber installs a metal underground waterpipe with at least ten feet in contact with earth. The NEC considers the waterpipe to be an electrode and it must be connected to the electrical service.

Are you trying hard to tell me that the plumber did not install that waterpipe?

Cuz by gawd, with my own eyes, I saw his apprentice diggin the ditch and I saw the plumber installing the pipe.

No I'm trying hard to tell you the plumber is emphasizing installing water pipe rather than an electrode, and it is not an electrode unless it meets ALL the criteria of 250.52(A)(1) & 250.53(D).

The plumber is not intentionally installing par NEC but if he does than we have to treat it as an electrode, if he does not we cannot use it we have to use a different one as listed in 250.52

 

[crossman]

But the plumber DID install the electrode.:grin:

 

[tryinghard]

But the plumber DID install the electrode.:grin:

Yep if its really an electrode

 

[iwire]

LOL

Quote Plummer: Yiep, I?m gona put some electrodes in today! Got this crack issue on my backside; but anyway.

Quote Well Driller while putting his shoes on in the morning: Wow, can?t wait to get these electrodes in today! I?ve been putin plastic ones in all week, now I get to put in metal!

Quote Framer: Geeze I usually install wooden grounding but now I get to install metal! Those stinken lectricians are always in my way an make me do stuff. Wow I sure agree with them now though, it really is the circuitry that holds the building together! I just glad I?m installing my electrodes today!

Funny ha, ha?HA,HA, HA?

I guess it is to you.:grin:

I am still serious, I don't care if the iron worker assebling a building frame knows he is installing an NEC electrode or not. It happens that he is.

Now later when I install an SDS on the 10 th floor and connect that SDS GEC to building steel I do not go and inspect the each joint of the steel frame.

I assume that the iron workers assembled the steel to long established practices.

I don't see this as any different then assuming the re-bar installers have properly tied the bars. You do realize there are code rules regarding re-bar tyeing, they don't just 'wing it'. :smile:

 

[tryinghard]

I guess it is to you.:grin:

I am still serious, I don't care if the iron worker assebling a building frame knows he is installing an NEC electrode or not. It happens that he is.

Now later when I install an SDS on the 10 th floor and connect that SDS GEC to building steel I do not go and inspect the each joint of the steel frame.

I assume that the iron workers assembled the steel to long established practices.

I don't see this as any different then assuming the re-bar installers have properly tied the bars. You do realize there are code rules regarding re-bar tyeing, they don't just 'wing it'. :smile:

Bob,

I know you know this but the building steel is not an electrode until ALL the criteria of 250.52(A)(2) is met, so the builder is not installing a compliant electrode until these happen.

I do realize the rebar people have standards, I just don't care to track them.