# EGC to footer steel



## MechanicalDVR (Dec 29, 2007)

It depends on the size of the ungrounded conductors, try the table in 250.66 for the proper size.


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## macmikeman (Jan 23, 2007)

denno19 said:


> What size does the ground electrode conductor to a footer steel type electrode have to be. 250.52(A)(3)(2) Refers to using #4 bare copper as the actual electrode but not the size of the conductor if you are bonding to the steel with the required DB type clamp. In our area they have been calling for a #4. In this case I have a separate building with a small sub-panel that requires a supplemental electrode. There is no good place for twin rods and structural steel will be available in the foundation.


Supplemental electrode conductor sizing is covered in 250.53 (E). #6 cu or #4 al if it is a rod, plate , or pipe


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## joebanana (Dec 21, 2010)

So, this isn't a separately derived system, why do you need a supplementary "ECG" for a sub-panel? And why a ufer? If the only available building steel is encased in concrete, why would you want to bond it? Are you running a ground with the feeders?


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## backstay (Feb 3, 2011)

joebanana said:


> So, this isn't a separately derived system, why do you need a supplementary "ECG" for a sub-panel? And why a ufer? If the only available building steel is encased in concrete, why would you want to bond it? Are you running a ground with the feeders?


Separate building, needs rods or a ufer. Plus four wire and no bond between the grounding and grounded condutor.


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## manchestersparky (Mar 25, 2007)

If it is a new structure and there is steel in the footer, you are required to install the Concrete encased electrode. 

The code says the largest you are required to install to a C.E.E. is #4 copper.
(Just like the largest you are required to install to a ground rod is #6 copper.)

Side note : you are talking about a GEC not an EGC.
GEC = Grounding Electrode Conductor ( Table 250.66)
EGC = Equipment Grounding Conductor (Table 250.122)


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## denno19 (May 24, 2017)

Building inspector says a minimum of #4 copper to footer steel. The grounding electrode system for a separate building is required by 250.32 (A) The sub-panel feeders are #4 copper....seems a little much....just sayin"


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## denno19 (May 24, 2017)

Yes...running 4 wires to sub panel. A Ufer would be easier than trying to find a place for rods. Lady is functionally blind and I am trying to avoid trip points. Ground electrode system is required for separate buildings with anything more than a single branch circuit or a single multi-wire circuit 250.32 (A) A multi-wire branch split into 2 circuits with a shared neutral does not get the bye unless you have a generous inspector


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## sbrn33 (Mar 15, 2007)

denno19 said:


> Yes...running 4 wires to sub panel. A Ufer would be easier than trying to find a place for rods. Lady is functionally blind and I am trying to avoid trip points. Ground electrode system is required for separate buildings with anything more than a single branch circuit or a single multi-wire circuit 250.32 (A) A multi-wire branch split into 2 circuits with a shared neutral does not get the bye unless you have a generous inspector


A Ufer is not optional on a new building. The outbuilding has to be treated like a main. It is stupid as **** that we need to run 4 wires but oh well it is what it is.


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## denno19 (May 24, 2017)

You are correct and we are speaking about GEC's the code say's not larger than #4 and the inspector says not smaller than #4...Just trying to follow the twisted road that code language seems to consist of....just sayin'


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## sbrn33 (Mar 15, 2007)

denno19 said:


> You are correct and we are speaking about GEC's the code say's not larger than #4 and the inspector says not smaller than #4...Just trying to follow the twisted road that code language seems to consist of....just sayin'


They already told you 
250.66. 
It can be #8.


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## denno19 (May 24, 2017)

Definitely you are correct....if we were running a 50 amp sub-panel, would they still require a #4 to the Ufer? Or are they saying a Ufer is not an option? This is not a new structure but they are adding enough to the footer to get 20 feet with no plastic under it.


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## sbrn33 (Mar 15, 2007)

denno19 said:


> Definitely you are correct....if we were running a 50 amp sub-panel, would they still require a #4 to the Ufer? Or are they saying a Ufer is not an option? This is not a new structure but they are adding enough to the footer to get 20 feet with no plastic under it.


In my area you better have a ufer then or you will be jackhammering concrete out to get to it. 
and no it only needs to be as big as 250.66 says it needs to be.


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## denno19 (May 24, 2017)

It may be trash but if you were in Manatee County, Florida and tried to install a Ufer for a sub-fed separate building with a small sub-panel...it would have to be #4. I was on the phone with the electrical inspector while reading these posts. Three different guys in three different locales have said the same thing....I'm just trying to find the code language that requires that.


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## sbrn33 (Mar 15, 2007)

denno19 said:


> It may be trash but if you were in Manatee County, Florida and tried to install a Ufer for a sub-fed separate building with a small sub-panel...it would have to be #4. I was on the phone with the electrical inspector while reading these posts. Three different guys in three different locales have said the same thing....I'm just trying to find the code language that requires that.


Dude, that is the largest you will ever have to install, you can always go smaller if your SE conductors allow it. Maybe I am missing something ask them for a code reference.


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## Barjack (Mar 28, 2010)

*250.66 (b)*

I think they are just skimming over this section and not really reading it.

It is definitely a maximum size, not a minimum size, and it is optional, using the language: '...shall not be required...'.



> *250.66 Size of Alternating-Current Grounding Electrode
> Conductor.* The size of the grounding electrode conductor
> at the service, at each building or structure where
> supplied by a feeder(s) or branch circuit(s), or at a separately
> ...


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## sbrn33 (Mar 15, 2007)

I do think if you are installing to a rebar it can be sized by 250.66 if you are burying copper it has to be 20 foot or more of #4.


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## splatz (May 23, 2015)

sbrn33 said:


> I do think if you are installing to a rebar it can be sized by 250.66 if you are burying copper it has to be 20 foot or more of #4.


Sounds right to me, the concrete encased electrode itself has to be 20' of #4, the GEC not necessarily.


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## manchestersparky (Mar 25, 2007)

denno19 said:


> Yes...running 4 wires to sub panel. A Ufer would be easier than trying to find a place for rods. Lady is functionally blind and I am]trying to avoid trip points. Ground electrode system is required for separate buildings with anything more than a single branch circuit or a single multi-wire circuit 250.32 (A) A multi-wire branch split into 2 circuits with a shared neutral does not get the bye unless you have a generous inspector


How would ground rods be a tripping hazard ? If installed per code they would be flush with or below finished grade.


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