I have a 65x250 metal building to wire, l am going to run the grounding system with 4 electrodes connected to my panel ground bar and then from there to the metal structure, as per Article 250.104 (C), l was told l needed to ground the foundation also, From what l read foundation grounding is not required by code, l think the electrode system and bonding to structure is ok, what do you guys think.
Metal Building
- Thread starter cjamps
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- Location
- Massachusetts
Anytime a foundation will have rebar in it 1/2" diameter or larger and more than 20' in length the NEC requires you to use it.
If you do have a concrete encased electrode to use you can forget adding ground rods.
If you do have a concrete encased electrode to use you can forget adding ground rods.
(I'm unsure if there are any jurisdictions remaining that might still be on a Code prior to the 2005, but if you happen to be under any Code cycle prior to '05 the CEE was not mandatory)
- Location
- Massachusetts
I agree, if you are on the 2002 or previous NEC editions the use of a CEE was voluntary.
A/A Fuel GTX
Senior Member
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- WI & AZ
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- Electrician
Is this a post frame building?
Follow the 1st sentance in 250.50:
250.50 Grounding Electrode System.
All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.
If (A)(1)thru (A)(7) are there, you must use them.
So, if you are under any Code '05 or later and there was 1/2" or larger rebar in the footer, it should have been used as a grounding electrode. If it was there and you did not connect to it then your AHJ probably has a procedure to address that problem.
Carrefully read (A)(3) to see if your building steel qualifies as a "effectively grounded steel frame"
(Note: if it does not qualify as an electrode, you would still need to bond it under
250.104)
Depending on your local AHJ, if you have any of the (A)(1) thru (A)(7) elecrrodes present you may not even need an additional electrode such as ground rods (except metal water must be supplemented).
250.50 Grounding Electrode System.
All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.
If (A)(1)thru (A)(7) are there, you must use them.
So, if you are under any Code '05 or later and there was 1/2" or larger rebar in the footer, it should have been used as a grounding electrode. If it was there and you did not connect to it then your AHJ probably has a procedure to address that problem.
Carrefully read (A)(3) to see if your building steel qualifies as a "effectively grounded steel frame"
(Note: if it does not qualify as an electrode, you would still need to bond it under
250.104)
Depending on your local AHJ, if you have any of the (A)(1) thru (A)(7) elecrrodes present you may not even need an additional electrode such as ground rods (except metal water must be supplemented).
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