Concrete-Encased Electrodes
- Thread starter pgordon
- Start date
- Status
- Location
- Massachusetts
Nothing about the size of the foundation or footing, if it has 20' of 1/2" or more rebar in it you must use it.
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
I'm not speaking for Bob but all grounding electrodes present must be used therefore if the new addition has the 20' of 1/2" rebar in it, it must be connected to the existing grounding electrode system via #4 copper.
- Location
- Massachusetts
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
What must be done if you have a metal building that has individual footings for each column (all with re-bar, I think they are 6' square x 6' deep)?
With footings of that size, I would guess that they will each have at least 20' of rebar and would each qualify as a concrete encased electrode. However, per the last sentence of 250.52(A)(3), you would only be required to use one of them.
One caveat, if by chance the existing structure has a concrete encased electrode and that electrode has been included in the existing grounding electrode system, then adding the new electrode into the system would not be required.
You don't need to bond the rebar. Typically the rebar is used as a ground.
If your electrical system is grounded (ground rods/CCE/water main), you are good.
If your system isn't grounded, you may want to use the new rebar (20' x 1/2") as a ufer ground.
Ok , a 1970 new england home (ranch) with an existing service and an existing electrode system. we are contracted to provide wiring for a small addition with 20' of 1/2 '' rebar or more in its foundation, and a 200 amp service up grade. must i ground or bond the rebar of the new foundation ?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I believe the code would require you to bond it back to the service , however, many jurisdictions do not require you to do it. I would check with the inspector and see what they require.
- Status