I know that the service will need 2 parallel 500cmil runs and the grounding conductor should be a 1/0 copper. I was told by 2 different inspectors 2 different answers. First one says that 2 - 1/2" ground rods cadwelded is enough. The second says 3 - 1/2" rods. Which is right?
How many ground rods for a 800amp service?
- Thread starter thalford
- Start date
- Status
- Location
- Massachusetts
Both of them are asking for more than the NEC requires.
mcclary's electrical
Senior Member
- Location
- VA
I agree, one rod at <25 ohms and you're good to go.
- Location
- Massachusetts
And forget the cad welding and 1/0 as well.
thalford, an 800 amp service in the middle of nowhere could be grounded with just 6 AWG to a single ground rod or in some case two rods.
But I doubt your service is in the middle of nowhere, give us some details, is there a metal water service, is there a structural steel frame, is there 20' or more of 1/2" re-bar going in the footing?
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Why is that?
mcclary's electrical
Senior Member
- Location
- VA
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
What is the load calculation? If it's more than 760-amps, this may not be large enough.
Steviechia2
Senior Member
- Location
- Massachusetts
Code requires only a # 6 going to your G rod
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
- Location
- Connecticut
- Occupation
- Engineer
I'd say NONE are required, if a metal underground water pipe electrode and metal from electrode are available.
- Status