1. IS THERE A RULE-OF-THUMB OR GUIDELINE ON THE DIAMETER OF A GROUND ROD TO USE FOR A SPECIFIC APPLICATION OR AMPERAGE ? 2. 250.53 G NOW SAYS THAT ALL 2.45m (8 FEET) MUST BE IN INTIMATE CONTACT WITH THE EARTH. HERE IN SO CAL, WE COMMONLY LEAVE A BIT OF IT EXPOSED FOR INSPECTION, CONNECTION, AND MAYBE FUTURE CONNECTIONS. THEREFORE, ARE WE NOW FORCED TO USE A LONGER (3-metre) (10 FEET) GROUND ROD... PER 2002 NEC ? THANKS, GUYS.. JIM GREEN IN LA-LA LAND.
250.53(G) & Ground-Rod size..
- Thread starter ka6chp
- Start date
- Status
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: 250.53(G) & Ground-Rod size..
There is not a rule of thumb but a very clear nec requirement. Its been a 8 foot ground rod as long as I can remember. We use to drive to 7-6 until someone determined it had to be 8 ft and once the DB clamp came out it was then 8 ft. The connection to the ground rod can be buried, thats the way its done locally, including the hundreds I have installed. See 250.68(A)
Keep in mind the 05 NEC will require a concrete encased electrode per 250.52(A)(3), and with it you will not need ground rods.
[ December 11, 2004, 09:47 PM: Message edited by: tom baker ]
There is not a rule of thumb but a very clear nec requirement. Its been a 8 foot ground rod as long as I can remember. We use to drive to 7-6 until someone determined it had to be 8 ft and once the DB clamp came out it was then 8 ft. The connection to the ground rod can be buried, thats the way its done locally, including the hundreds I have installed. See 250.68(A)
Keep in mind the 05 NEC will require a concrete encased electrode per 250.52(A)(3), and with it you will not need ground rods.
[ December 11, 2004, 09:47 PM: Message edited by: tom baker ]
speedypetey
Senior Member
- Location
- Hudson Valley, NY
Re: 250.53(G) & Ground-Rod size..
250.53 also states the end of the electrode should be at or below grade unless protected as per 250.10.
Use an 8' rod and drive it flush.
BTW - Can you turn off your capslock. It is kind of hard to read and in internet terms it is considered yelling. Thanks.
250.53 also states the end of the electrode should be at or below grade unless protected as per 250.10.
Use an 8' rod and drive it flush.
BTW - Can you turn off your capslock. It is kind of hard to read and in internet terms it is considered yelling. Thanks.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: 250.53(G) & Ground-Rod size..
As it stands, it would be up to the AHJ to enforce the concrete guys to provide a Ufer for a Ufer to be present to use when the electricians arrive, right?
IMHO, it's easier to drive a ground rod flush and use #6 as opposed to mounting a service on the living room side of a house, and pull 50' of #4 to a Ufer on the garage wall...
NEC 2005 250.52(A)(3) bears no change bar in the margin, and looks no different. Is there another code that enforces that?
As it stands, it would be up to the AHJ to enforce the concrete guys to provide a Ufer for a Ufer to be present to use when the electricians arrive, right?
IMHO, it's easier to drive a ground rod flush and use #6 as opposed to mounting a service on the living room side of a house, and pull 50' of #4 to a Ufer on the garage wall...
charlie
Senior Member
- Location
- Indianapolis
Re: 250.53(G) & Ground-Rod size..
George, Tom's reference for the new requirement was incorrect. Take a look at the exception in 250.50 in the 2005 NEC.
George, Tom's reference for the new requirement was incorrect. Take a look at the exception in 250.50 in the 2005 NEC.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: 250.53(G) & Ground-Rod size..
Charlie is correct. 250.2(A)(3) has not changed, this is requirement to meet. Whats changed is the new exception to 250.50. The exception states for existing buildings the connection to rebar does not have to be made (darn I miss my electronic version of the NEC), so it means the connection must be made in a new building.
Charlie is correct. 250.2(A)(3) has not changed, this is requirement to meet. Whats changed is the new exception to 250.50. The exception states for existing buildings the connection to rebar does not have to be made (darn I miss my electronic version of the NEC), so it means the connection must be made in a new building.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: 250.53(G) & Ground-Rod size..
That does look harsh, doesn't it?
Can we forsee a widespread move to require this of concrete guys?
That does look harsh, doesn't it?
Ignoring the first half of the statement, "...where the steel reinforcing rods are not accessible for use without disturbing the concrete." CMP appears to be acknowledging how difficult this is to get back once poured...
Can we forsee a widespread move to require this of concrete guys?
charlie
Senior Member
- Location
- Indianapolis
Re: 250.53(G) & Ground-Rod size..
Yes but it will be simple. All that is required is to turn up a piece of the rebar so it will be easy to connect to after the footers are poured. Once they get use to turning the rebar up, it will be automatic most of the time.
Yes but it will be simple. All that is required is to turn up a piece of the rebar so it will be easy to connect to after the footers are poured. Once they get use to turning the rebar up, it will be automatic most of the time.
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