service ground

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ronaldrc said:
Rob

We don't know if its two panels or one yet no one mentioned a wiring scheme.
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Yes, that's true. I was commenting on sizing the GEC for a 400 amp service or running one GEC for a 200 amp panel and tapping off of it to the other 200 amp panel.
 
infinity said:
The minimum size GEC for a 400 amp service would likely be #1/0 from table 250.66.
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I believe it can be and usually is #2 copper in the case of two service panel.

It would depend on which note is being used. If there are no service entrance conductors than I agree 1/0
 
Dennis Alwon said:
I believe it can be and usually is #2 copper in the case of two service panel.
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The GEC is based on the conductors supplying the panel, if you run two separate GECs from each panel to the electrodes it could be sized on the 200 amp conductors.

But don't most people run one GEC from the service to the electrodes and in that case the single GEC must be based on the 400 amp conductors.
 
iwire said:
But don't most people run one GEC from the service to the electrodes and in that case the single GEC must be based on the 400 amp conductors.
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Correct- one GEC with two panels than Note 1 comes into effect and a #2 is required. Note 2 changes the scenario
 
3/0 copper--- 167800 cir mil. Times 2 equal 335600. This is equivalent to 350 KCM. Table 250.66 states #2 copper.
 
buckofdurham said:
fisb
The #2 wire. Don't forget to strip it or paint it green, something.
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Actually that is not necessary although I do tape the ends. Taping is not even necessary for a GEC-- at least I haven't seen a code reference for it.
Edit- mistype
 
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If the Ho2 water line is on the opposite side of the house and you have not did anything yet I would use a #2 green copper conductor our electric supplier carries the larger sizes in green now as a stock item.We used to have to put green tape on it, but most know its a ground anyway. :)
 
I know Bob

The last one I did they ask me if I wanted green it is a regular stock item.I
assumed it might be a couple cents higher per ft. but I didn't ask,this was before copper went sky high. :)
 
Dennis Alwon said:
3/0 copper--- 167800 cir mil. Times 2 equal 335600. This is equivalent to 350 LCM. Table 250.66 states #2 copper.
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That's true and the reason I used the word likely in my response. If using parallel conductors of #3/0 you can use a #2, if using a single set of conductors than using 310.15(B)(6) or 310.16 would require a minimum of 400 Kcmil which takes you up to #1/0 for a sinlge GEC.
 
iwire said:
Ronald there is no code reason to use green insulation, tape, paint or make the GEC bare.
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True.

Since the price of coppper has gone up, I've just about used all of the short pieces (drops) of #6 and #4 stranded Cu (of various colors) that I possess.
Been using it for the GEC and water bond on 200A residential services.

No complaints from the inspector.

steve
 
I love the code articles with the pictures from mike holt.

I love the code articles with the pictures from mike holt.

They should have a whole code book like that!! P.S where do you get those pics from?
 
Maybe I breezed over this but it is common for the POCO to pull the service conductors to the main panel if it is underground fed. If you were using a 400 amp residential panel (320amp continuous) with 2 200amp breakers in it, would you base your water main ground conductor on there wire size? or the combined size of your conductors from the meter ( package unit ) to the pair of 200amp breakers. It is common for the POCO to pull in much smaller conductors then you would expect, and basing the ground conductor to the water main on this fact would directly affect the size of the wire. #4 cu may be just fine based on this as long as POCO is 250kcm AL or smaller.
 
acrwc10 said:
Maybe I breezed over this but it is common for the POCO to pull the service conductors to the main panel if it is underground fed. If you were using a 400 amp residential panel (320amp continuous) with 2 200amp breakers in it, would you base your water main ground conductor on there wire size? or the combined size of your conductors from the meter ( package unit ) to the pair of 200amp breakers. It is common for the POCO to pull in much smaller conductors then you would expect, and basing the ground conductor to the water main on this fact would directly affect the size of the wire. #4 cu may be just fine based on this as long as POCO is 250kcm AL or smaller.
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No-- if you had two 200 amp panels then you would find the cir mil of the 2 sets of se conductors, not the poco wire.

So if you have 3/0 you would look it up in the Table , then double it and see what size it is equivalent to. I did this in a post in this thread.

3/0 copper--- 167800 cir mil. Times 2 equal 335600. This is equivalent to 350 KCM. Table 250.66 states #2 copper.
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I was thinking 4 or bigger.
But as you are saying, I can run black #8 to my h20 ground ??
How long have I been doing extra work stripping my 1/0 etc...??

Even had an inspector make an other contractor I know change his # 4 h20 grd. to green or strip it.
 
buckofdurham said:
I was thinking 4 or bigger.
But as you are saying, I can run black #8 to my h20 ground ??
How long have I been doing extra work stripping my 1/0 etc...??

Even had an inspector make an other contractor I know change his # 4 h20 grd. to green or strip it.
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Of course you can use black, I buy bare copper myself...
 
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