Just checking

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joeyww12000

joeyww12000

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Chatsworth GA
From the utility transformer pad we pulled 4 runs of 4 size 500 Aluminum, A B C N in 4 seperate PVC conduits. In the switchgear copper GEC's to ground rod, building steel, rebar in footer and copper water pipe. The GEC's to ground rod and rebar in footers are 1/0 which is correct for size 500 service entrance conductors. The GEC's to building steel and water piping was smaller guage maybe a #1 I could not tell clearly, I just know it wasnt 1/0. Shouldnt all GEC's on supply side be the same size? Also would the fact that the service conductors were run in parallel change the GEC size?
 
Looks to me like this is all wrong. First of all, you have 4?500 Al. As per T250.66, GEC should have been a 250 Al or 3/0 Cu.
 
After further review, the GEC to the rod could have been a #6 cu as per 250.66(A) and a #4 to the CCE as per 250.66(B).

That said IMO you have a problem to the water as per 250.104(A).
 
Joey I agree with Chris and while not really important to your question I wonder what service size this is?
 
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so you must add all service conductors together in each conduit to get correct GEC size? So 4x500=2000, thats over 1750 which requires 3/0 copper or 250 aluminum. Im sure the foreman on this job didnt do any figuring on this, he went by print specs.
 
joeyww12000 said:
so you must add all service conductors together in each conduit to get correct GEC size? So 4x500=2000, thats over 1750 which requires 3/0 copper or 250 aluminum.
Click to expand...

That is correct.
 
chris kennedy said:
After further review, the GEC to the rod could have been a #6 cu as per 250.66(A) and a #4 to the CCE as per 250.66(B).

That said IMO you have a problem to the water as per 250.104(A).
Click to expand...
So if the GEC has to only be #6 copper or #4 aluminum connected to rod or pipe what is table 250.66 for in relation to 250.66 (a). As for concrete encased grounding electrodes GEC's only have to be #4 copper. I dont understand why table 250.66 shows GEC's much larger???
 
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