Permited Ground Size Reduction?

[r_olson_06]

Is there a permitted ground size reduction for an EGC (Equipment Grounding Conductor). I am installing a 2000A 480V Equipment subfeed not a service. So I must size off a EGC not a GEC (grounding electrode conductor). Due to the size of the feed I must parallel the runs and in this case 8 times with 350Kcmil AL. According to the code I am not allowed to parallel the EGC down sizes as the ungrounded conductor. So according to the Table 250.122 I must pull a 400Kcmil Al. Is there any permitted reductions like in GEC 22-1/2 or 12-1/2% rule which ever one it is? The installation is all in EMT but I would like to pull a ground also. Any Help on this issue would be great. I am a little rusty on grounding in the code book.

 

[Aceman]

No, there is not.

Here's some other electrical forums that may help you in the future:

http://forums.mikeholt.com
http://www.electriciantalk.com

 

[sparky36000]

Ace is right, but why are you going with so many parallels with that load? If you went with something like 600MCM XHHW aluminum you could do it with 6 runs of 3" and save 2 400MCM EGC's, not to mention the extra pipe, racks, and labor to install it. How long is your run?

 

[ddawg16]

Ace is right, but why are you going with so many parallels with that load? If you went with something like 600MCM XHHW aluminum you could do it with 6 runs of 3" and save 2 400MCM EGC's, not to mention the extra pipe, racks, and labor to install it. How long is your run?

Some good points......unless there are a lot of elbows along the way.....600 is not the funnest thing to pull.....I just sit back and watch....and it still hurts.....

 

[sparky36000]

Some good points......unless there are a lot of elbows along the way.....600 is not the funnest thing to pull.....I just sit back and watch....and it still hurts.....

If the conduit is run to code, the pull is rigged right and you have a couple apprentices with strong backs and weak minds, it's a piece of cake

 

[r_olson_06]

The run isn't too far about 200' but it still makes fun for bonding all them grounds since most ground lugs are not even remotely close to that size. Thanks for the input.