Another question with an answer...

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Ok...The minimum size single equipment bonding jumper installed for bonding the metal service nipples for a service lateral of 7 parallel runs of 600 kcmil THWN copper is: Equivelent size? 600 The way it's worded in the code book and the hand book for that matter doesn't suggest 12.5 % of the largest conductor. But that's what I'd like to say. You tell me Sir? If you don't mind....
 

don_resqcapt19

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Illinois
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retired electrician
Ok...The minimum size single equipment bonding jumper installed for bonding the metal service nipples for a service lateral of 7 parallel runs of 600 kcmil THWN copper is: Equivelent size? 600 The way it's worded in the code book and the hand book for that matter doesn't suggest 12.5 % of the largest conductor. But that's what I'd like to say. You tell me Sir? If you don't mind....
The equipment bonding jumper must be run in parallel and sized based on T250.66 and the largest ungrounded conductor in the raceway. 250.102(C)
 
I believe geraldkinen is correct
a single line side bonding jumper to bond 7 pipes that are metallic would be 600kcmil also
250.102c states " where routed with the raceways or cables, shall be run in parallel" and in this case, don_resqcapt19 is also correct 1/0 copper
 

don_resqcapt19

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Illinois
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retired electrician
The code section is not clear on what you do with a bonding jumper that is not routed with the raceways or cables, but it does suggest 12.5% in the first part of the code section.
 
On the question

On the question

The equipment bonding jumper must be run in parallel and sized based on T250.66 and the largest ungrounded conductor in the raceway. 250.102(C)
Thank you sir! I got that.
And the way this question is worded it seems as though they are looking for the single equipment bonding jumper for the answer. And they're not giving me 1/0 for an answer. Multiple choice... And Why would honesty come into question here. Or more to the point being called a thief. That's a mean word
for somebody that truly deserves it. All any man has is his word in life is his word, if you lose that, youv'e gained nothing! My word is my Bond.....
 

JFletcher

Senior Member
Location
Williamsburg, VA
And Why would honesty come into question here. Or more to the point being called a thief. That's a mean word
for somebody that truly deserves it. All any man has is his word in life is his word, if you lose that, youv'e gained nothing! My word is my Bond.....

Not sure if you are serious, but that's in reply to Don's signature - it automatically appears on all of his posts. The part I bolded would make a good sig line too.
 

charlie b

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Seattle, WA
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Electrical Engineer
And Why would honesty come into question here. Or more to the point being called a thief.
You will have to ask Benjamin Franklin that question. Note that Don gives him credit for the quotation, in Don's signature tag.


If you want to add your own signature tag to all your posts, you can do that from the "My Profile" link at the top left of the page.

The text that follows is my own signature tag.
 

augie47

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Staff member
Location
Tennessee
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State Electrical Inspector (Retired) DINOSAUR
I agree with Don that the Code does suggest the 12-1/2% and, in your case, a 600 kcmil would be correct..although difficult to install :grin:
Individually installed 1/0s would be more simple.

I also have found Don's general signature tag to be most true
 

Richardrlr

Member
Location
spring,tx
gronding for parrell feeds

gronding for parrell feeds

the 12% rule for conducters bigger than 1000mcm look at 250-122f-2 size your ground to the largest ungrounded conducter on table 250.66 the egc should carry he full load if a fault occurs on one of runs.
 
When an equipment bonding jumper is installed as a single conductor (in a daisy-chain fashion) it must be sized for the total area of the conductors installed in parallel using Table 250.66 or the 12.5% rule for larger service entrance conductors exceeding 110 kcmil copper or 1750 kcmil aluminum.
So a single bonding jumper for 7 runs of 600kcmil would be 600kcmil (7 X 600,000 x .125 = 525,000 or 600kcmil minimum.
If the equipment bonding jumper is installed individually (seperate bonding jumper to each conduit in parallel) then Table 250.66 shall be used based on the size of the ungrounded service entrance conductor in each raceway.
Individual bonding jumpers would require a 1/0 copper conductor.
 
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