Questions about nec code

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larry wright

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I have a few unanswered questions about the nec code if anyone here can offer an answer.

1. What is the ceiling height of a transformer vault?

2. Where do you find bare copper wire in the code book?

3. What is the kcmil of a #12 bare copper wire?

4. What does 12* copper wire mean and where do you find it in the code book.

Thank you for your time and answers

Larry Wright
 
I think you may want to invest in Mike Holt's book "Understanding the National Electric Code" It wold be an invaluable tool for you. :smile:
 
larry wright said:
I have a few unanswered questions about the nec code if anyone here can offer an answer.

1. What is the ceiling height of a transformer vault?
All the way to the top.

2. Where do you find bare copper wire in the code book?
In what respect are you asking about?

3. What is the kcmil of a #12 bare copper wire?
#12 is the size, equals 6530 CM, same as insulated wire.

4. What does 12* copper wire mean and where do you find it in the code book.
Don't understand this question.

Thank you for your time and answers

Larry Wright
Click to expand...

Follow advice of acrwc10!
 
I have a few unanswered questions about the nec code if anyone here can offer an answer.

1. What is the ceiling height of a transformer vault?
AFAIK the nec does not specify any ceiling heigth. Read section 450. that's wher it will be

2. Where do you find bare copper wire in the code book?
Probably Table 8 is you best source. I've never seen an ampacity listed for bare copper wire - bus bars, yes 366.23; bare wire no. But I have never looked for it.

3. What is the kcmil of a #12 bare copper wire?
Look at table 8 again. 6530kcmil

4. What does 12* copper wire mean and where do you find it in the code book.
I've never seen a reference to "12*"


edit: posted right after barbeer. What he said first.

carl
 
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I dont know if this was what you were asking, but for the question about what 12 means. The 12 AWG, the AWG stands for American Wire Gauge.
 
larry wright said:
4. What does 12* copper wire mean and where do you find it in the code book.
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I find it in T310.16

What is says.....full answers cost $$ :grin: ...but here's a hint ~ think OCPD :cool:
 
If I'm not mistaken, the * after the wire size, in this case 12 AWG is for de-rating purposes, check 310-16, I think and there will be a fine print note as to the markings.
 
chris kennedy said:
I also would like to welcome you to the Forum Larry.

There are no stupid questions only...
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Yeah.... Me too - but the number and type of questions looks like they came off a test? Being a firm believer in 'showing the math' so to speak offers proof of learning, as opposed to thats what the calculator says.... We being the calculator in this case possibly.
 
larry wright said:
4. What does 12* copper wire mean and where do you find it in the code book?
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It's called an asterisk, and it means look for another asterisk. In this case, it's at the bottom of the table, and it says:

* See 240.4(D).
 
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