[1electron]

Where can I find the electrical wire sizes for 150 Amp, 200 Amp, and all other amp services, in the National Electrical Code book?

[tkrussell]

The typical chart is table 310.16, for three wires in a raceway or cable.

This list the various types of insulations, and temperature rating of equipment, and the ampacities for each wire.

If the service is for a home, then refer to Section 310.15 (B)(6) and Table 310.15 (B)(6).

[Stratmando]

Tk answered your question. 2/0 for 200 Amp, 1/0 for 150 Amp. Can reduce neutral 1 size.
Example: 2-2/0, and 1-1/0

[ballengerb1]

Could either of you attach table 310.16 from the code? I can't seem to get inside. I have found othe schedules in the past, wrong ones, and would like to print out table 310.16.

[Stratmando]

Don't have scanner hooked up at moment. Hopefully Tk can provide Ampacities Table.
You say you can't get inside? Book? CD? It is in NEC's code book.
Hey, just found this link:

Coastal Electric - NEC Table 310-16

[tkrussell]

Ball, can you access the code from the link I have in the sticky note "Read This First"? I have checked it and it works fine for me. It is what I use to access the code, since all I need to do is click, how lazy am I.

Strat, can you direct me to the section of code that allows reduced neutral, without doing the calcs for unbalanced current?

[ballengerb1]

I'm slow, where is the sticky note? I don't see anything. That other chart I had apparently is a wire manufactures chart showing what they say a wire can handle, not what code says is appropriate for construction. Its in the garbage now.

[tkrussell]

OK, at the first page of the Electric and Light Forum, second post down is the Read First sticky. In it very near the first paragraph is a link to the 2005 NEC, directly from NFPA. You need to do a few clicks, through the agreements and warnings, and you cannot print from the page once the code does appear, at least I have not figured out how, since the code is copyright protected.

Let me know if you have any problems getting there.

[Stratmando]

TK, You are right, I just never figured one where I couldn't. I shouldn't assume.

[tkrussell]

OK thanks, just wanted to be clear and accurate for the DIY'ers, and I am always willing and ready to learn something new.

Reducing the neutral for a feeder is always allowed, however, really only can be done if the calculations for determining the unbalanced current of a service, or panel. While I do agree that most times a reduced neutral will work just fine, and within tolerances, there is always that one special case that we may miss or someone receiving advice may take and be that special case, and overload a reduced neutral.

Just striving to be as accurate as possible.