DIYbanter - View Single Post - What size wiring for Central A/C compressor?

The Daring Dufas[_8_]

On 3/5/2013 12:12 AM, wrote:
On Mon, 04 Mar 2013 22:21:55 -0600, The Daring Dufas
wrote:

On 3/4/2013 10:06 PM, wrote:
On Mon, 04 Mar 2013 20:36:50 -0600, The Daring Dufas
wrote:

And if you look at that table, it shows that 12 gauge is OK for
up to 25 amps. The nameplate on the AC eqpt Mike has says
the minimum circuit ampacity is 24.4 amps. Therefore, 12 gauge
meets the minimum requirement and is permitted.

Did you look at the notes from the table? They are at the bottom of the
table and will show what I use and what the inspectors go by. You will
see a little note reference next to the 25 amp figure. ^_^

Absolutely. That note takes you to 240.4(D) which references 240.4(G)

G) Over current Protection for Specific Conductor Applications. Over
current protection for the specific conductors shall be permitted to
be provided as referenced in Table 240.4(G).

which references 440 part III & IV and 430 part III, IV, V, VI & VII
where we get this permission for larger OC devices and the ability to
use 310.16 at the listed rating.

Like I said, you need to read the whole code, not just the first thing
you see.

I'll defer to you on it then but I'll continue to install what I know
will pass inspection not what I think I can get away with. ^_^

TDD

Whatever you need to do. You are just oversizing wire but as long as
you keep getting the bid, rock on.

You probably should have the conversation tho. I am curious how your
inspectors can ignore that label.

I remember one who would not pass a job unless the HACR sticker was on
the breaker for the AC. It didn't matter what the paperwork from the
manufacturer stated. O_o

TDD