alt.engineering.electrical

On Tue, 12 Feb 2008 19:26:21 -0500 Roy wrote:

| Phil - it doesn't matter what we think if the AHJ has some reason why a
| certain wire size should be used instead of another, it's his
| call.....Right....& if you can't convince him your sytem is as sound &
| lasting., well ...... ? I call it as I see it., 10awg for 20-30A, 12awg
| for 15-20A depending on the circuits usage or most likely uses &
| projected modifications.

Not always. The term "AHJ" isn't just an individual; it includes all the
local rules and legislations that adopt and possibly modify the NEC. One
individual inspector can be wrong. Or maybe he can be right. But there
needs to be something in writing for things like "tear out all that 14 AWG
and put 12 AWG in". Normally individual inspectors are not consulted on
work to begin. But local codes are. If the local code says 12 AWG on a
15 amp circuit, then so be it. If that is not the case but an individual
inspector demands it, then he can expect appeals.


| It's rare to find 6awg in any household/apartment kitchen range here in
| nyc., 8awg more likely - Maybe in commercial applications., ranges use
| 6awg., It makes for a good riser too., so if the panel is wired with a
| number 6awg you will have to use an 8awg for this theoretical
| circuit......{*}

That depends on the temperature rating of the cable, and the ambient
temperation correction factor at the bottom of table 310.16. Wiring
in an attic has to consider the ambient temperature of that attic,
which can easily exceed 40C and thus have correction factors of 0.82,
0.88, or 0.91, or even lower. If your cable is rated 90C and the
ambient temperature does not exceed 40C then you can do 8 AWG on a
50 amp range. If it is rated 75C, you can't go above 30C ambient
to us 8 AWG on a 50 amp range. If it is rated 60C, you need to go
to 6 AWG regardless.


| so'., number 14 awg is still good to wire 15A light fixtures., it's
| really not what I'd use for a circuit with any motorized
| appliance.....or where any kind of heating element might come into
| play...Plus, I wouldn't homerun it from the panel., mostly I'd use it to
| tap off a nearby no. 12.., I'd never use it to wire a receptacle/outlet
| unless I new that what was going to be plugged into it fell well under
| the wires ampacity....
|
| But, that's just me., you go on ahead and do it your way, if that suits
| you - I've never had a AHJ or Inspector come after me with a complaint
| or a notice of violation., and believe me I'm available }:)

Actually, I would use 12 AWG for the 15 amp circuit. I'm just arguing
that I've never heard of it as being required by any AHJ, other than it
being in a heat intensive situation. 10 AWG is pushing it as that is
hard to work with. But maybe I'd go with stranged 10 AWG. I am more
inclined to have more separated circuits, such as each duplex outlet in
my kitchen being on its own 20 amp circuit, and those might well get
the 10 AWG treatment (especially so if run in a hot attic). I expect to
have individual separate ovens and cooktops, so I may not have anything
larger than 10 AWG going to the kitchen.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2008-02-12-2235@ipal.net |
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