The NEC in Alaska
The NEC in Alaska
(OP)
Since resi. insulation temp is fixed at 60℃ to 90℃ and
ampacity is determined by I² and amb. temp.,
can resi. wires and thermally operated CBs in Alaska legally carry more current?
ampacity is determined by I² and amb. temp.,
can resi. wires and thermally operated CBs in Alaska legally carry more current?






RE: The NEC in Alaska
RE: The NEC in Alaska
RE: The NEC in Alaska
While we're on the subject, is 60℃ a nominal value (like a 2x4 is not 2.0" x 4.0") or does the insulation actually reach that temp (I'm hoping the second option is correct)?
RE: The NEC in Alaska
RE: The NEC in Alaska
It might be possible to exceed the table ampacities for installations designed under engineering supervision (as allowed by the NEC) if the engineer responsible has additional information about thermal characteristics or maximum ambient temperatures.
RE: The NEC in Alaska
RE: The NEC in Alaska
RE: The NEC in Alaska
Also you can't use larger than a 20A breaker on 12AWG or 30A on 10AWG, regardless of the numbers in the tables.
Don't forget that it gets warm in the summer, even in Alaska.
New rules in the 2008 NEC have specific temperature adjustments that must be applied to conduits installed on rooftops, due to solar heating.