#2 AWG SER cable - 80A subfeed?

[jeff48356]

According to the ampacity table at 310.15, #2 AWG aluminum is good for 75 amps in the 60-degree column, since that's the one we're supposed use when dealing with cables rather than individual conductors. Since 75A is not a standard size, we're allowed to use the next higher breaker, which would be 80A. Is that the proper size breaker when using #2 SER AL to feed a subpanel? Or what would most people usually use?

 

[Dennis Alwon]

In some cases ser may be used at 75C. Look at 338.10(B)(4) in the 2014 but the 2017 Nec unless you use #10 ser then you are good to go at 75C

 

[electrofelon]

, #2 AWG aluminum is good for 75 amps in the 60-degree column, since that's the one we're supposed use when dealing with cables rather than individual conductors.

Note there is no such rule. True some cables are required to be used at 60, but it is not a general rule.