Many myths and electrical misinformation posted in here. My first ever post addressed the myth that "circuit breakers trip at 80% of rating." Depending on any of many factors (age, temp, mfg., etc etc) a breaker could trip at 10% or never trip at all. The misinformation gets even worse when discussing conductor loading and ratings. Any breaker in reasonably good condition should easily carry 100% of its rating continuously at temps <= 104 F.
Pop quiz: according to the NEC, what is the ampere rating for #10 type THHN conductor (<=3 conductors in raceway, ambient temperature 86 deg F)?
a) 25A
b) 30A
c) 35A
d) 40A
