The 125% rule for branch circuits feeding loads that are considered to be continuous (one that can be on for 3 hours or more). NEC 210-22(c) & 220-3(a), probably other sections as well.
26 amps calculated above x 125% = 33 amps of required branch circuit ampacity.
One way to try to argue your point is to point out that #10 THHN has an actual ampacity of 40 amps, but must not have overcurrent protection of greater than 30 amps. So 80% of 40 amps is 32, which is adequate for a 26 amp load. 80% is just the 125% rule applied backwards. Nevertheless, I believe applying the 125% rule to the 26 amps required will put you into a 40 amp circuit with #8's.
Radar
