I hate to be a spolier, but the #2 al. fed by a 100 amp breaker is only acceptable as SE conductors, or as a feeder which serves as the main power feeder to a dwelling.
I see this violation regularly when 100 amp SE cable is installed as a 100 amp subpanel feeder.
Do the elements operate simultaneously? If so, I think the whole feeder ckt. is underrated.
The effects of low voltage are much more(visibly) noticeable on incandescent lighting because a 10% VD can result in up to a 30% lumen reduction.
