OVERHEAT PROTECTION: All units come equipped with automatic resetting type limit controls to de-energize the heater should an over-temperature situation occur. FAN and MOTOR: Totally enclosed, single phase, permanently lubricated, thermally protected motors with unit bearings on 3 KW - 10 KW models...
And yeah, I don't know where you'd be using 10kW+ for, that's light-industrial processes like a machining center, induction heater, etc. Which, would be pretty badass applications, but that's also quite a big solar panel to keep it supplied on a day-to-day basis? Would be interest...