The DHC-E 8/10 is actually two models in one - switchable between 7.2 and 9.6 kW via a jumper during installation. The units operates at 240 or 208 volt. The DHC-E has two temperature sensors and one flow sensor which feed their readings into the unit's proprietary microprocessor control. Three heating elements are engaged in stages, achieving the desired temperature. The DHC-E continually monitors the water temperature it produces. DHC-E thankless electric water heaters deliver instant hot water. At 240 volt, the DHC-E 8/10 draws 30 amps at 7.2 kW bad 40 amps at 9.6 kW. The recommended breaker is 40 amp for 7.2 kW and 50 amps at 9.6 kW.