DC Miniature Circuit Breaker, 2 Pole 500V 40 Amp Isolator for Solar PV System, T
DC Miniature Circuit Breaker, 2 Pole 500V 40 Amp Isolator for Solar PV System, Thermal Magnetic Trip, DIN Rail Mount, DC Disconnect Switch C40. AC has a zero-crossing point, but DC does not, so DC arc is more difficult to extinguish than AC arc, which is why AC circuit breakers can not be used for DC power, and DC circuit breakers can be used for AC power.