DC disconnect

A DC disconnect is a cirquit breaker that is designed with direct current (or DC) in mind. The main difference between DC and AC is that DC current does not cross 0 several 10's of times per second (50 or 60 depending on where you live), so any 'arc' that occurs when you try to break a cirquit needs extinguishing. An AC rated disconnect used for DC duty will burn up when used at it's rated current, or worse, it will weld it's contacts together and refuse to break the cirquit.

Our system uses two DC disconnects, one small one that disconnects the Solar Panels from the charger cirquit and a second one that disconnects the batteries from the inverter.