Delta LA 302 DC lightening surge protector: 0 – 500 Volts DC, 3 Wire, 18" leads
Delta based in Texas, USA, have been the go to surge arrestors for the renewable energy market.
The basic design of the DELTA silicon oxide varistor (SOV) arrestor is two metal electrodes separated by a silicon oxide compound. Silicon oxide is a good insulator. This guarantees that under the normal operating conditions of your PV system, that no line current flows between the electrodes to ground. However When an excessively high voltage occurs on the electrodes, the high energy electrical field ionizes separating the silicone and the oxygen. This compound then changes from a silicone oxide to silicon ion. Since the silicon ion is a good conductor, the high energy current is conducted to ground. When the voltage falls toward normal, the silicon and oxygen recombine, forming silicon oxide and shutting off the connection for the electrodes to the ground.
LA302DC DC Lightning Arrestor: 0 – 500 Volts DC, 3 Wire, 18" leads