NOTE: We will soon be discontinuing the Delta brand lightning and surge arrestors. They are good products, but they do not compare to the quality and performance of the new line of arrestors by MidNite Solar. If you are planning to use one of these devices on a solar or wind power system, we highly recommend the MidNite Solar brand as a better alternative.
Heavy duty lighting and surge arrestor for DC circuits and applications, such as photovoltaic (solar electric) systems and cathodic protection systems for pipelines. The basic design of the DELTA silicon oxide varistor (SOV) arrestor is a pair of metal electrodes separated by a silicon oxide compound. Under normal conditions, the silicon oxide is a good insulator so that no line current flows between the electrodes to ground. When an excessively high voltage occurs on the electrodes, the high energy electrical field ionizes the silicon oxide, changing it from a compound to silicon separate from oxygen. 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 conduction. The DELTA silicon oxide varistor (SOV) arrestor has no spark gap. Valve arrestors have a spark gap to prevent line leakage current and to determine the sparkover voltage. Since the DELTA silicon arrestor conducts at the ionization potential, no spark gap is needed. This is more effective because spark gaps cause high-intensity voltage spikes which act as surges and damage electrical equipment. The DELTA silicon oxide varistor (SOV) arrestor works equally well in both directions.
Rated for 0 to 500 volts DC
Dimensions: 2-1/4" High, 2-1/4" Diameter
Type of design: Silicon Oxide Varistor
Maximum current: 60,000 amps
Maximum energy: 2000 joules per line
Maximum number of surges: Unlimited
Response time one milliamp test: 5 nanoseconds
Response time to clamp 10,000 amps: 10 nanoseconds
Response time to clamp 50,000 amps: 25 nanoseconds For more information, please see the Delta photovoltaic arrestors page.