Surge Protector
A potential target for a lightning strike, such as an outdoor television antenna, is attached to the terminal labeled A in the photograph. Terminal E is hooked up to a protracted rod buried within the ground.
Ordinarily, no current can flow between the antenna and also the ground as a result of there's very high resistance between B and C, and conjointly between C and D. The voltage of a surge protector, however, is persistently on top of that required to maneuver electrons through the 2 air gaps.
The result is that electrons go through the lightning arresters rather than traveling on to the television set and destroying it. A surge suppressor could also be a spark gap or could have a block of a conductor like carbide or a philosopher's wool.
Some spark gaps are receptive to the air, but hottest varieties are full of an exactness gas mixture and have a little quantity of material to encourage the gas to ionize once the voltage across the gap reaches a specified level.
Other styles of lightning arresters use a glow-discharge tube (essentially sort of an argonon glow lamp) connected between the protected conductor and ground, or voltage-activated solid-state switches referred to as varistors or MOVs.
Surge Protector employed in power substations ar giant devices, consisting of a ceramic ware tube many feet long and several other inches in diameter, typically filled with discs of zinc oxide.
A safety port on the aspect of the device vents the occasional internal explosion while not shattering the ceramic ware cylinder.
Lightning arresters are rated by the peak current they'll get up to, the number of energy they'll absorb, and therefore the break over voltage that they need to start conductivity.
