A surge arrester, which is also called a surge protector or lightning arrester, is a device applied in power distribution systems to protect electrical equipment, such as transformers circuit breakers, or capacitors, from over voltage transients, such as lightning strikes or switching surges. It could be installed in a electrical panel or mounted on the overhead pole. The main purpose of a surge arrester is to limit voltage spikes and divert excess energy safely to the ground, preventing damage to electrical equipment in power distribution systems.
Under the normal voltage conditions, the surge arrester is not conductive, which does not affect normal operation of the power distribution system.
When the system voltage exceeds the maximum continuous operating voltage MCOV of a surge arrester, it becomes conductive, which provides a low resistance path for the surge current to flow to ground to bypass the sensitive devices.
Once the surge has passed, the current in an electrical circuit turns to normal. And the arrester turn back to low conductivity to prepare for next surge occurs.
