What is Lightning Arrester?
A lightning arrester, also known as a surge arrester or a lightning diverter, is a device that protects electrical equipment from overvoltage caused by lightning strikes. It works by providing a low-impedance path for the lightning surge to follow, redirecting it away from the protected equipment.
The lightning arrester is typically connected between the power line and the equipment to be protected, such as a transformer or a transmission line. When a lightning strike occurs, the arrester conducts the surge current to ground, preventing it from damaging the equipment.
There are two main types of lightning arresters: the traditional rod arrester and the newer metal oxide arrester. Rod arresters consist of a metal rod or tube mounted on top of a pole or structure, while metal oxide arresters use a ceramic housing filled with metal oxide discs.
Lightning arresters are commonly used in power systems, telecommunications, and other applications where the equipment is at risk of damage from lightning strikes or other overvoltage events.
Ennob specializes in the production of Home Lightning Protection Systems that utilize a combination of copper and aluminum alloys to create a highly conductive pathway to the ground. This system helps to minimize impedance, thereby safeguarding the electrical system from damage caused by fault currents.
Types of a Lightning Arrester
In this article we will discuss some prominent types of lightning arresters and the choice of lightning arresters depends upon the following factors:
Voltage Level: The voltage level of the system being protected will determine the type of arrester needed.
Frequency: The frequency of the system, whether it is a power system or a communication system, will determine the type of arrester needed.
Environment: The location of the system being protected, the weather conditions, and other environmental factors will determine the type of arrester needed.
Some of the prominent types of lightning arresters are:
Rod-type Lightning Arrester
Rod-type lightning arrester is the oldest and most commonly used type of arrester. It consists of a metal rod or tube mounted on top of a pole or structure, which provides a direct path for lightning to ground. The rod is made of copper or aluminum and is usually pointed at the top to facilitate corona discharge, which helps to ionize the air around the rod and create a low-impedance path for the lightning current to follow. The rod is connected to a ground electrode through a conductor, which helps to dissipate the lightning current into the ground.
Horn-type Lightning Arrester
Horn-type lightning arresters have a horn-shaped metal structure that is designed to create a high-voltage gradient that ionizes the air and provides a path for lightning to ground. The horn is connected to a ground electrode through a conductor. When lightning strikes the horn, the resulting discharge ionizes the air and creates a low-impedance path for the lightning current to follow.
Valve-type Lightning Arrester
Valve-type lightning arresters use a series of spark gaps and a valve assembly to provide protection against lightning surges. The spark gaps are connected in series with the protected equipment, and the valve assembly is connected to ground. When the voltage across the spark gap exceeds a certain level, the spark gap breaks down and the valve assembly conducts the surge current to ground.
Metal Oxide Lightning Arrester
Metal oxide lightning arresters are a newer type of arrester that use a ceramic housing filled with metal oxide discs. The metal oxide material has a highly nonlinear resistance that decreases with increasing voltage, providing effective surge protection. The discs are connected in series with the protected equipment, and the assembly is connected to ground.
Hybrid Lightning Arrester
Hybrid lightning arresters combine the best features of rod-type and metal oxide arresters, providing superior protection against lightning surges. The arrester consists of a metal oxide disc connected in series with a spark gap and a rod or tube. The spark gap is designed to break down at a lower voltage than the metal oxide disc, providing an initial low-impedance path for the lightning current. If the surge current exceeds the breakdown voltage of the spark gap, the metal oxide disc takes over and provides additional protection.
Lightning Arrester for Building
Lightning arrester for buildings, also known as a lightning protection system (LPS), is designed to protect the structure and its occupants from the damaging effects of lightning strikes. A lightning protection system typically consists of three main components: air terminals, conductors, and ground electrodes.