Lightning Arrester
A lightning arrester is a device which is used to protect electrical equipment from damage caused by lightning strikes.
It protects against the electrical energy generated by lightning, keeping connected equipment, devices and structures safe.
By providing a low-resistance path to the ground, arresters prevent lightning-induced surges from reaching and damaging sensitive electrical components.
Working of a lightning arrester:
Lightning arresters work on diverting the lightning current away from the protected equipment or structure.
- When lightning strikes or creates a surge in the electrical system, the arrester provides a path of least resistance for the electrical energy to dissipate safely to the ground.
- Doing so prevents the surge from flowing through the connected circuits and damaging them.
Types of Lightning Arresters
- Rod Type or Rod
- ESE (Early Streamer Emission)
- Valve Type
- Hybrid
Can lightning strike backward?
Lightning typically follows a path of least resistance between the ground and a cloud. It’s direction is primarily determined by the electric field between the two.
In most cases, lightning strikes downward from the cloud toward the ground.
Which metal is used as a lightning arrester?
A standard metal used as a lightning arrester is zinc.
It is a device designed to protect structures and electrical systems from the destructive power of lightning strikes.
Working principle of a lightning arrestor counter:
- It works by providing a low-impedance path for lightning surges to safely discharge to the ground.
- The counter has a spark gap or a surge arrester connected between the electrical system and the ground.
- When a lightning surge occurs, the voltage rapidly increases, causing the spark gap to ionize and conduct electricity.
- This allows the lightning surge to flow through the spark gap and safely discharge into the ground.
- The discharge path created by the lightning arrestor counter helps prevent the lightning surge from damaging electrical equipment and causing fires.
- The counter is installed at strategic points in the electrical system to intercept lightning surges before they can reach sensitive equipment.
- It can be used in various applications, such as power transmission and distribution systems, communication towers, buildings, and industrial facilities.
- Lightning arrestor counters are designed to handle high voltages and currents associated with lightning strikes.
- Regular maintenance and inspection are necessary to ensure the proper functioning of the counter and its continued protection against lightning damage.
Difference between lightning arrester and surge absorber:
A lightning arrester, a lightning rod, or a lightning diverter is primarily designed to protect structures from direct lightning strikes. It is commonly seen on rooftops and tall buildings.
On the other hand, a surge absorber, often referred to as a surge protector or a surge suppressor, safeguards electrical devices and systems from voltage spikes or surges that occur due to various reasons, such as lightning strikes, power grid fluctuations, or switching operations.
Is lightning arrester safe?
Yes, they are safe and play a crucial role in protecting structures and electrical systems from the destructive power of lightning strikes.
When a lightning strike occurs, the arrester quickly detects the surge of electrical energy. It creates a low-impedance path to safely dissolve the current. This effectively limits the voltage that reaches the connected equipment, reducing the risk of damage.
Main parts of lightning arrester:
- Terminal Base: It is equipped with a terminal base providing a secure connection to the power system or electrical equipment intended to protect.
- Metal Oxide Varistor (MOV): The main component is the Metal Oxide Varistor, commonly known as MOV. It is a ceramic disk made of metal oxide materials such as zinc oxide.
- Electrode: provides a path for the lightning current to flow into the ground, diverting it from the protected equipment.
- Enclosure: The lightning arrester is enclosed in a housing to protect the internal components from environmental factors such as moisture and dust.
- Grounding Connection: It must be properly grounded to divert the lightning current effectively.
- Surge Counter: this is a simple device that keeps track of the number of surges the arrester has encountered.
- Discharge Gap: In certain types, a discharge gap may be present.
- Insulating Material: such as silicone rubber or porcelain are used in constructing the lightning arrester to provide electrical insulation between the internal components and the external environment or adjacent equipment.
- Surge Diversion Path: The MOV, electrode, and discharge gap combination creates a surge diversion path.
Lightning arrester placing:
They are placed on:
- Height and Elevation
- Coverage Area
- Distance from Sensitive Equipment
- Bonding and Grounding
- Maintenance Accessibility
The capacity of a lightning arrester:
The capacity of a lightning arrester is determined by its ability to handle the magnitude of the lightning current without causing damage.
It is measured in terms of the surge current rating, which specifies the maximum current the arrester can safely divert during a lightning strike.
Voltage rating of lightning arrester:
Common voltage ratings for them include 6 kV (kilovolts), 10 kV, 20 kV, 30 kV, 40 kV, and higher.
The specific voltage rating depends on the characteristics of the electrical system it is made to protect.
Is lightning DC or AC?
It is an example of an electrical current. It is specifically classified as a direct current (DC).DC refers to the flow of electric charge in one direction.
Lightning arresters play a crucial role in safeguarding electrical systems and structures from the destructive power of lightning strikes. By diverting the lightning current safely to the ground, these devices protect against surges that can damage appliances, infrastructure, and human lives. Understanding the working principle, types, installation process, and maintenance requirements ensures their effectiveness. By implementing proper lightning protection measures, we can mitigate the risks associated with lightning strikes and maintain the safety and reliability of our electrical systems.