Introduction
Lightning can cause severe damage to electrical systems during storms. To protect your home or business from lightning, install a lightning arrester. It will guard against the surge that follows. This guide will explore lightning arresters. We will cover their function, features, and importance in protecting your electrical systems.
What is a lightning arrester?
A lightning arrester is a device. It protects power lines and transformers. Its main job is to stop lightning from damaging the electrical system. The arrester redirects the surge into the ground. It prevents it from flowing into the electrical network.
We usually place lightning arresters outside buildings or near critical equipment, like transformers. They are conductive metal spirals. They divert the high-voltage surge.
Lightning Arrester diagram
Key Functions of Lightning Arresters
Redirects lightning surges from power lines to the ground.
Prevents damage to transformers, circuit breakers, and electrical equipment.
Reduces the risk of electrical fires caused by high voltage.
Lightning arresters have different classes. Each is for a specific electrical environment. Class 1 arresters can handle larger surges than Class 2 ones. Choosing the right class is critical. A Class 2 arrester in a high-surge area could fail catastrophically.
Working of lightning arrester
A lightning arrester doesn’t stop lightning from striking your building. Instead, it controls where the excess voltage goes. A lightning strike can cause a high-voltage surge in the power line. The arrester diverts the surge to a safe grounding point.
The arrester connects the high-voltage terminal (power line) to a grounding system. It detects voltage spikes far above the normal range. It provides a path for the excess electricity to safely go into the earth.
This is different from a lightning rod. A lightning rod is a passive conductor. It directs lightning strikes to the ground. But it doesn’t stop the resulting surge from entering your electrical system.
Key Components of a Lightning Arrester
Spark Gap
The spark gap is a key part of many lightning arresters, especially older or simpler ones. It consists of a small gap between two conductive electrodes. Lightning strikes trigger a crucial defense. The arrester’s open gap blocks electricity in calm weather. But surges force it shut, redirecting dangerous voltage earthward. This simple mechanism protects vital systems from nature’s fury. It guards against high-voltage threats. Once the surge is diverted, the gap reopens to return the system to its normal state.
Non-Linear Resistors (Varistors)
In modern lightning arresters, varistors, or non-linear resistors, are crucial. These components can change their resistance based on the voltage level. At normal voltage, they have high resistance. This stops current from flowing through the arrester. Surges trigger a drop in resistance. This unleashes a high-voltage flow through the arrester to ground. After the surge, the varistor’s resistance resets to its baseline. This halts the current. It is then ready to protect against future surges.
Varistors are usually made from zinc oxide (ZnO) or silicon carbide (SiC). These materials handle surges well.
Grounding System
The grounding system is the most critical part of a lightning arrester. It safely dissipates the diverted surge into the earth. A good grounding system stops excess voltage from a lightning strike or surge. It prevents further damage by keeping the voltage from re-entering the electrical system.
Grounding systems typically consist of:
Ground rods: Metal rods that are buried deep in the ground to dissipate the surge.
Ground conductors are wires or cables. They connect the arrester to the ground rod. They provide a path for the electrical current to travel.
Types of Lightning Arresters
There are various types of lightning arresters. Each is for a specific application and environment. Knowing the types of arresters can help you choose the best one for your needs. Below are some of the most common types:
Rod Lightning Arresters
Rod lightning arresters, or Franklin rod arresters, are the simplest lightning protection devices. These arresters consist of a single metallic rod that is mounted at the highest point of a structure. A lightning rod provides a path to the ground. It protects the structure from lightning damage.
The rod arrester is particularly effective in protecting tall buildings and telecommunication towers. However, it’s mainly for protecting the structure, not the equipment. It acts like a lightning magnet. It channels the strike safely into the earth. But, it prevents it from passing through the building’s wiring.
Valve-Type Lightning Arresters
Valve-type lightning arresters are for high-voltage systems. They are common in substations and power grids. These arresters have a series of non-linear resistors and spark gaps. They are connected in series. When the arrester detects a surge, the spark gaps close. This allows the excess voltage to be diverted to the ground.
What makes valve-type arresters unique is their ability to reset after a surge. Once the surge is safely grounded, the non-linear resistors cool. Then, the spark gaps open again. This returns the system to normal. This arrester protects high-voltage transformers, generators, and other critical systems.
Tube Lightning Arresters
Tube lightning arresters are widely used for medium- and low-voltage applications. They protect distribution lines and residential systems. These arresters are made up of hollow tubes filled with a gas or air mixture. A lightning surge increases the pressure inside the tube. This causes a discharge that safely diverts the voltage into the ground.
Tube arresters are simpler and cheaper than valve-type ones. So, they are popular for small-scale uses. However, they are often a one-time-use solution. After a big surge, a tube arrester usually needs replacement. Its effectiveness may drop after the initial strike.
Surge Arresters
Surge arresters are often confused with lightning arresters. They serve a slightly different purpose. Lightning arresters protect against direct strikes. Surge arresters protect electrical equipment from smaller surges and voltage spikes. These are caused by power fluctuations and indirect lightning strikes.
Surge arresters are typically installed in homes, offices, and smaller electrical installations. They clamp down on excess voltage. Lightning’s raw power can devastate electronics. Surge protectors shield your vital gadgets from nature’s wrath. They protect computers, fridges, and HVAC units. These devices weren’t built to withstand a direct strike’s massive voltage surge. But they do protect against power surges that can damage electronics.
Key Features of Lightning Arresters
To effectively protect against surges, lightning arresters must meet certain performance criteria. Here are the key features that define a high-quality arrester:
Breakdown Function: The arrester should break down at a precise voltage. This will allow the surge to divert into the ground. This occurs when the transient voltage exceeds the device’s rated breakdown voltage.
Quick Response: The device must respond instantly to voltage spikes. It must divert the surge before it reaches critical systems.
High Spark-Over Voltage: Surge voltages will trigger the arrester’s conduction. But, they must exceed normal system levels. It remains inactive during typical power frequency operation. This ensures it remains inactive under normal operating conditions.
Durability: The arrester must withstand repeated surges without degrading. It should handle discharges without losing its protective properties over time.
Non-Conductive in Normal Conditions: At normal voltages, the arrester is inert. It allows power to flow. Its non-conductive nature ensures smooth electrical system functioning without disruption.
Materials Used in Lightning Arresters
Lightning arresters are primarily made of porcelain or polymer materials.
Prized for resilience and thermal stability, porcelain remains a time-honored material choice.
Polymer arresters are lightweight. They have excellent electrical properties. They resist cracking or breaking under stress.
Choosing the right material is vital. It affects the arrester’s durability, cost, and performance.
Application of lightning arresters
Lightning arresters can be installed in a wide variety of locations:
Power Grids and Substations: These are key points in the grid. Arresters protect large transformers and other equipment there.
Homes and offices shield electronics from voltage spikes triggered by lightning strikes. Protective measures safeguard valuable equipment against sudden power fluctuations during storms.
Telecommunication Towers: Lightning poses a grave threat to communication gear. Safeguarding this sensitive equipment demands vigilant protection measures. Robust shielding and grounding systems are essential to divert harmful electrical surges. Regular maintenance checks help ensure continued safety against nature’s fierce power.
Solar and wind farms rely on lightning arresters to shield vital components. These safeguards prevent surges from damaging costly inverters and transformers. They ensure smooth power generation, even during storms.
Advantages of Installing Lightning Arresters
There are many benefits to installing lightning arresters, such as:
Protection of Electrical Equipment: Shield equipment from costly damage. Voltage surge protection prevents pricey repairs, safeguarding your investment.
Fire Hazards Prevention: Devices that stop dangerous surges protect vulnerable structures from fire.
Reducing Maintenance Costs: It lowers electrical systems’ long-term maintenance costs by preventing damage.
Electric grids stand firm as tempests rage and bolts streak the sky. Networks endure, defying nature’s fury. Reliability soars, outages plummet. Systems weather the storm, powering on through chaos.
How to Choose the Right Lightning Arrester
Selecting the appropriate lightning arrester depends on several factors:
Voltage Ratings: System voltage dictates arrester rating. Match protection to power level for optimal safety and performance.
Environmental Conditions: Areas with frequent lightning or severe weather need stronger solutions.
Application and Location Specifics: Different locations need different classes of arresters. For example, substations need different arresters than residential areas.
Installation Process of a Lightning Arrester
Installing a lightning arrester is a detailed process that involves several key steps:
Pre-Installation Checks: Check for adequate grounding before beginning work in the designated space.
Step-by-Step Installation Guide: Mount the arrester securely. Ensure it is connected to the power lines and grounded.
Post-Installation Testing: Test the arrester post-installation to verify proper functioning.
Maintenance and Inspection of Lightning Arresters
Even after installation, lightning arresters require regular maintenance to stay in top condition.
Regular Visual Inspections: Check for physical damage or signs of wear.
Performance Testing and Monitoring: Ensure the arrester is working within its designed parameters.
When to Replace a Lightning Arrester: If it fails a test or shows significant wear, it’s time for a replacement.
Conclusion
Lightning arresters are vital. They protect your home or business from lightning surges. These devices prevent costly damage during storms. They intercept the surge and direct it safely into the ground. This reduces fire risk and keeps your property safe.
A pro-installed, high-quality lightning arrester will protect your electrical system. To protect a home or an industrial site, use lightning arresters. There are various types and classes to meet your needs.
Read more: Switchgear
