Key Takeaways
- Isolating spark gaps protect cathodic protection systems by isolating DC current while still allowing lightning surge current to dissipate safely.
- Equipotential bonding bars tie multiple grounding points together to prevent dangerous voltage differences during a strike.
- Lightning rods provide a preferred strike point, directing current safely to ground rather than through a structure.
- Effective lightning protection typically combines all three components rather than relying on any single accessory.
Lightning protection for industrial facilities, commercial buildings and pipelines typically combines three types of grounding equipment: isolating spark gaps, equipotential bonding bars and lightning rods. Each handles a different part of the problem, and using them together is what actually keeps a strike from becoming a fire, an outage or a safety hazard.
Lightning strikes can severely damage commercial buildings, industrial complexes and pipelines without proper grounding. This guide explains how isolating spark gaps, equipotential bonding bars and lightning rods work together to provide comprehensive lightning protection.
More than 20 million cloud-to-ground lightning strikes occur every year in the U.S. That's almost 55,000 strikes a day. The resulting damage to property can be seen in the annual amount of insurance claims related to lightning: $1.65 billion.
All those lightning strikes causing electrical, mechanical, and structural damage can have disruptive effects on commercial and industrial facilities. However, the damage can be minimized with installation of three types of grounding equipment:
Below we explain the basic functions and benefits of these three grounding accessories, along with some brief info about L-com's newest grounding products. But first we discuss why such equipment is necessary, by summarizing the effects lightning can have on commercial facilities, industrial complexes, and pipelines.
Lightning and Commercial Facilities
- Electrical Systems: Lightning strikes can induce powerful electrical surges that travel through power lines and utility systems. These surges can damage electrical equipment, transformers, circuit breakers, and other components, leading to power outages, equipment failures, and downtime.
- Electronics and Communication: Sensitive electronics such as computers, servers, communication equipment, and security systems can be vulnerable to lightning-induced surges. Even indirect strikes or nearby lightning can induce voltage spikes through power and data lines, causing irreparable damage.
Lightning and Industrial Facilities
- Production Disruption: Lightning-induced power outages and equipment damage can lead to production halts, resulting in financial losses. Manufacturing processes, assembly lines, and automated systems can be affected.
- Equipment Damage: Industrial facilities often use large and complex machinery that can be sensitive to electrical surges. Damage to critical machinery can lead to expensive repairs, replacements, and extended downtime.
- Safety Risks: Lightning strikes can compromise the safety of workers by causing fires, damaging safety systems, and creating hazardous conditions.
Lightning and Pipelines
- Communication and Monitoring: Pipelines often rely on electronic monitoring and communication systems for safe and efficient operation. Lightning-induced surges can damage these systems, leading to disruptions in monitoring, control, and emergency response.
- Corrosion and Erosion: Lightning can accelerate corrosion and erosion of pipelines by creating electrical potential differences along the pipeline's length. This can lead to degradation of the pipeline's material and increased maintenance needs.
Which Accessory Solves Which Problem
As a quick reference, here's how the three grounding accessories map to the problems they solve:
| Accessory | Problem It Solves | Where It's Used |
|---|---|---|
| Isolating spark gap | Isolates DC current (e.g. cathodic protection) while still letting lightning surge current dissipate safely | Pipelines and cathodic-protection systems |
| Equipotential bonding bar | Ties multiple metallic components together at the same electrical potential to prevent dangerous voltage differences | Buildings, industrial complexes, structures with multiple grounded systems |
| Lightning rod | Gives lightning a preferred strike point and a safe path to ground instead of through the structure | Rooftops, superstructures, chimneys, outdoor equipment |
Isolating Spark Gaps
An isolating spark gap equalizes the potential voltage between the high-voltage and low-voltage sides of an AC service, providing a controlled path for equalization currents to flow safely.
How They Function:
Each unit has two electrodes with a small air gap between them. The gap remains open during normal operating conditions. If a dangerous electrical system fault occurs and the voltage exceeds a certain threshold, the air gap ionizes and becomes conductive, short-circuiting the gap and preventing any harmful voltages from posing a risk to personnel. The spark gap also helps prevent lightning damage by diverting the high-energy lightning current away from sensitive equipment or structures.
Benefits:
- Protection: Isolating spark gaps protect equipment and structures from direct lightning strikes by providing a low-resistance path for lightning currents to reach the ground.
- Isolation: By diverting lightning energy away from sensitive equipment, they minimize the risk of electrical damage and operational downtime.
- Maintenance: Isolating spark gaps require less maintenance compared to other lightning protection components, making them a cost-effective solution.
L-com's New Isolating Spark Gaps
Our new isolating spark gaps boast a high current-carrying capacity of 100 kA. Their resilient indoor/outdoor construction keeps them operating in temperatures from -40° F to +176° F (-40° C to +80° C). They are available with or without a wiring kit.
Equipotential Grounding Bonding Bars
In a lightning protection system, "bonding" refers to the process of establishing a low-resistance electrical connection between different metallic components of a system or structure. Such components include structural steel, pipes, HVAC systems, electrical panels, etc. An equipotential bonding bar supports the proper bonding of all elements in a building's or system's grounding system. This bonding keeps them all at the same electrical potential, which means they have the same voltage level.
How They Function:
Equipotential grounding bonding bars are conductive elements connected to lightning rods, down conductors, and other metallic components to establish a consistent electrical potential (voltage) across various parts of a structure. In the event of a lightning strike or other electrical event, the bonding bars help to evenly distribute the electrical energy and minimize potential differences. By keeping all interconnected components at the same potential, the risk of electrical shock, equipment damage, and sparks due to potential differences is greatly reduced.
Benefits:
- Safety: Equipotential grounding bonding bars enhance electrical safety by reducing the risk of electric shock and voltage differences between metallic components.
- Equipment Protection: They help prevent damage to sensitive electronic equipment caused by potential differences during electrical disturbances.
- Fire Prevention: By equalizing potential differences, the risk of sparks that could lead to fires is minimized.
L-com's New Equipotential Bonding Bars
Our new panel-mount equipotential bonding bars come in two models, with 6 or 16 attachment points to suit different sizes of commercial, industrial or pipeline installations. They offer a wide operating temperature range of -40° F to +176° F.
Lightning Rods
A lightning rod, also known as an air terminal, prevents lightning from striking a grounded facility. If a direct strike does occur, a lightning rod safely passes the energy into the grounding system via the overall building lightning protection system. They are often placed at elevated points on a structure.
How they function: Lightning rods are typically installed at the highest points of a structure. When a lightning storm approaches, a lightning rod's pointed tip ionizes the surrounding air, creating a path of least resistance for the lightning discharge to follow. The lightning current travels down the lightning rod and is safely conducted into a dedicated grounding system, which then dissipates the energy into the ground.
Benefits:
- Lightning Diversion: Lightning rods protect structures by attracting lightning strikes and safely guiding the resulting currents away from the building, reducing the risk of damage.
- Preservation of Structures: By providing a clear path for lightning to follow, lightning rods help prevent structural damage that can occur from uncontrolled lightning strikes.
- Safety: They enhance the safety of occupants within the building by minimizing the risk of fire, explosion, or electrical shock resulting from lightning strikes.
L-com's New Lightning Rods
Our new lightning rods safely pass the lightning energy into the grounding system via the overall building lightning protection system. The three new models present options tailored for a single-spire rooftop, a triple-spire rooftop and for direct mounting to a security camera. The rods can be mounted to rooftops, superstructures, chimneys, or outdoor equipment. They are light but strong, constructed from highly conductive aluminum and geometrically designed to maximize effectiveness.
FAQs (Frequently Asked Questions)
What is the difference between an isolating spark gap and a bonding bar?
An isolating spark gap keeps two parts of a circuit electrically isolated under normal conditions while still giving a surge a safe path to ground, whereas a bonding bar permanently ties multiple metallic components together so they share the same electrical potential at all times.
Do I need a lightning rod if my facility already has grounding?
Yes — general grounding and bonding manage where electrical energy goes once it's on the structure, but a lightning rod is what gives a strike a preferred point to hit in the first place, rather than an uncontrolled point on the building itself. The two work together, not as substitutes for each other.
How does an isolating spark gap protect a pipeline?
Pipelines often rely on cathodic protection systems that need to stay electrically isolated from other grounded structures for corrosion control. An isolating spark gap maintains that isolation during normal operation but becomes conductive during a lightning strike or fault, giving the surge current a safe path to dissipate without disrupting the cathodic protection system.
What is an equipotential bonding bar used for?
An equipotential bonding bar ties structural steel, pipes, HVAC systems, electrical panels and other metallic components to a common grounding point so they all sit at the same voltage. This prevents dangerous voltage differences — and the shocks, sparks or equipment damage they can cause — during a lightning strike or electrical fault.
L-com's new grounding accessories are in stock now and available for immediate shipment. All orders on in-stock products placed before 6 p.m. CST weekdays will ship the same day. Need help deciding on the right grounding accessory for your application? Connect with one of our L-com technical experts now. Call us toll-free at 1-866-506-2818, chat with us live, or email us at sales@l-com.com.