
Considered one of the most powerful forces of nature, lightning can wreak havoc on a
Learn More →Considered one of the most powerful forces of nature, lightning can wreak havoc on a system’s infrastructure, sensitive equipment, and electrical systems. Lightning arrestors act as protectors against high voltage strikes. They are vital for protecting buildings, machinery and other systems from the destructive impacts of lightning. This guide will focus on the guiding principles of lightning arrestors, their functions and applications in different industries. From facility managers to engineers and anyone interested in electrical protection systems, this article offers a structure for understanding the importance of lightning arresters for safety and reliability.
A lightning arrestor is a contrivance that protects a system from the damaging effects of lightning by redirecting the surges of electricity to the ground. The arrestor provides a low-resistance pathway, preventing excessive voltage from traversing the system’s components. They are strategically placed along power lines or near transformers, as they deal with high voltage electricity and contain such components as spark gaps or metal-oxide MOVs, which are fast to respond to spikes. These devices only work when temporarily needed, allowing for a normal operational state of the system under steady condition.
In order to optimize their performance and compatibility with the electrical systems, lightning arresters are rated based on several critical parameters. The following are some common values and specifications of lightning arresters:
Nominal Discharge Current (kA): this rating defines the peak current that the arrester is capable of safely discharging during lightning and other transient events. The common value for this rating ranges from 5 kA to 20 kA depending on the use.
Maximum Continuous Operating Voltage (MCOV): Refers to the maximum boundary voltage that the arrester can endure without deterioration for an exceptional period of time and continuous operating conditions. MCOV values are required to be within the bounds of the system’s specifications, which usually fall between 1 kV and 800 kV for different systems.
Energy Absorption Capability (Joules): This capability describes the energy-absorbing ability of the arrester during electrical transients. Higher energy absorption ratings are very essential for systems located at places which experience frequent thunderstorms.
Clamping Voltage: This is the voltage level at which the arrester starts to conduct or divert the surge for the purpose of protecting the downstream equipment and begins to hold it. In most cases, this value should remain within nominal range of set values.
Response Time: Lightning arresters are designed for instant protective response, the response time to switching surge is generally in the nanosecond range which will provide fast protection during transient events.
Environmental Durability: These devices are often exposed to a range of high temperature, humidity, UV radiation, and extreme surrounding conditions during testing to ensure reliability over time for outdoor installations, ensuring long-term dependability.
Field data shows that the newer arresters utilizing metal oxide varistor (MOV) technology can now reduce equipment damage due to surges by almost 95%, thus improving system reliability. In addition, improvements in design have made arresters more reliable in service, increasing the average life to more than 20 years under standard operating conditions.
Here are some important values and parameters that should be evaluated while measuring lightning arresters for different applications:
Nominal Discharge Voltage (NDV): The voltage value the arrester is assumed to handle during routine procedures.
Maximum Continuous Operating Voltage (MCOV): The maximum stress system voltage the arrester can withstand uninterruptedly without physical or operational damage.
Surge Energy Rating: The amount of energy that can be absorbed, measured in joules, for high-energy surge events.
Impulse Current Withstand (8/20 µs Wave): The highest current the arrester can withstand without failing during a standard lightning pulse.
Typical Activation Speed: Typically one nanosecond for these designs, allowing instant system protection.
High Current Impulse (4/10 µs Wave): Defines the range of kA (usually 10-100kA for industrial models) that the extremes the arrester can withstand have to exceed.
Continuous System Leakage Current: The median electron flow through the arrester at nominal voltage levels.
Operating Temperature Range: Typically lies between -40°C to +85°C, given the materials and design.
UV and Weather Resistance ratings for external fittings.
Expected Operating Lifespan under Standard Conditions: 20+ years with minimal deterioration in performance.
Maintenance: Routine checks for operational status and routine visual checks.
Designs range from lighter weight for residential use to heavier duty configurations for industrial use.
Meets or exceeds the requirements for surge protection equipment in IEC 60099-4 and IEEE C62.11.
Surge protection devices are built with the following crucial criteria to maintain optimal performance and reliability:
Rated Voltage (Ur): Typical ranges from 3 kV to 245 kV, satisfying the needs of various electrical systems.
The Nominal Discharge Current (In) is set to an 8/20 μs waveform with a 5 kA rating, 10 kA or higher for heavy-duty industrial applications.
Energy absorption capability: Varible, 4 kJ/kV to 10 kJ/kV system dependent, application dependent.
Max Uc (Continuous Operating Voltage): Generally, 0.8–1.0 of the rated voltage.
Surge arresters give response times in nanoseconds and are able to react to voltage surges or transients almost instantaneously.
The following outlines the specifications along with other detailed information associated with lightning arresters.
Energy Absorption Capacity: 4 – 10 kJ/kV depending on the design and application.
Max Continuous Operating Voltage (Uc): 0.8 to 1.0 times the rated voltage for continuous operation.
Response Time: Reacting to surges and voltage transients typically within nanoseconds.
Rated Voltage (Ur): Defined as the maximum voltage the arrester can safely operate at, in kilovolts.
Discharge Current Capacity: Typically, 5kA to 20kA depending on design and system requirements.
Material Composition: Typically manufactured from metal oxides such as zinc oxide (ZnO) for optimized performance and resilience.
Insulation Material: Porcelain or non-porous polymeric insulation which offers mechanical strength and protection to the ambient environment.
Service Conditions:
Typically, an ambient temperature of -40°C to +40°C.
Altitudes up to 1000m above sea level, unless manufactured to higher altitude specification.
Standards Compliance: Tested and manufactured according to IEC 60099 or equivalent standards.
Environmental Protection Rating:
Outdoors, a minimum of IP65 is required to prevent dust and water infiltration.
In selecting a lightning arrester, these parameters need to be thoroughly considered for effectiveness in terms of purpose and application.
While designing and installing industrial lightning protection systems, the following specifications and data require particular attention:
Surge arresters need to handle expiratory surge energy (energy discharge capacity) with the ability to manage command surge energy. For Indistrual applications, value depends on system voltage and problem level. This value usually ranges for 4 kJ/kV to 10 kJ/kV.
Lightning arresters should have the least possible breach voltage tolerance in order not to harm the equipment. The following values can be used as guidelines:
64 <= x <= 66 kV: Voltage Proportion Loss < 1.5 Rated KLC (‘Base’ In Electronics For Equipment)
66 kV < x < 220 kV: Voltage Proportion Loss < 2.0 Total Unit (KLC)
MCOV can be set in such a way that it obeys operational voltage level, aligning with working voltage of the system. Ranges exemplary include:
MCOV of 22kV Step to 26 kV For Systems < 30 kv nominal voltage
MCOV of 88 kV Set to 108 kV For Systems > 100 kV Nominal Voltage
Surge arresters should possess the ability to withstand strong surge voltage from lightning or switching for any operations, In terms of Walter, typical impulse withstand ratings:
For 11 kV systems, 95 kV peak
For 132 kV systems, 650 kV peak
In this context, devices are tested under sustained overvoltage for thermal stability delay metrics for specific exceedance levels.
Endurance: 10 – 20 seconds.
The failure threshold is usually 25% greater than the nominal operating voltage.
An overview of additional environmental conditions that affect the performance of the arrester:
Humidity Limit: Relative humidity up to 95%.
Wind Load Resistance: Pole-mounted structures withstand winds up to 50 m/s.
These defined values are critical in guaranteeing the protection and safe functional lifetime of equipment in the industrial lightning protection systems. Systematic testing and compliance with defined norms ensure dependability for varying conditions of functioning.
Thorough lightning protection for antennas mounted externally relies on meticulous testing and meeting defined criteria. Below is the important data.
Effective Surge Current Capacity:
Nominal value: 100 kA (8/20 µs waveform)
Maximum surge withstand capacity guarantees saftey during extreme lightning strikes.
Voltage Protection Level:
Max coaxial cable interfaces clamping voltage is ≤ 600V.
Guarantees safety for the protected devices by voltage limiting.
Response Time:
Typical time to react is < 5 nanoseconds (ns).
Ensure low equipment exposure lightning surge delay.
Operating Frequency Range:
Compatible frequencies are DC to 3GHz.
Covers a wide range of telecommunications and broadcasting purposes.
Insertion Loss:
Max. insertion loss is ≤ 0.3 dB at the working frequency.
Boosts protection offered without compromising the signal integrity.
Permissible Climatic Conditions:
Temperature: -40°F to +158°F (-40°C to +70°C)
Relative humidity tolerant up to 95%.
Observes N-type, SMA and BNC connectors.
Complies with diverse antenna configurations.
Adaptable to vertical and horizontal pole wall mounting.
Withstands strong winds and other environmental forces.
Fundamental assessment of these parameters check that lightning protection solutions fulfills the challenging requirments of the industry and guarantees reliable operational performance in the field.
Grounding is an essential aspect in the safeguarding and effectiveness of lightning protection systems. Effective grounding ensures that the flow of electrical energy will be diverted safely into the earth and will minimize capricious destruction to equipment, reliability of operations, and enhance operational dependability. An effective and reliable grounding system will limit possible lightning surge damages to both structures and the people through safe connections of bolts to conductors.
The protection and proper functioning of RF and ham radio systems depends, infrequently, on appropriate grounding and RF interference filter intuition of the system. These practices do not only mitigate damage to the equipment, but also mitigate harmonics distortion and EMI on system performance. Below are some methods most commonly adapted in practice:
Explanation: Single-point grounding is a phenomenon where a single reference point is established for the entire system. It enhances simplicity of the wiring system which is favorable for avoiding ground loops.
Data: Research indicates that single-point grounded systems can achieve up to 70% reduction in EMI underperformed with other inadequate grounding systems.
Description: This technique aliases all_ potential conductive constituents of the system into the same ground potential.
Measurement Standards: For ham radio systems, the measurement of multi-ground bonding resistance set by IEEE standards is optimally less than 5 ohms.
Description: Rods used for grounding are normally made of copper or galvanized steel and are deepened into the ground to provide a low resistance stoop to dissipate surge energy.
Data: It is recommended that a properly installed ground rod should earth less than 25 ohm of resistance as recommended nationally by the National Electrical Code (NEC).
Description: Overvoltage event impacts between the antennas, the radios, and the power systems slashed through surge protection devices.
Efficiency Data: High-quality surge protectors can swerve up to 99% energy diversion from transient energy caused by lightning striking.
Implementation of these recommendations combined with systematic checks of the grounding systems will help mitigate the exposures RF and ham radio operators face while achieving optimal reliable communication.
In the preservation of delicate electronic circuitry from transient voltage spikes, a gas discharge tube (GDT) plays a significant role in the lightning protection systems. A GDT consists of a sealed container, filled with inert gas which becomes conductive when a certain high voltage level is accomplished. During an overvoltage event, the GDT ionizes the gas protective and offers a low-resistance path to ground, diverting the surge while safeguarding the equipment to transform the connected equipment.
Modern gas discharge tubes (GDTs) have proven to be more reliable than their predecessors. For example, it is believed to have response times in the order of nanoseconds and can peak current rated as being several kiloamperes, showing their efficiency in dealing with high power RF systems. In addition, their size and ability to withstand consistent surges without degrading them makes them ideal for dealing with robust surge protection demand. To ensure the optimal functioning of the GDT and the whole lightning protection system, the regular monitoring and maintenance of all system components is recommended.
N connectors are critical in sustaining certain standards in a coaxial lightning protection system. Their overall strapping design permits optimal signal transfer even under harsh environmental conditions. Moreover, their moisture and dampening attributes guarantee optimal performance with minimal recalibration needed. Furthermore, reliability in high-frequency lightning protection applications is essential for seamless operation, especially where dependability is required. In addition, these N connectors boost system dependability by mitigating signal degradation and providing steady impedance preservation.
The very first step to taking care of your surge protector needs is ensuring that it meets all of your individual specifications based on critical performance along with other parameters. The factors and data points that need to be reviewed are detailed below.
Voltage Protection Rating (VPR)
VPR indicates the maximum limit of voltage of surge that can be allowed to pass through to your equipment. Protection Increase is inversely proportional to VPR. For example:
Residential-grade devices typically have VPR ratings between 330V and 800V.
Industrial-grade surge protectors frequently offer ratings below 500V for enhanced protection.
Maximum Continuous Operating Voltage (MCOV)
This parameter defines the maximum voltage that will be continually imposed on the device without system failure. Surge protectors with MCOV rating greater than the nominal system voltage tend to preform much more reliably. For instance:
Standard MCOV values range from 120 VAC to 480 VAC, depending on the application.
Surge Current Capacity is defined as the maximum current that can be diverted at the time of transient surge and limit setting. High levels are crucial for areas that experience frequent or high surges. These commonly include:
10 kA to 40 kA for residential applications.
40 kA to 200 kA for commercial and industrial applications.
During response time, protection from transient voltage phenomena is achieved. The majority of modern surge protectors function in the nanosecond range (< 1 ns) of time to mitigate damage.
Ensure that the selected surge protector complies with the following specifications:
UL 1449, which sets provisions for standard safety and performance testing.
IEEE C62.41, which classifies surge testing.
By considering these specific parameters, you will match them with the operational features of your systems and thus make an educated selection of a surge protection product that offers a tailored solution to your concerns.
When dealing with systems between 0 to 6 GHz, other than having basic components in hand such as the clock signal generator, system components have to be chosen in a way as to minimize signal loss and optimize performance. The most important ones are:
Impedance Matching: A stable value of impedance equal to 50 ohms should be maintained for all the components to minimize signal reflection and ensure maximum transfer of power.
Insertion Loss: The coaxial cables and their connectors should have low insertion loss to maintain signal quality over long distances.
Shielding Effectiveness: The cables should have high electromagnetic field shielding effectiveness.
VSWR (Voltage Standing Wave Ratio): A low VSWR should be targeted.
Power Handling: Confirm that the components fulfill the power requirements of your specific application.
Achieving RF performance that meets industry standards, alongside other operational considerations, facilitates reliability at 0 to 6 GHz.
A: A lightning arrester works by protecting electrical equipment by short circuiting the high vogue on a electric surge caused by lightning it prevents direct strikes from damaging the infrastructure by controlling the paths the electric energy would take.
A: A lightning arrester protects two way radios by intercepting the voltage surge and grounding the voltage surge so that it does not touches the sensitive components. This would assist to abate the damage to the circuitry on the radio ensuring that the communication is functional.
A: The different types of arresters would include the station class intermediate class and distribution class arresters. Each type is made for certain purposes and the devices which are supposed to be relied on voltage surge on the devices and electric networks.
A: Although lightning arresters can protect a variety of electronic devices such as amplifiers and communication devices, they cannot do it alone, and therefore must be included in an overall strategy for surge protection. Their level of installation and upkeep determines how well the device actually works.
A: The response time of an arrestor is critical to arresting the device’s breach surge energy which may threaten vital equipment. Moreover, it reduces the prospective destructive value of high voltage currents.
A: Physical inspection of lightning arresters for any damage, collection of functional connection tests, and performance tests of the lightning arresters operational integrity are all part of the Regular Maintenance Check. This is meant to help protect against surges of voltage and direct hits.
A: Although both lightning arresters and surge protectors share some functions, their specific uses greatly differ. The former protects against high voltage energy surge strikes whereas the latter is used to protect from lower voltage energy surge typical to electric grid oscillations.
A: Considerations involve choosing lightning arresters with greater capacity to handle energy in areas experiencing frequent thunderstorms alongside installing such devices at strategic locations to electronically protect against direct lightning hits.
A: True. Protective devices like surge protectors and grounding devices enable lightning arresters to offer wider coverage against electric surges and primary hits.
Dadao (DDKJ), located in Shanghai, China, is a company that designs and manufactures intelligent systems for electric power distribution automation at high and low voltages. They make such things as energy meters, switchgear devices and industrial automation products which are used across different sectors like power, mining and petrochemicals. DDKJ seeks to provide solutions that work with the help of their global partners by being innovative, producing goods of high quality and offering customer support.
Considered one of the most powerful forces of nature, lightning can wreak havoc on a
Learn More →A hygrometer is a scientific instrument used to measure moisture content, or humidity, within the
Learn More →A hygrometer is a scientific instrument used to measure moisture content, or humidity, within the
Learn More →WhatsApp us