What Is a Surge Arrester's Purpose?

The potential for electrical systems to fail can arise from many different electrical surges. These surges can be caused by various sources, but they are all detrimental to electrical systems from a damage and outage standpoint. Surge arresters provide critical protection against electrical surges that ensure the safety of your equipment and increase the longevity of the equipment and reduce the amount of time equipment is out of service due to electrical damage.

What Is a Surge Arrester and What Is Its Purpose?

Surge arresters are electrical devices that protect sensitive equipment, electrical circuits, and other electrical infrastructure from being damaged by over-voltage surges in the electrical system. Surges can be caused by something outside of an electrical system, such as a lightning strike, or can be caused by something that is internal to the electrical system, such as a switching operation. Surge arresters work by redirecting the conductive path of the hazard (the excessive voltage) to the earth where it is dissipated away from the equipment and electrical infrastructure.

In essence, the primary purpose of the surge arrester is to limit the amount of transient over-voltages that occur within an electrical system, thereby maintaining the reliability of your electrical system. In the absence of a surge arrester, critical equipment and services would either not work or would require costly repairs that would impact profitability and productivity of your equipment and services.

How Does a Surge Arrester Work?

When there is an electrical surge resulting in excess voltage flowing through the electrical system, the surge arrester comes into action. The surge arrester creates a low-resistance electrical path for the incident electrical surge to be conducted safely to the ground, dissipating the energy of the electrical surge in the process. After a surge voltage concludes, the surge arrester will go back into its original higher resistance state to permit the electrical grid to return to secure utilization. Surges arresters also have fast response times and are vital components in today’s electrical grids.

Types of Surge Arresters

There are numerous types of surge arresters on the market, and each is suited for different applications and engineering design parameters. The most common types of surge arresters include:

• Distribution-class surge arresters: Characteristically used in distribution systems/table gear designed to protect the equipment in medium- to low-voltage environments.
• Substation-class surge arresters: High-voltage protection for substation and bulk-power operations for critical infrastructure.
• Intermediate-class surge arresters: Devices rated between distribution- and substation-class surge arresters designed specifically for medium-voltage applications.
• Secondary surge arresters: Surge protection devices that provide secondary protection to all consumer level outlying electrical systems, including homes.

To determine which surge arrester would work best for your electrical system will depend on your electrical systems operational voltage requirements and individual protection needs. For instance, a high-voltage substation located in an industrial establishment will benefit from using a substation-class surge arrester, but consumer-grade electrical systems, such as households or small businesses, require only secondary surge arresters for safe operation.

Factors Affecting Surge Arrester Prices

When looking at surge arrester prices, there will be various reasons for price changes, including:

• Cost of construction and materials: Components rated at higher voltages usually correspond to higher costs.
• Arrester type: Metal oxide surge arresters (MOSAs) are the most effective option, but they are also costlier compared to older designs.
• Application: Surge arresters for distribution systems tend to be less expensive than those for substations due to differing capacity needs.
• Quality and certifications: High-quality surge arresters from reputable manufacturers with strong quality assurance and certifications tend to have higher costs, though they often offer greater reliability and durability.

It's always best to purchase the highest-quality product available that fits your budget and safety requirements. High-quality surge arresters come with warranties and tend to have lower total lifetime costs due to better performance and reliability.

FAQs About Surge Protectors

Do I need surge protectors?

Yes, you should use surge protective devices if your equipment is exposed to lightning, power surges, or fluctuations in electrical voltage. This is especially important if you operate in an industrial, commercial, or residential environment that contains sensitive electronic equipment or equipment that is expensive to replace or repair.

What can cause a surge protective device to fail or explode?

Surge protective devices can fail or explode due to extreme over-voltage conditions that exceed their rated limits, manufacturing defects, improper installation, excessive environmental conditions like overheating, or aging materials. Performing regular maintenance and using properly rated devices can significantly reduce these risks.

What happens if I don’t use surge protection?

If electrical devices and systems do not have surge protection, they may experience significant damage during power surges, leading to failures, shorter lifespans, and potential safety hazards like fires. Investing in surge arresters helps ensure the long-term reliability and safety of your equipment while minimizing repair costs.

How to Select the Right Surge Arrester

When selecting the appropriate surge arrester device, you must first determine the voltage rating of your electrical system. You need to know the maximum working voltage of the system, the type of equipment you want to protect, and the potential risks in your environment, such as lightning-prone areas. Consulting with an experienced professional can provide valuable guidance in choosing the right surge arrester for your needs.

Consider the manufacturer's reputation for quality and check for certifications indicating compliance with international standards. A reliable manufacturer can provide dependable and durable products that meet your specific requirements.

Conclusion

Surge arresters are essential for safeguarding electrical systems and infrastructure from power surges. Whether for residential, commercial, or industrial use, these devices play a vital role in ensuring safety, functionality, and longevity for connected equipment. Understanding the purpose, types, and specifications of surge arresters will help you make informed decisions that meet both your protection needs and budget. Remember, investing in a surge arrester is not just an expense—it’s a safeguard for the future of your electrical systems and operations.