An arrestor, also known as a surge arrestor, is an electronic device that regulates the voltage on equipment by redirecting large flows of current through an alternate circuit to the earth. By channeling huge surges of power to the ground, arrestors are able to protect electronic equipment and electrical systems that are not designed to handle such high amplitudes of current. As such, they are vital in residential homes, pole-mounted transformers, and utility substations.
Here Are 5 Features of Quality Arrestors
1. Durable and Tough Terminals
First, high-quality arrester terminals are made from materials that will not break or bend during installation. They should last for the life of the arrester and not cause issues, such as partial discharge of current or cross-threading. A good way to find out if the terminals, and the arrester as a whole, are durable is to read through the reports from the manufacturer. Only manufacturers of good arresters will have such data available for their users, usually on their websites. The data needs to be clear, accurate, and easy to understand.
2. Reliable Venting

When an arrester experiences a tremendous surge of current beyond its design capability, it is imperative that it rapidly vents off any internal gases to prevent a short circuit or overload. Porcelain or polymer housed arresters have a high success rate in this regard.
3. High Moisture Resistance
Since arresters require good ventilation as discussed above, high moisture resistance is crucial for their survival, especially in very humid areas.
If you plan on placing your arrestor in an exposed area, check the manufacturer’s reports for proof the arrestor has been sufficiently tested and is both waterproof and able to withstand a variety of other environmental conditions.
Some manufacturers will only carry out the minimum tests prescribed by the Institute of Electronics and Electrical Engineers (IEEE), but others will test their arresters beyond that. Looking through a wide array of manufacturers will help you get the best arresters possible.
4. Good Metal Oxide Varistor Disk
A varistor disk provides over-voltage protection through voltage-clamping. Unlike a variable resistor, whose resistance is manually adjusted, its resistance value can change automatically depending on the amount of voltage coursing through it. This means a good quality disk will not only safeguard equipment against very high voltage but will also last a very long time. The best metal oxide varistor disks are made primarily from zinc oxide.
5. Safety Label
In the early days, when arresters looked very similar, safety labels were implemented to ensure workers installed the right arresters in case a lower-rated arrester was erroneously packed into a higher-rated carton. Good manufacturers have continued adopting this practice by using large labels that are easy to see to prevent dangerous installations and ensure safety for all.
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