WHAT IS A SURGE ARRESTER (PARAFUDR) AND WHAT ARE ITS TYPES?
Surge Arrester (Parafudr) is the general name for products that ensure sudden overcurrents, which are inevitable on phases especially during lightning events, are short-circuited to the ground.
The information that surge arresters “transmit overvoltages to the ground” is not compatible with physical reality. This is because voltage cannot be transmitted from one place to another; it is the electromotive force representing the potential difference between two ends of a conductor.
Current is transmitted from one direction to another thanks to the potential difference between the two ends of the conductor. In a lightning event, surge arresters are necessary to prevent systems from being damaged by facilitating the electron exchange between the ground and clouds.
To prevent the resulting overvoltages, the use of new generation surge arresters is required. In this article, we explain what a surge arrester is, provide basic information about its types, and discuss new generation surge arresters.
What Are the Types of Surge Arresters?
Surge arresters are available separately for high voltage, medium voltage, and low voltage systems. Low voltage surge arresters are divided into three categories: Class B, C, and D.
Class B surge arresters are used at the outermost point of the structure, before the meter. They have the lowest sensitivity and the highest instantaneous overcurrent transmission capacity. Provided that the voltage is less than 1.5 kV and for multiple (10/350us) events, it can safely discharge a total of 125 kA for a three-phase system (25 kA per phase-ground and 50 kA for neutral-ground).
Class C surge arresters are installed after the meter. They ensure that instantaneous overcurrents that Class B could not transmit are directed to the ground with more sensitive protection. Provided the voltage is less than 1.5 kV (8/20us), it can safely discharge a total of 40 kA for a three-phase system (10 kA per phase-ground and 10 kA for neutral-ground).
Class D surge arresters are preferred for more sensitive protection by targeting specific electronic products. Provided the voltage is less than 1.5 kV (8/20us), it can safely discharge a 6 kA current once.
How is a Surge Arrester Connected?
Surge arresters are connected in parallel to the systems. Parallel cables (from 16mm² to 35mm²) taken from the outputs of the phases are connected to the phases of the surge arrester. In some models, a parallel cable is also taken from the system’s common neutral and connected to the neutral input. Finally, the assembly is completed by connecting the cable from the ground output of the surge arrester to the system’s grounding line.
Surge Arrester Prices
Surge arresters are priced according to their Class (B, C, or D) and their poles. Brand reputation also plays a major role in pricing.
Class B 4-pole surge arresters from a reputable brand have a sales price of around 2500 TL, with cartridge prices around 500 TL.
Class C 4-pole surge arresters from a reputable brand have a sales price of around 900 TL, with cartridge prices around 200 TL.
Class D 2-pole surge arresters from a reputable brand have a sales price of around 300 TL, with cartridge prices around 100 TL.
New Generation Surge Arresters
New generation surge arresters are smart devices that can perform protection functions across all low voltage classes. They are protection products that ground the resulting overcurrent and dampen the overvoltage during instantaneous overvoltage situations between the two ends of a system.
New generation surge arresters have dual-action protection capabilities: they prevent overvoltage formation by damping the overvoltage, and they ensure grounding if the overcurrent reaches uncontrollable levels.
Another important feature of new generation surge arresters is their ability to work even without grounding. The search for grounding resistance and ideal grounding, which is a critical detail in traditional applications, is not required in new generation surge arrester applications.
If grounding exists, it must be connected to the new generation surge arresters; this is the only way to prevent ground-side surges from damaging the devices. However, if there is no grounding in the system, application is still possible, and the device will fulfill its protection function.
New generation domestic surge arresters have met with users under the Trimbox brand, with a 87.64% domestic production rate.
Simple precautions sometimes save lives. The best investment we can make for our family, our business, and our environment is protective measures. With Trimbox and GNDSeries, you can be protected from electricity-related damages and resulting electrical contact fires.
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