The Importance of Lead Length for Arrester Applications

Posted by Ryan Freeman on Aug 17, 2020 1:00:00 PM

A commonly overlooked consideration in arrester applications is the impact of lead length. The inductance of lead wires can produce an inductive voltage drop which in turn will lower system protection. This voltage drop only occurs if the lead carries surge current and is in parallel with the equipment being protected. This resultant voltage is added to the discharge voltage of the arrester during a surge event, thereby reducing the protective margin of the system. The lead wire’s inductance is not strongly influenced by conductor diameter, but rather of overall lead length. Therefore, care must be taken to keep the lead length to a minimum in both distribution and substation applications.

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Topics: Arresters

Getting Started with Surge Arrester Specifications

Posted by Ryan Freeman on Jun 10, 2020 8:00:00 AM

With the recent and upcoming revisions of IEEE C62.11 and IEC 60099-4 surge arrester standards, writing a technical specification for arresters can be challenging for both new and experienced engineers. Most arrester manufacturers have a dedicated team of engineers who are familiar with the evolving standards and can support the revision and/or creation of arrester specifications.

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Topics: Arresters

Components of a Reliable Polymer Compound

Posted by Haley Engel on Mar 25, 2020 3:20:00 PM

Polymer compounds suitable for electrical insulation can consist of 10 or more ingredients which can be broken down to three major categories. These include the base polymer, fillers which can make up nearly 50% of the total compound, and active additives. Compounding of an elastomer with fillers and additives to achieve the desired results for a given application is critical. The components are carefully selected to enhance field performance and ease of manufacture.

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Topics: Distribution, Arresters

Testing for Polymer Long Term Reliability

Posted by Haley Engel on Mar 19, 2020 11:35:00 AM

After defining the characteristics required of an ideal polymer (link to first blog) housing material, the next step is to develop an appropriate test protocol. Good polymer compounds (link to 2nd blog) used for high voltage insulation should be tested for the ability to resist tracking, erosion, corona, and ultra-violet (UV) radiation exposure to ensure long term reliability. The section below provides a high-level overview of the key test procedures defined to achieve the previously mentioned characteristics. The testing regime, outlined in Table 1, allows various materials to be evaluated and led to the optimum material selection for electrical insulation applications.

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Topics: Distribution, Arresters

Characteristics of the Ideal Polymer for Distribution Arresters

Posted by Haley Engel on Mar 11, 2020 4:15:00 PM

It’s a commonly held belief that the single most important characteristic for insulating materials is hydrophobicity, the ability to shed water or cause water films to bead, breaking up the potential leakage current path. Because the polymer housing is the primary defense for system critical distribution equipment, there are several other important polymer characteristics worth taking into consideration.

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Topics: Distribution, Arresters

How Ground Lead Disconnectors Operate

Posted by Hubbell Power Systems on Oct 17, 2019 8:00:00 AM

Electric utility operating system reliability is an important factor of utility performance. As a common practice, distribution arresters are assembled with a ground lead disconnector (GLD) designed to respond to arrester fault current during a short by detonation of a cartridge inside of the disconnector housing.

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Topics: Arresters

Understanding Distribution Arrester Types for Effective Equipment Protection

Posted by Haley Engel on Jun 4, 2019 8:30:00 AM

There are three distribution arrester types commonly used to protect overhead distribution equipment from the damaging effects of overvoltage. IEEE C62.11 defines Normal Duty (ND) and Heavy Duty (HD) classes by their ability to withstand certain current impulse levels. The third, Heavy Duty Riser is a type, or variation, of the HD classification and utilizes a larger diameter Metal Oxide Varistor (MOV) disc.

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Topics: Arresters

Gapped vs Gapless Distribution Arresters

Posted by Haley Engel on Mar 1, 2019 2:00:00 PM

When comparing different arrester designs, it is important to understand how the arrester was built to correctly evaluate the amount of protection it will provide. The IEEE C62.11 standard covers two types of Metal Oxide Varistor (MOV) distribution arresters that are available today, internally gapped and gapless. These arresters might look identical from the outside, but the different internal module design affects how the arrester protects voltage sensitive equipment.

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Topics: Arresters

Arrester Field Testing

Posted by Ryan Freeman on Aug 6, 2018 2:09:00 PM

All Hubbell Power Systems surge arresters are factory tested according to IEEE C62.11 and IEC 60099-4 routine test requirements. Once in use, surge arresters do not require field testing for routine maintenance. If arrester field testing is desired there are several test options with varying levels of usefulness and convenience.

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Topics: Arresters

Substation Arrester Selection

Posted by Haley Engel on Jun 13, 2018 10:04:00 AM

Surge arresters can extend the life of system assets by limiting the voltage across expensive substation equipment during a switching surge event. Station class arresters must be carefully selected to provide the best protection.

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Topics: Arresters, Substation