Description

The Type PVI & PVN arresters contain the same high-quality metal-oxide varistors used in other Ohio Brass DynaVar arresters which have operated successfully since 1981. They have all the MOV advantages such as high temporary overvoltage capability, contamination resistance, improved surge-duty capability and excellent protective characteristics.

In the unlikely event of arrester failure, violent fragmentation of porcelain is eliminated. Instead, the higher available fault currents may cause splits or tears in the polymer rubber housing while the internal fiberglass wrap restrains the valve elements.

Weight is greatly reduced compared to conventional porcelain-housed designs. Installation is simplified because with the reduced weight, a patented, single housing design can be utilized for all arrester voltage ratings.

The small diameter line end terminal hardware permits closer phase-to-phase and phase-to-ground spacings useful in modern compact substation designs and on mobile transformer applications.

ESP™ Weathershed Material

The arrester housing is made of ESP silicone alloy weathershed material that has been successful in field operations for over a decade. The improved ESP housing resists tracking from surface leakage currents and the housing contour provides exceptional leakage distance. The housing sections are mechanically secured to provide a housing suitable for high pressure hot-washing in locations where contamination is severe and routine station maintenance includes washing procedures. Contact Ohio Brass for recommended procedures.

Construction

The housing consists of one or more molded sections which are mechanically secured into one continuous length for all arrester voltage ratings. The base of the arrester is equipped with a factory installed casting which provides the conventional 8.75 inch diameter bolt circle customarily provided with intermediate and the 10 inch diameter bolt circle for station class surge arresters.

The varistor column is centered and restrained in alignment with tightly woven fiberglass filament strands impregnated with epoxy resin. The interstices between the stranding are filled with a silicone dielectric compound so the design is free of air and moisture. The fiberglass stranding construction provides fault withstand capability in excess of the requirements of IEEE/ANSI C62.11-1999.

Benefits

The PVI and PVN arresters have many additional benefits that are included with the polymer housing.

• A PVI or PVN arrester unit are less than half the weight of an equivalent porcelain-housed arrester. This makes transportation, handling and installation much easier.
• All voltage ratings are of single unit design. Field assembly of stacked units is not required.
• With a reduced diameter of energized line terminal and grading rings, the PVI and PVN arresters reduce space requirements.
• The polymer housing makes the PVI and PVN arresters much safer than porcelain arresters.
• Single-unit, high voltage design provides improved contamination performance over multi-unit designs.
• Closer spacing - Smaller line end casting and smaller grading rings allow closer phase-to-phase spacing.
• Increased creepage - Standard units may fulfill high creep requirements.
• Minimal Internal Atmosphere - Will not "breathe" or leak, eliminates moisture ingress, a cause of arrester failure.

SEISMIC PERFORMANCE

All PVI up to 84kV MCOV, and all PVN up to 152kV MCOV meet IEEE 693 as of 1997 High Performance Level. 0.5g zPA.