Tips & News - Spring 2018

Hubbell bushings are available in three technologies: Paper-Oil-Capacitor, Paper-Resin-Capacitor and Solid- Dielectric-Capacitor

developed to provide safer, faster and more cost-effective substation maintenance and testing practices. Most recently, PCORE enhanced the PRC® bushing product line. PCORE introduced an oil-free option for electric utilities that appreciate the proven longterm performance of PRC®s which were first introduced in the 1960s combined with the benefits of an oil-free bushing technology, Fig. 4. Some of the great features of the bushings produced by PCORE Electric and Electro Composites are: • All bushings are IEEE 693 seismically certified • Most designs are suitable for TBI –Transformer/Breaker Interchangeability • Users have the choice between oil-filled or oil-free bushing technologies for 15 kV through 138 kV voltage classes • Availability of high-creep and high altitude bushings as a standard offering • All bushings are fabricated in ISO- 9001 (2008) certified factories • Bushing designs are available for IEEE C57.19.00/01, CSA C88.1 and IEC 60137 standards • Standard configurations and “Engineered to Order”replacement bushing options are available for critical applications

which are well known and widely accepted by the electrical industry. The third more recent technology, known as the SDC™ (Solid-Dielectric-Capacitor) type technology fabricated by Electro Composites, is made of cast electrical grade epoxy resin, which provides different benefits and range of use. All three technologies are capacitance graded; meaning that the internal electrical stress within the insulating core is controlled or graded using series capacitors imbedded within the insulation. The bushing products offered by Hubbell are summarized in Table 1. The range of applications for each of the three bushing types offered by Hubbell is summarized in Fig. 2. Moving Forward In more recent years, the Bushing Business Unit has launched new products based on customer feedback and solutions needed for the industry. Electro Composite’s generator and generator-step-up transformer type bushings for power generation applications provide reliable high-current bushings for new and aging in-service generators and large power transformers, Figure 3. Both businesses provide bushings certified to the IEEE-693 seismic standard to address utilities’ concerns for earthquakes and other major natural disasters. PCORE is the only bushing manufacturer in the world to offer a 500 kV oil-filled, porcelain bushing to meet the high-performance level of this standard. Convenience type products such as Quick- Link type bushings and PCORE Seismically Enhanced Test (SET) Terminals have been

SDC® - SDCTM - SOLID- DIELECTRIC-CAPACITOR • Solid cast epoxy composite bushing technology with integral epoxy sheds and condenser core, providing all the advantages of oil-free technology • Modern bushing technology with 20 years proven field service • Transformer-Breaker Interchangeable (TBI) bushing combined with high performance seismic capabilities • Custom designs to meet difficult dimensional requirements • Available per IEEE C57.19.01, CSA C88.1, IEC 60137 abd DUN 48124 bushing standards

PRC® - PAPER-RESIN-CAPACITOR • Resin-impregnated paper wound core with external porcelain insulator. • Available in both oil-filled and oil-free designs. • Transformer-Breaker Interchangeable (TBI) bushing combined with high performance seismic capabilities • Available per IEEE C57.19.01 andCSA C88.1 bushing standards

POC® - PAPER-OIL-CAPACITOR • Oil-impregnated paper wound core with internal/ external porcelain insulators. • Tried and proven bushing technology with +60 years track record. • Transformer-Breaker Interchangeable (TBI) bushing combined with high performance seismic capabilities. • Available per IEEE C57.19.01 and CSA C88.1 bushing standards.

Figure 1. Available Bushing Technologies

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