Transmission Products (T-1201)

Glossary

Corona: A luminous discharge resulting from ionization of the air surrounding a conductor around which a voltage gradient exceeding a certain critical value exists. Creep: The movement that occurs during the Creep Test of an anchor/pile or pier under a constant load. Damper: Vibration dampers reduce fatigue damage to conductor and static wire caused by wind-induced aeolian vibrations.

GLOSSARY

Design Load (DL): The maximum anticipated service load applied to a pile or pier, comprised of calculated dead and live loads. Also known as Working Load (WL). Discharge Voltage: The voltage level that the arrester clamps to during a surge in kV. Sometimes referred to as IR. Dry Band Arcing: Electrical flashes that occur between wet and dry spots over the contaminated surface of an insulator. E-Glass: Electrical grade fiberglass. The first glass used for high- volt age insulators. EHV Connectors: Connectors designed and manufactured specifically to prevent corona discharge. For use at nominal system voltages of greater than or equal to 345 kilovolts. Some end users also consider 230 kilovolts as EHV.

GLOSSARY Flashover: A disruptive discharge that is capable of breaking the insulation level provided by the air around the insulator, which cre ates an arc between parts of different potential or polarity. Full Tension Connector: Connector capable of withstanding a conductor tensile load equal to at least 95% of the rated strength of the conductor. Helical Extension: A helical anchor/pile component installed immediately following the lead section (if required) to increase the bearing area of the foundation. This component consists of one or more helical plates welded to a central steel shaft. Helical Pile: A bearing type foundation consisting of a lead section, helical extension (if required by site conditions), plain extension section(s) and a pile cap. Also known as a Helical Screw Pile or Helical Screw Foundation. Helical Pulldown ® Micropile: A small diameter, soil displacement, cast-in-place helical pile in which most of the applied load is resisted by the central steel shaft and steel reinforcement, if installed. Load transfer to the soil is both end bearing and friction. The design is protected under United States Patent 5,707,180, Method and Apparatus for Forming Piles In-Situ. Hotline Links: Hardware fittings which include shoulders to accommodate hot line tools. IEC: The International Electrotechnical Commission develops and publishes international standards for all electrical technologies. Inhibitor: A compound used to inhibit the growth of oxides on electrical connection interfaces and to prevent the ingress of contaminants into electrical connection interfaces.

Page 432 | August 2013