IEEE Std C37.20.7 pdf free download

IEEE Std C37.20.7 pdf free download.Testing Switchgear Rated Up to 52 kV for Internal Arcing Faults.
3. Definitions
For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary O,,Iine should be consulted for terms not defined in this clause.”
applied insulation: insulation that is conformal to the shape of the conductor, and bonded to the conductor in such a way that removal requires destroying or otherwise damaging the insulation. Typical examples of such insulations are epoxies or polymers applied by fluidized bed or liquid dip processes that are applied at the factory. Specifically excluded from this definition are tape and all types of boots or slip-on insulation that are field installed and/or removable in the field, and any field-applied spray-on insulation, conformal coatings, or shrink tubing.
arc-resistant switchgear: Equipment designed to withstand the effects of an internal arcing fault as indicated by successfully meeting the test requirements of IEEE Std C37.20.7.
compartment: Portion of a vertical section that encloses a specific component or function separated by metal or insulation barriers.
components: Any device connected to the primary circuit and intended for use within the confines of the switchgear enclosure. Examples include the main interrupting or switching device, voltage transformers, and control power transformers.
current-limiting circuit breaker: A circuit breaker that does not employ a fusible element and, when operating within its current-limiting range, limits the let-through 12t to a value less than the 12t of a half-cycle wave of the symmetrical prospective current.
functional unit: Part of metal-enclosed switchgear that comprises all components of the primary and control circuits that contribute to the fulfillment of a single function.
NOTE—Functional units may be distinguished according to the function for which they are intended, for example, incoming unit or feeder unit.
internal arcing fault: An unintentional discharge of electrical energy in air or insulating gas within the confines of a switchgear enclosure.
internal arcing short-circuit current: The maximum value of the rms symmetrical prospective current applied to the equipment under conditions of an arcing fault for the rated arcing duration specified by the manufacturer.
isolated compartment: A compartment that is physically sealed from the effects of an internal arcing fault in adjacent compartments.
partition architecture: The physical arrangement of barriers or parts of the switchgcar enclosure used for separating one compartment from other compartments, or used to create any venting configurations for pressure relief.
pressure-relief device: Any opening. covered or uncovered, which is designed to exhaust the overpressure from an internal arcing fault from the confines of the switchgear enclosure or specific compartment of the switchgear enclosure.
switchgear: A general term covering switching and interrupting devices and their combination with associated control, instrumentation, metering, protective and regulating devices, assemblies of those devices with associated interconnections, accessories, and supporting structures used primarily in conjunction with the generation, transmission, distribution, and conversion of electrical power.
unit: Part of the vertical section enclosed except for openings for interconnections, control, or ventilation (as applied to low-voltage motor control).
4. Ratings
4.1 General
An IEEE guide cannot mandate or define equipment ratings. This guide is intended to establish a level of performance for the equipment under specific conditions. Although these conditions are not an equipment rating, they are the basis of the equipment evaluation described in this guide and are listed in the ratings clause for convenience.IEEE Std C37.20.7 pdf download.