IEEE PC37.68

standard by IEEE,
IEEE Draft Standard Design, Test, and Application Requirements for Microprocessor-Based Controls of Distribution Padmount, Dry Vault, Wet Vault, and P
Category: IEEE

~~$58.00~~ $29.00

Description

Full Description

Scope

This standard presents basic requirements for the design, testing and application of microprocessor-based controls of distribution switchgear rated above 1 kV up to and including 38 kV. The standard is intended to mitigate the effects of the harsh environments which may be encountered outside the protections provided by a typical substation. This standard applies to microprocessor-based devices employed in distribution switchgear typically mounted on power poles, in wet or dry vaults, or in pad mounted switchgear enclosures. This standard also does not apply to microprocessor-based devices employed in high voltage circuit breakers (IEEE C37.04 "Standard Rating Structure for AC High-Voltage Circuit Breakers") or metal-enclosed switchgear (IEEE C37.20.2 "Standard Metal-Clad Switchgear" and IEEE C37.20.3 "Standard for Metal-Enclosed Interrupter Switchgear"). This standard does not invalidate any tests performed on power system protective relays which are designed to IEEE C37.90 ("Standard for Relays and Relay Systems Associated with Electric Power Apparatus"). Lastly, this standard will not cover the design of the control enclosure such as mounting, latching, or user accessibility.

Purpose

Distribution switchgear is typically mounted on power poles, in wet or dry vaults, or in padmounted switchgear enclosures, and is used with overhead and underground electric utility distribution lines. The evolution of distribution device controls from hydraulic and the electro-mechanical to microprocessor-based has also led to the controls being mounted on power poles, in padmounted switchgear, and in vaults. These locations expose the microprocessor-based controls to the harsh environmental, mechanical and electrical conditions of the electric utility distribution lines. The apparatus used for overhead pole applications and for padmounted applications is typically subject to adverse environmental conditions, such as high winds, potentially heavy precipitation, high solar radiation levels, and extreme ambient temperatures (very high and very low). Furthermore, these installations may be exposed to extreme voltage disturbances, both due to lightning surges in areas of high lightning activity and from switching surges. Apparatus used for vault applications are typically subject to moisture (and possibly submersion); users must address the difficulty in locating and connecting the control, protecting the control cables and connections, and in providing adequate grounding. These installations may have marginal (or no) auxiliary voltage supply and may be subject to extended durations of voltages below the normal operating range. This standard offers design, testing, and application measures, that are appropriate to the special conditions of use of microprocessor-based controls devices. The intent of these measures is to improve the reliability and extend the life of the controls.

Abstract

New IEEE Standard - Active - Draft. Basic requirements intended to mitigate the effects of the harsh environments encountered by microprocessor-based controls of distribution switchgear rated above 1 kV up to and including 38 kV are covered. Basic requirements include the design, testing and application of microprocessor-based controls. Microprocessor-based controls covered by C37.68 are intended to be applied in distribution switchgear which is normally mounted on power poles, in wet or dry vaults, or in padmounted switchgear enclosures