This guide covers three-phase alternating current (ac) systems from 1 kV to 800 kV. The guide provides recommended electrical operating, safety clearances, and insulation levels in air-insulated electric supply substations. The guide addresses insulation coordination procedures and provides design procedures for the selection and coordination of the insulation levels within the station as they relate to substation clearances. Furthermore, the guide addresses how reduced clearances in high voltage ac substations allow for compact bus arrangements and substation voltage uprating applications. This guide addresses insulation coordination procedures, including the choice of insulation levels and arrester specification, in limited detail and only as relevant to clearance requirements. Detailed and expanded coverage of insulation coordination procedures is provided in other ANSI and IEEE guides and standards (see Clause 2). This guide focuses on open-air bus assemblies and configurations and excludes apparatus clearances (i.e., bushing clearances for transformers, and breakers). Detailed coverage of apparatus clearances is provided in other applicable guides and standards.
- Standard Committee
- PE/SUB - Substations Committee
- Status
- Active PAR
- PAR Approval
- 2025-05-28
- Superseding
- 1427-2020
Working Group Details
- Society
- IEEE Power and Energy Society
- Standard Committee
- PE/SUB - Substations Committee
- Working Group
-
WGD1 - WGD1 - Recommended Clearances and Insulation Levels in Substations
- IEEE Program Manager
- Patricia Roder
Contact Patricia Roder - Working Group Chair
- Chunming Ma
Other Activities From This Working Group
Current projects that have been authorized by the IEEE SA Standards Board to develop a standard.
No Active Projects
Standards approved by the IEEE SA Standards Board that are within the 10-year lifecycle.
1427-2020
IEEE Guide for Recommended Electrical Clearances and Insulation Levels in Air Insulated Electrical Power Substations
This guide, covering three-phase ac systems from 1 kV to 800 kV, provides recommended electrical operating, safety clearances, and insulation levels in air-insulated electric supply substations; addresses insulation coordination procedures; provides design procedures for the selection and coordination of the insulation levels within the station as they relate to substation clearances; and addresses how reduced clearances in high-voltage ac substations will allow for compact bus arrangements and substation voltage uprating applications.
These standards have been replaced with a revised version of the standard, or by a compilation of the original active standard and all its existing amendments, corrigenda, and errata.
1427-2006
IEEE Guide for Recommended Electrical Clearances and Insulation Levels in Air Insulated Electrical Power Substations
This guide, covering three-phase ac systems from 1 kV to 800 kV, provides recommended electrical operating and safety clearances and insulation levels in air-insulated electric supply substations; addresses insulation coordination procedures; provides design procedures for the selection and coordination of the insulation levels within the station as they relate to substation clearances; and addresses how reduced clearances in high-voltage ac substations will allow for compact bus arrangements and substation voltage uprating applications.
These standards have been removed from active status through a ballot where the standard is made inactive as a consensus decision of a balloting group.
No Inactive-Withdrawn Standards
These standards are removed from active status through an administrative process for standards that have not undergone a revision process within 10 years.
No Inactive-Reserved Standards