This standard covers the requirements for three-phase unit substations for step-down operation in the range of 112.5 kVA through 10 000 kVA at primary voltages of 601 volts through 38 kilovolts. The standard is intended for use as the basis for the coordination of equipment by assisting in the selection of components. A variety of designs for unit substations are possible using various combinations of incoming sections, transformer sections, outgoing sections, and transition (throat) sections. Since the transformer section determines the kVA and voltage capabilities of a unit substation, the ratings of the various types of unit substations are described in terms of transformer capability.
- Sponsor Committee
- PE/SWG - Switchgear
Learn More - Status
- Superseded Standard
- Superseded by
- C37.121-2012
- History
-
- ANSI Approved:
- 2000-01-01
- Published:
- 1988-11-30
- Reaffirmed:
- 2006-11-16
Working Group Details
- Society
- IEEE Power and Energy Society
Learn More - Sponsor Committee
- PE/SWG - Switchgear
Learn More - Working Group
-
SASC-WG_C37.121 - SASC - American National Standard for Switchgear - Unit Substations - Requirements
Learn More - IEEE Program Manager
- Jennifer Santulli
Contact - Working Group Chair
- Darryl Moser
No Active Projects
C37.121-2020
IEEE Guide for Switchgear–Unit Substation--Requirements
The basis for the coordination of equipment in unit substations by assisting in the selection of components is intended as the use of this guide. A variety of designs for unit substations are possible using various combinations of incoming sections, transformer sections, outgoing sections, and transition sections. It is intended that the incoming, outgoing, transformer, and transition sections included in a unit substation meet the basic requirements of applicable industry standards for those sections. This guide covers three-phase unit substations for step-down operation in the range of 112.5 kVA or greater at primary voltages of 601 V through 52 kV.
C37.121-2012
IEEE Guide for Switchgear - Unit Substation - Requirements
The basis for the coordination of equipment in unit substations by assisting in the selection of components is intended as the use of this guide. A variety of designs for unit substations are possible using various combinations of incoming sections, transformer sections, outgoing sections, and transition sections. It is intended that the incoming, outgoing, transformer, and transition sections included in a unit substation meet the basic requirements of applicable industry standards for those sections. This guide covers three-phase unit substations for stepdown operation in the range of 112.5 kVA or greater at primary voltages of 601 V through 38 kV.
No Inactive-Withdrawn Standards
No Inactive-Reserved Standards