Active Standard

IEEE 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.

Sponsor Committee
PE/SWG - Switchgear
Learn More
Status
Active Standard
PAR Approval
2020-02-13
Superseding
C37.121-2012
Board Approval
2020-09-24
History
ANSI Approved:
2022-09-07
Published:
2021-03-09

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
No Active Standards

C37.121-1989

American National Standard for Switchgear - Unit Substations - Requirements

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.

Learn More

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.

Learn More

No Inactive-Withdrawn Standards
No Inactive-Reserved Standards
Subscribe

Stay up to date about new developments, including resources, insights and more.