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
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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
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Sponsor Committee
PE/SWG - Switchgear
Learn More About PE/SWG - Switchgear
Working Group
SA/C37.121 - C37.121 - Guide for Switchgear-Unit Substation--Requirements
IEEE Program Manager
Jennifer Santulli
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Working Group Chair
Darryl Moser

Other Activities From This Working Group

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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 About C37.121-1989

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 About C37.121-2012

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.


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These standards are removed from active status through an administrative process for standards that have not undergone a revision process within 10 years.


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