This standard covers ratings, construction, and testing of dead-front control switchboards containing but not limited to devices such as switches, control devices, instrumentation, metering, monitoring, alarms, annunciators, protective and auxiliary relays, and regulating devices and accessories. It includes, but is not specifically limited to, switchboards for the control and protection of apparatus used for or associated with power generation, conversion, transmission, and distribution. Types of switchboards may include control, vertical, dead-front, enclosed, dual, or duplex switchboards. Other construction types include control desks, consoles, benchboards, dual or duplex benchboards, fixed rack, cabinet, and swing rack cabinets. It does not apply to industrial controls, communication equipment, switchboards for use on board ships, or Class 1E switchboards for use in nuclear generating stations.
- Standard Committee
- PE/SWG - Switchgear
- Status
- Superseded Standard
- PAR Approval
- 1999-09-16
- Superseded by
- C37.21-2017
- Superseding
- C37.21-1985
- Board Approval
- 2005-06-09
- History
-
- ANSI Approved:
- 2005-10-07
- Published:
- 2005-12-01
- Reaffirmed:
- 2010-12-08
Working Group Details
- Society
- IEEE Power and Energy Society
- Standard Committee
- PE/SWG - Switchgear
- Working Group
-
SA/C37.21 - C37.21 - Standard for Control Switchboards
- IEEE Program Manager
- Jennifer Santulli
Contact Jennifer Santulli - Working Group Chair
- Christo Thomas
Other Activities From This Working Group
Current projects that have been authorized by the IEEE SA Standards Board to develop a standard.
PC37.21
Standard for Control Switchboards
This standard covers ratings, construction, and testing of dead-front control switchboards containing, but not limited to, devices such as switches, control devices, instrumentation, metering, monitoring, protective and auxiliary relays, and regulating devices and accessories. It includes switchboards for the control and protection of apparatus used for or associated with power generation, conversion, transmission, and distribution. It does not apply to industrial controls, communication equipment, switchboards for use onboard ships, or Class 1E switchboards for use in nuclear generating stations, nor does it address human factor considerations. In this standard, dead-front control switchboards are called control switchboards.
Standards approved by the IEEE SA Standards Board that are within the 10-year lifecycle.
C37.21-2017
IEEE Standard for Control Switchboards
Ratings, construction, and testing of dead-front control switchboards containing, but not limited to, devices such as switches, control devices, instrumentation, metering, monitoring, alarms, annunciators, protective and auxiliary relays, and regulating devices and accessories are covered in this standard. It includes, but is not specifically limited to, switchboards for the control and protection of apparatus used for or associated with power generation, conversion, transmission, and distribution. Types of switchboards may include control, vertical, dead-front, enclosed, dual, or duplex switchboards. Other construction types include control desks, consoles, benchboards, dual or duplex benchboards, fixed rack, cabinet, and swing rack cabinets. It does not apply to industrial controls, communication equipment, switchboards for use on board ships, or Class 1E switchboards for use in nuclear generating stations.
C37.21a-2020
IEEE Standard for Control Switchboards--Amendment 1: Control and Secondary Circuits and Devices, and All Wiring
Requirements for control, secondary, and logic-level wiring are addressed in this amendment. It covers wire type, ampacity, and methods for protecting wiring across a hinge.
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.
No Superseded Standards
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