ANSI Device Numbers
Encyclopedia
In the design of electrical power systems
, the ANSI
Standard Device Numbers (ANSI /IEEE Standard C37.2) denote what features a protective device supports (such as a relay
or circuit breaker
). These types of devices protect electrical systems and components from damage when an unwanted event occurs, such as an electrical fault. Device numbers are used to identify the functions of devices shown on a schematic diagram. Function descriptions are given in the standard.
ANSI/IEEE C37.2-2008 is one of a continuing series of revisions of the standard, which originated in 1928.
Device numbers may be combined if the device provides multiple functions, such as the instantaneous/time-delay AC over current relay denoted as 50/51
For device 16, the suffix letters further define the device: the first suffix letter is 'S' for serial or 'E' for Ethernet. The subsequent letters are: 'C' security processing function {i.e. VPN, encryption}, 'F' firewall or message filter, 'M' network managed function, 'R' router, 'S' switch and 'T' telephone component. Thus a managed Ethernet switch would be 16ESM.
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
, the ANSI
American National Standards Institute
The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...
Standard Device Numbers (ANSI /IEEE Standard C37.2) denote what features a protective device supports (such as a relay
Relay
A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal , or where several circuits must be controlled...
or circuit breaker
Circuit breaker
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...
). These types of devices protect electrical systems and components from damage when an unwanted event occurs, such as an electrical fault. Device numbers are used to identify the functions of devices shown on a schematic diagram. Function descriptions are given in the standard.
ANSI/IEEE C37.2-2008 is one of a continuing series of revisions of the standard, which originated in 1928.
Suffixes and prefixes
A suffix letter or number may be used with the device number; for example, suffix N is used if the device is connected to a Neutral wire (example: 59N in a relay is used for protection against Neutral Displacement); and suffixes X,Y,Z are used for auxiliary devices. Similarly, the "G" suffix denotes a "ground", hence a "51G" is a time overcurrent ground relay. Suffix numbers are used to distinguish multiple "same" devices in the same equipment such as 51-1, 51–2.Device numbers may be combined if the device provides multiple functions, such as the instantaneous/time-delay AC over current relay denoted as 50/51
For device 16, the suffix letters further define the device: the first suffix letter is 'S' for serial or 'E' for Ethernet. The subsequent letters are: 'C' security processing function {i.e. VPN, encryption}, 'F' firewall or message filter, 'M' network managed function, 'R' router, 'S' switch and 'T' telephone component. Thus a managed Ethernet switch would be 16ESM.