ANSI/IEEE Standard Device Numbers, Suffixes, and Acronyms

Vocabulary practice flashcards covering ANSI/IEEE Standard C37.2-2008 device numbers, protection suffixes, and power distribution acronyms.

IEEE Standard C37.2-2008

The standard specifying North American standard device numbers and added letters used for protective relays in electrical power systems.

Device 1

Master Element

2

Time Delay Starting or Closing Relay

Device 3

Checking or Interlocking Relay

Device 4

Master Contactor

Device 5

Stopping Device

Device 6

Starting Circuit Breaker

Device 7

Rate of Change Relay

Device 8

Control Power Disconnecting Device

Device 9

Reversing Device

Device 11

Unit Sequence Switch

Device 21

Distance Relay

Device 25

Synchronizing or Synchronism–Check Device

Device 27

Undervoltage Relay

Device 32

Directional (Reverse) Power Relay

Device 46

Rev. Phase or Phase–Bal. Current Relay

Device 49

Machine or Transformer Thermal Relay

Device 50

Instantaneous Overcurrent

Device 51

AC Inverse Time Overcurrent Relay

Device 52

AC Circuit Breaker

Device 59

Overvoltage Relay

Device 67

AC Directional Overcurrent Relay

Device 79

AC–Reclosing Relay

Device 81

Frequency Relay

Device 86

Lockout Relay

Device 87

Differential Protective Relay

Device 94

Tripping or Trip–Free Relay