ANSI Device Numbers

The ANSI Standard Device Numbers [ [http://www.geindustrial.com/pm/notes/ref/ANSI.pdf GE Multilin - ANSI Standard Device Number] ] ["Protective Relaying Manual", Pennsylvania Electric Association (1975)] [ [http://www.basler.com/downloads/ANSI_functions.pdf Basler Electric - ANSI/IEEE Device Numbers] ] 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.

List of Device Numbers

*1 - Master Element
*2 - Time Delay Starting or Closing Relay
*3 - Checking or Interlocking Relay
*4 - Master Contactor
*5 - Stopping Device
*6 - Starting Circuit Breaker
*7 - Anode Circuit Breaker
*8 - Control Power Disconnecting Device
*9 - Reversing Device
*10 - Unit Sequence Switch
*11 - "Reserved for future application"
*12 - Overspeed Device
*13 - Synchronous-speed Device
*14 - Underspeed Device
*15 - Speed - or Frequency, Matching Device
*16 - "Reserved for future application"
*17 - Shunting or Discharge Switch
*18 - Accelerating or Decelerating Device
*19 - Starting to Running Transition Contactor
*20 - Electrically Operated Valve
*21 - Distance Relay
*22 - Equalizer Circuit Breaker
*23 - Temperature Control Device
*24 - Over-Excitation Relay
*25 - Synchronizing or Synchronism-Check Device
*26 - Apparatus Thermal Device
*27 - Undervoltage Relay
*28 - Flame Detector
*29 - Isolating Contactor
*30 - Annunciator Relay
*31 - Separate Excitation Device
*32 - Directional Power Relay
*33 - Position Switch
*34 - Master Sequence Device
*35 - Brush-Operating or Slip-Ring Short-Circuiting, Device
*36 - Polarity or Polarizing Voltage Devices
*37 - Undercurrent or Underpower Relay
*38 - Bearing Protective Device
*39 - Mechanical Conduction Monitor
*40 - Field Relay
*41 - Field Circuit Breaker
*42 - Running Circuit Breaker
*43 - Manual Transfer or Selector Device
*44 - Unit Sequence Starting Relay
*45 - Atmospheric Condition Monitor
*46 - Reverse-phase or Phase-Balance Current Relay
*47 - Phase-Sequence Voltage Relay
*48 - Incomplete Sequence Relay
*49 - Machine or Transformer, Thermal Relay
*50 - Instantaneous Overcurrent or Rate of Rise, Relay
*51 - AC Time Overcurrent Relay
*52 - AC Circuit Breaker
*53 - Exciter or DC Generator Relay
*54 - High-Speed DC Circuit Breaker
*55 - Power Factor Relay
*56 - Field Application Relay
*57 - Short-Circuiting or Grounding (Earthing) Device
*58 - Rectification Failure Relay
*59 - Overvoltage Relay
*60 - Voltage or Current Balance Relay
*61 - Machine Split Phase Current Balance
*62 - Time-Delay Stopping or Opening Relay
*63 - Pressure Switch
*64 - Ground (Earth) Detector Relay
*65 - Governor
*66 - Notching or Jogging Device
*67 - AC Directional Overcurrent Relay
*68 - Blocking Relay
*69 - Permissive Control Device
*70 - Rheostat
*71 - Level Switch
*72 - DC Circuit Breaker
*73 - Load-Resistor Contactor
*74 - Alarm Relay
*75 - Position Changing Mechanism
*76 - DC Overcurrent Relay
*77 - Pulse Transmitter
*78 - Phase-Angle Measuring or Out-of-Step Protective Relay
*79 - AC Reclosing Relay
*80 - Flow Switch
*81 - Frequency Relay
*82 - DC Reclosing Relay
*83 - Automatic Selective Control or Transfer Relay
*84 - Operating Mechanism
*85 - Carrier or Pilot-Wire Receiver Relay
*86 - Lockout Relay
*87 - Differential Protective Relay
*88 - Auxiliary Motor or Motor Generator
*89 - Line Switch
*90 - Regulating Device
*91 - Voltage Directional Relay
*92 - Voltage and Power Directional Relay
*93 - Field Changing Contactor
*94 - Tripping or Trip-Free Relay
*95 - Reluctance Torque Synchrocheck
*96 - Autoloading Relay
*97 - "For specific applications where other numbers are not suitable"
*98 - "For specific applications where other numbers are not suitable"
*99 - "For specific applications where other numbers are not suitable"

Note 1: A suffix letter 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 Siemens 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" being a time overcurrent ground relay [ [http://www.geindustrial.com/pm/notes/get8048a.pdf GE Power Management - Relay Selection Guide] ] .