In the world of electrical power systems, the ANSI/IEEE device numbering system promotes clarity and standardization.
In electrical power systems, clear communication is critical for safety and reliability. The American National Standards Institute (ANSI) and the Institute of Electrical and Electronics Engineers (IEEE) device numbering system provides a standardized language for identifying protective relays, controls, and other devices across the industry. This universal code allows engineers to quickly interpret relay functions on single-line diagrams, troubleshoot protection schemes, and coordinate settings between utilities.
For protection engineers, understanding this numbering system is fundamental to designing and maintaining effective power system protection. Whether specifying new equipment or analyzing existing installations, proficiency with ANSI/IEEE device numbers is an essential skill in the field of power system protection and control.
A Common Language for Power System Protection
In electrical power systems, clear communication is critical for safety and reliability. The ANSI/IEEE device numbering system provides a standardized language for identifying protective relays, controls, and other devices across the industry. This universal code allows engineers to quickly interpret relay functions on single-line diagrams, troubleshoot protection schemes, and coordinate settings between utilities.
Simplifying Complex Systems
The ANSI/IEEE numbering system offers several practical benefits:
Common reference: It allows engineers and technicians from different backgrounds to communicate effectively about protection schemes using a shared terminology.
Simplified documentation: The numerical codes simplify the representation of protective functions on single-line diagrams and relay settings sheets.
Clarity in multi-function devices: With modern microprocessor-based relays performing multiple functions, the numbering system helps clearly identify which specific protective elements are enabled.
Historical continuity: While technology has evolved, the numbering system maintains a link to traditional electromechanical relay practices, aiding in system upgrades and retrofits.
Design and troubleshooting: The standardized numbers facilitate quicker interpretation of protection schemes during both system design and fault analysis.
Essential Knowledge for Protection Engineers
For protection engineers, a thorough understanding of this numbering system is essential for effective communication, proper relay configuration, and coordinated protection design. However, it’s important to note that the ANSI/IEEE system is just one part of the broader knowledge required in power system protection, including system analysis, relay theory, and practical application experience.
Conclusion
Whether specifying new equipment or analyzing existing installations, proficiency with ANSI device numbers is an essential skill in the field of power system protection and control. It forms a fundamental part of the protection engineer’s toolkit, enabling clear communication and efficient system design across the global power industry.
| Device Number | Description |
|---|---|
| 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 | Rate of Change Relay |
| 8 | Control Power Disconnecting Device |
| 9 | Reversing Device |
| 10 | Unit Sequence Switch |
| 11 | Multifunction Device |
| 12 | Overspeed Device |
| 13 | Synchronous-speed Device |
| 14 | Underspeed Device |
| 15 | Speed – or Frequency, Matching Device |
| 16 | Data Communications Device |
| 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 | Volts Per Hertz 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 |
| 51 | AC Time Overcurrent Relay |
| 52 | AC Circuit Breaker |
| 53 | Exciter or DC Generator Relay |
| 54 | Turning Gear Engaging Device |
| 55 | Power Factor Relay |
| 56 | Field Application Relay |
| 57 | Short-Circuiting or Grounding Device |
| 58 | Rectification Failure Relay |
| 59 | Overvoltage Relay |
| 60 | Voltage or Current Balance Relay |
| 61 | Density Switch or Sensor |
| 62 | Time-Delay Stopping or Opening Relay |
| 63 | Pressure Switch |
| 64 | Ground Detector Relay |
| 65 | Governor |
| 66 | Notching or Jogging Device |
| 67 | AC Directional Overcurrent Relay |
| 68 | Blocking or “Out of Step” 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 | Telemetering Device |
| 78 | Phase-Angle Measuring or Out-of-Step Protection Relay |
| 79 | 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 | For future use |
| 96 | For future use |
| 97 | For future use |
| 98 | For future use |
| 99 | For future use |