Selected ANSI Device Numbers

  • 1 – Master Element
  • 12 – Overspeed Device
  • 14 – Underspeed Device
  • 27 – Undervoltage Relay
  • 28 – Flame detector
  • 30 – Annunciator Relay
  • 32 – Directional Power Relay or Reverse Power Relay
  • 41 – Field Circuit Breaker
  • 50 – Instantaneous Overcurrent Relay
  • 51 – AC Inverse Time Overcurrent Relay
  • 52 – AC Circuit Breaker
  • 59 – Overvoltage Relay
  • 67 – AC Directional Overcurrent Relay
  • 68 – Blocking Relay
  • 72 – DC Circuit Breaker
  • 76 – DC Overcurrent Relay
  • 78 – Phase-Angle Measuring Relay or "Out-of-Step" Relay
  • 79 – AC Reclosing Relay
  • 81 – Frequency Relay
  • 82 – DC Reclosing Relay
  • 86 – Lockout Relay
  • 87 – Differential Protective Relay
  • 94 – Tripping or Trip-Free Relay