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