# ANSI Protection Codes **URL:** \ **Category:** Electrical\ **Tags:** basic\ **Created:** [August 19, 2024, 11:51pm UTC](https://forumautomation.com/t/ansi-protection-codes/12452 "2024-08-19T23:51:35Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![Rabert](https://forumautomation.com/user_avatar/forumautomation.com/rabert/32/6784_2.png) [@Rabert](https://forumautomation.com/u/Rabert)\ **Post date:** [August 19, 2024, 11:51pm UTC](https://forumautomation.com/t/ansi-protection-codes/12452/1 "2024-08-19T23:51:35Z")
**[ANSI (American National Standards Institute)](https://forumelectrical.com/ansi-standards/)** protection codes are a system of categories that specify the amount of protection given by safety equipment and devices, particularly personal protective equipment (PPE). ![image](https://cdn.forumautomation.com/original/2X/f/fc4fcf4d34ecbb13a24411194b97be634cc45730.jpeg) These codes ensure that the equipment fulfils particular safety standards, which protect against hazards such as impact, chemical exposure, & electrical threats. The codes are widely utilised in many industries to ensure worker safety & compliance with regulatory standards. - **1 – Master Element** - **2 – Time delay Starting or Closing Relay** - **3 – Checking or Interlocking Relay** - **4 – Master Contactor** - **5 – Stopping** - **6 – Starting Circuit Breaker** - **7 – Rate of Change Relay** - **8 – Control Power Disconnecting Device** - **9 – Reversing Device** - **10 – Unit Sequence Switch** - **11 – Multi-function 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 Contractor** - **20 – Electrically Operated Valve** - **21 – Distance Relay** - **22 – Equalizer Circuit Breaker** - **23 – Temperature Control Device** - **24 – Volts Per Hertz Relay** - **25 – Synchronizing or Synchronize-Check Device** - **26 – Apparatus Thermal Device** - **27 – Undervoltage Relay** - **27s- DC under voltage Relay** - **28 – Flame detector** - **29 – Isolating Contactor or Switch** - **30 – Annunciator Relay** - **31 – Separate Excitation** - **32 – Directional Power Relay or Reverse 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 Condition Monitor** - **40 – Field (over/under excitation) Relay** - **41 – Field Circuit Breaker** - **42 – Running Circuit Breaker** - **43 – Manual Transfer or Selector Device** - **44 – Unit Sequence Starting Relay** - **45 –DC over voltage Relay** - **46 – Reverse-phase or Phase-Balance Current Relay** - **47 – Phase-Sequence or Phase-Balance Voltage Relay** - **48 – Incomplete Sequence Relay** - **49 – Machine or Transformer, Thermal Relay-OLR** - **50 – Instantaneous Overcurrent Relay** - **50G - Instantaneous Earth Over Current Relay (Neutral CT Method)** - **50N - Instantaneous Earth Over Current Relay (Residual Method)** - **50BF - Breaker failure** - **51 – AC Inverse Time Overcurrent Relay** - **51G- AC Inverse Time Earth Overcurrent Relay (Neutral CT Method)** - **51N- AC Inverse Time Earth Overcurrent Relay (Residual Method)** - **52 – AC Circuit Breaker** - **52a- AC Circuit Breaker (CB) Position (Contact Open when Breaker Open)** - **52b- AC Circuit Breaker (CB) Position (Contact Closed when Breaker Open)** - **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** - **64R - Restricted earth fault** - **64S - Stator earth fault** - **65 – Governor** - **66 – Notching or Jogging Device** - **67 – AC Directional Overcurrent Relay** - **68 – Blocking Relay** - **69 – Permissive Control Device** - **70 – Rheostat** - **71 – Liquid 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 Relay or “Out-of-Step” Relay** - **79 – AC Reclosing Relay (Auto Reclosing)** - **80 – Flow Switch** - **81 – Frequency Relay** - **82 – DC Reclosing Relay** - **83 – Automatic Selective Control or Transfer Relay** - **84 – Operating Mechanism** - **85 – Communications, Carrier or Pilot-Wire Relay** - **86 – Lockout Relay/Master Trip** - **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( Trip Circuit Supervision Relay)** - **95 – For specific applications as other numbers are not suitable** - **96 – Busbar Trip Lockout 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** - **150 – Earth Fault Indicator** - **AFD – Arc Flash Detector** - **CLK – Clock or Timing Source** - **DDR – Dynamic Disturbance Recorder** - **DFR – Digital Fault Recorder** - **DME – Disturbance Monitor Equipment** - **ENV – Environmental Data** - **HIZ – High Impedance**