51. AC Ovrcurrent Rel. 52. AC CB 53. Ex. or DC Gen. Relay
54. High speed DC CB 55. Pfactor Relay 56. Field App. Relay
57. Shor-cicuiting Grounding Device 58. Power Rectifier Misfire Relay 59. Overvoltage Relay 60. Vol. Balance Relay
61.Current Balance Relay 62. Time delay stopping or opening relay 63. Liquid or Gas Pressure, level or flow relay
64. Ground Protection Relay 65. Governor 66. Notching or jogging device 67. AC Directional Overcurrent Relay 68. Blocking Relay 69. Permissive control device70.Electrically operated rheostat 71. FA 72. DC CB 73. Load resistor contactor 74. Alarm relay 75. Position changing mechanism
76. DC overcurrent relay 77. Pulse transmitter 78. Phase angle meas.or Out-of-step Prot. rel. 79. AC Reclosing relay
80. FA 81. Frequency Relay 82. DC Reclosing realy 83. Automatic Selective Control or transfer relay 84. Operating mechanism 85. Carrier or Pilot wire Receive relay 86. Lock out relay 87. Differencial relay 88. Auxiliary motor or motor generator 89. Line switch 90. Regulating device 91. Voltage directional relay 92.Voltage or power directional relay 93. Field changing contactor 94. Tripping or trip-free relay 95 to 99 specific application other than included above.
There is also provision for the prefix RE for remote and suffix to device number for specific use.