Nr. |
Description |
1 |
Master element |
2 |
Time-delay starting or closing delay |
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 relay |
26 |
Apparatus thermal device |
27 |
Undervoltage relay |
28 |
Flame detector |
29 |
Isolating contactor or switch |
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 device |
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 |
Abnormal atmospheric condition monitor |
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 |
50 |
Instantaneous overcurrent relay |
51 |
Ac inverse time overcurrent relay |
52 |
Ac circuit breaker |
53 |
Field excitation 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 |
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 |
79 |
Ac reclosing relay |
80 |
Flow switch |
81 |
Frequency relay |
82 |
Dc load-measuring reclosing relay |
83 |
Automatic selective control or transfer relay |
84 |
Operating mechanism |
85 |
Pilot communications, carrier or pilot-wire 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 a 99 |
- used only for specific applications |