ANSI/IEEE C37.2
From HwB
This table shows name of protection devices used in substations and electrical plants. Number can be combined with letter to describe a function.
Device function
| Function | Description |
|---|---|
| 7 | Sudden Change In Phase/Residual Current Protection |
| 21 | Line Distance |
| 21G | Ground Distance |
| 21P | Phase Distance |
| 24 | Overexcitation (Volts per Hertz) |
| 25 | Synchrocheck |
| 25A | Automatic Synchronizing |
| 26 | Overload |
| 27 | Undervoltage |
| 27N | Ground Fault Undervoltage |
| 27P | Phase Undervoltage |
| 27X | Auxiliary Undervoltage |
| 32 | Power |
| 37 | Undercurrent |
| 40 | Loss Of Field |
| 46 | Phase Balance Current / Current Plausibility Check |
| 46N | Negative Sequence Overcurrent |
| 47 | Phase Sequence Voltage |
| 47N | Negative Sequence Voltage |
| 49 | Thermal |
| 50 | Instantaneous Overcurrent |
| 50BF | Breaker Failure |
| 50DD | Adaptive Fault Detector |
| 50G | Ground Instantaneous Overcurrent |
| 50N | Neutral Instantaneous Overcurrent |
| 50P | Phase Instantaneous Overcurrent |
| 50_2 | Negative Sequence Instantaneous Overcurrent |
| 51 | Time Overcurrent |
| 51G | Ground Time Overcurrent |
| 51N | Neutral Time Overcurrent |
| 51P | Phase Time Overcurrent |
| 51_2 | Negative Sequence Time Overcurrent |
| 51/27C | Voltage Controlled Time Overcurrent |
| 51/27R | Voltage Restrained Time Overcurrent |
| 52 | AC Circuit Breaker |
| 59 | Overvoltage |
| 59N | Neutral Overvoltage |
| 59P | Phase Overvoltage |
| 59X | Auxiliary Overvoltage |
| 60 | Voltage Balance |
| 60FL | Voltage Transformer Supervision |
| 64F | Field Ground |
| 64G | 100% Stator Ground Inputs |
| 67 | Ac Directional Overcurrent |
| 67N | Neutral Directional Overcurrent |
| 67P | Phase Directional Overcurrent |
| 67_2 | Negative Sequence Directional Overcurrent |
| 68 | Power Swing Blocking |
| 74TC | Trip Circuit / Control Circuit Supervision |
| 78 | Out-of-Step / Pole Slip |
| 79 | Automatic Recloser |
| 81 | Frequency |
| 87 | Differential Protective |
| 87B | Bus Differential Protective |
| 87L | Segregated Line Current Differential |
| 87T | Transformer Differential Protective |
| 87N | Low Impedance Differential Protection |
| 87V | Voltage Differential Protection |
| 90 | Transformer Control |
Standards
- IEEE C37.2-1991 (ANSI)