| Protection | IEC symbol (IEC60617) | ANSI (IEEE C37.2) | Operate time |
|---|---|---|---|
| Under-frequency | f<, f<< | 81U | < 50 ms |
| The alarm response is based on the highest fundamental frequency (based on phase voltage), from the source. This ensures that the alarm only activates when all of the phase frequencies are below the set point. |
Source 2 > Frequency protections > Under-frequency > S2 f< [1 to
5]
| Parameter | Text | Range | S2 f< 1 | S2 f< 2 | S2 f< 3 | S2 f< 4 | S2 f< 5 |
|---|---|---|---|---|---|---|---|
| 1381, 1391, 1401, 1411 or 1931 | Set point | 80 to 100 % | 97 % | 95 % | 97 % | 95 % | 95 % |
| 1382, 1392, 1402, 1412 or 1932 | Timer | 0.04 to 99.99 s | 10 s | 5 s | 10 s | 5 s | 5600 s* |
| 1385, 1395, 1405, 1415 or 1935 | Enable |
OFF ON |
OFF | OFF | OFF | OFF | OFF |
| 1386, 1396, 1406, 1416 or 1936 | Fail class | Fail classes | Warning | Warning | Warning | Warning | Warning |
Note: * The range for this alarm is 1500 to 6000 s.