Momentary Sag impact
Momentary Sag impact
(OP)
The transient switchover is usually very fast and unlikely to have an effect on normal electrical plant. However, major problems could be experienced when large DOL induction motors are being started. The acceleration time coould be as short as 1.5s. But it is long enough to cause other motors in the system to reduce the speeds and have to be restarted after the large motor has come to the full speed. Therefore it is important to limit the voltage sag below 5%. Wonder what the impacts would be if the momentary sags (higher than 5%) last only less than 2s, but very frequently, i.e. cruser laods in mining industry. Thank in advance for any comments.




