This particular problem has been solved. The PLC program has been modified to include an OFF2 command which is basically giving a 100 ms time delay before disconnecting the motors from the drive. Everyting was OK, except for this additional time delay which reduced or eliminated the...
Thank you for all the excellent advice. You all deserve a star.
Apparently, after coming to the plant for several nights to check on the situation, I thought I have narrowed down the cause of this “mysterious” problem. After shutting down the furnace cooling fans, the frequency drive indicator...
Hi jraef, thank you for the reply, I appreciate it.
Do you think increasing the ACCEL time would help? It is at 11 sec. right now. I will try to give some starting boost, as you recommended.
Thanks,
sawal
We have a Siemens Midimaster Vector 1500/4 freq. drive, 15kw, 575 vac, 3 ph. that drives (6) sets of (4) blower motors for a Tamglass furnace. the drive starts the first set of motors, and after reaching the set speed the power is transferred to the 575 vac mains. Then the drive starts the next...
