Matthias Muehe wrote:
wrote:
hi all..
iam stuck in a gruesome situation..have placed orders for some heavy
duty wood working machinery from US.Most of these involve 3ph,220v,60hz
motors but i need to operate them at 220v,3ph,50hz supply.
can anyone please advice me on what will happen to the production(
efficiency wise.) in this case.
eagerly waiting for ur help..
thnks a ton.
sam.
Hi Sam,
bad news:
You would loose 20% in speed. But most important, most of the 60Hz
motors are not build for running permanently on 50Hz (too little iron),
so they will overheat.
Possible solutions: Frequency converter (this way you will have an
electronic speed adjustment) or change the motors.
regards Matthias
Good News and more good news. The machines will most likely work just
fine on 50Hz. If these are 3 phase machines they are most likely common
squirrel cage induction motors. Three phase induction motors are
frequently powered with variable frequency AC drives at less than base
speed (60 Hz in your case) with no damage or overheating. Yes the speed
will be 16.6% slower, but I doubt you will notice any difference. The
motor will see full mains voltage at 50Hz and will effectively be
operating slightly overvoltage, this also will most likely not be an
issue with only a slight increase in the no load mag current of the
stator windings. Most induction motors are designed to tolerate up to a
20% variance in line voltage. I would be much more concerned if you were
operating in an undervoltage condition, which will definitely fry your
motor slowly. If the equipment includes any control transformers or
starters/contactors then 50Hz may damage the transformers or coil
windings if they are not dual frequency rated. Any electronic controls
are also a concern and probably beyond the scope of discussion on the
newsgroup without specific controller data from the manufacturer.
Scott.