Re - What motor should I use
Posted by
bwrfromuk
on 2002-02-05 15:44:18 UTC
The reason that mains a.c. motors are limited to 3600 RPM is that you
can't have less than a two pole motor, so with a 60Hz supply the
limit is 3600 RPM.
From a safety aspect I can't see that a 3 phase motor running at
14,600 RPM, through a variable frequency drive, is any more dangerous
than say a 32,000 RPM hand held router. In fact as you don't have
all the commutator segments in there I would suggest it is far more
safe.
I agree that if the output is going to be geared in any way through
either belts or gears it is very important to check that there aren't
any lumps of cast iron spinning at excessive RPM, but in any high
speed machine you need to be very aware of what's in the drive train
and how it's balanced.
can't have less than a two pole motor, so with a 60Hz supply the
limit is 3600 RPM.
From a safety aspect I can't see that a 3 phase motor running at
14,600 RPM, through a variable frequency drive, is any more dangerous
than say a 32,000 RPM hand held router. In fact as you don't have
all the commutator segments in there I would suggest it is far more
safe.
I agree that if the output is going to be geared in any way through
either belts or gears it is very important to check that there aren't
any lumps of cast iron spinning at excessive RPM, but in any high
speed machine you need to be very aware of what's in the drive train
and how it's balanced.