I have a gearmotor that I have bought for a new project. 3 phase.
I have a variable frequency drive for it. 120 VAC single input to 240 three
phase out.
Then I jack that up to 480 with a transformer.
10 Hz = 600 cycles per minute
Divide by 2 as there are 4 poles and I think that means 300 electrical cycles
per rotation (this is probably where I am going wrong) = 300
Divide by 15 due to the gearbox 15:1 reduction and you get 20 RPM. But it
actually spins at 26 RPM.
I was hand counting revs.
We did 5 Hz and got 13 RPM so I think the factor is more like 1.538 cycles per
rotation.
1.538 cycles per rev?
Where am I going wrong?
Roughly 270 degrees per cycle?
Maybe that is it but I don’t know why.
10 Hz = 600 cycles per minute.
600*270=162000 degrees per minute.
162000/360=450 rpm
450/15=30 rpm
Nope.
So working backwards:
26*15=390 motor RPM
390*360=140400 degrees per minute.
140400/600=234 degrees per cycle
I don’t recognize that as any kind of magic number...
--
AF mailing list
[email protected]
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
