Kirk Wallace <kwall...@...> writes:
> Thanks Tom, that fixed it. > snip... > > I haven't checked this yet, but I suspect that the PWM voltage to the > motor is still 220 Volts. The motor has a 110 Volt rating, so this may > be an issue. > > I have no idea how well the bearings would hold up, but it may be easy > to upgrade these if necessary. > Hi Kirk, Glad hear you got it spinning without vfd errors. Downstream from the 220V rectifier, the DC bus voltage on these units is usually around 340vdc - so that is the peak-to-peak switching voltage to the motor. If your motor is acting kind of nervous or jerky and fussy, then lowering the max motor voltage in the vfd will mellow it. My motor/vfd on Youtube: http://www.youtube.com/watch?v=q_m_ouL7zRI Motor parameters: nameplate=3 phase induction motor 195V / 5.6A / 820W / 236 Hz / 16,000 rpm VFD parameters: motor power=.95KW motor volts=190V motor freq=300Hz motor current=5.09A motor nom. speed=16,520rpm freq. range=0-1000Hz (most Danfoss vfds can go this high!) min freq=0Hz max freq=300Hz ramp up time=5.s ramp down time=5.s current limit=7.8A Yes, keep an eye on those bearings and put a cooling fan on the motor. I tried holding the spindle with a rag in my hand at max speed, and I was able to drag it down so that it was pulling around 7 amps. It did not feel very torquey, but I could set the vfd to constant torque to compensate for this. The motor heated up, but not too hot to touch. Motor heat may have to do with vfd parameters, and possibly even the base switching frequency of the vfd, which should be set as high as possible ( I think it can be set as high as 50KHz on the Danfoss.) It might be interesting to try the inductors that Jon mentioned to see if they affect motor heating. Fun! Tom ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
