Re: [CAD_CAM_EDM_DRO] Re: VFD and inverter duty 3phase motors

In a message dated 7/31/2004 12:14:07 AM Eastern Daylight Time,
DougR@... writes:

Hmmmm......what you guys are saying is contrary to the info Baldor
is giving me. They tell me it's ok to run their newer non-inverter
duty 60 hz rated motors up to 5000 rpm.

With an 1800 rpm 60hz motor that would involve programming the max
hertz output of the VFD to 166 hz.



I hate to tell you this but it was a Baldor motor that I saw come apart.
Now, the guy was trying to run it at 12,000 rpm. Also, I was under the
impression you were talking about a motor that ran at 3450 rpm at 60Hz and then
running the frequency up to 400Hz. Did Baldor tell you that their 1800 rpm motor
was the one that would operate at 5000 rpm? I have run quite a few 60Hz
motors at 70Hz, ones that were rated at 3450rpm or there abouts and had no
problem that translates to about 4025 rpm at 70 Hz. Also keep in mind that if the
motor is wound for slower speeds it is probably not going to have the torque
at higher frequencies.

Randy Abernathy
4626 Old Stilesboro Road NW
Acworth, GA 30101-4066
Phone / Fax: 770-974-5295
Cell: 678-772-4113
E-mail: Cnc002@...

I furnish technical support, repair, and other related services for your
industrial woodworking machinery. My background as Senior Service Engineer for
the SCMI Group for nearly fifteen years with factory training, combines with
my extensive background in electronics, mechanics, pneumatics, electrical and
CNC machinery to offer you needed support for your machinery.


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