hey, what's wrong with Rube Goldberg?

but seriously, what I said was that I have a 5 inch muffin fan
attached to the back of the TEFC motor on my lathe, that way when it
is running really slow, I turn on the muffin fan and can leave the
motor running for hours at a time. The problem is not the heat
per-se, the problem is that at low RPM the fan doesn't move any air,
so there is inadequate cooling - I suppose pointing a room fan at the
motor would help too, but that seems pretty unaesthetic


On Fri, 02 Dec 2005 05:07:41 GMT, Bill Rubenstein
wrote:

I don't think anybody has mentioned this in the thread...

Another thing to keep in mind. If you are using a 3 phase motor not
specifically designed for use with a VFD, slow speed running may cause
it to overheat. VFD rated motors are built with higher temperature
insulation on the windings because when the motor runs slowly, the fan
runs slowly.

I think that Bill N has suggested running a plain old fan pointed at the
motor in a prior thread but that seems a little Rube Goldberg to me.

Bill (R)