Re: Switches Anyone?

[Jim <alarminex@xxxxxxx>]

On Wednesday, April 17, 2013 5:30:48 PM UTC-4, Bob La Londe wrote:

What is a variable frequency drive? I know what is sounds like it is but > =
> Are you just talking about variable 50/60 cycle or something different? >=
 And why would you need that on a spindle drive ( I presume for your CNC > =
machine)=20


Well, that one will be set to run up as high as 665 hz to drive the spindle=
 motor upto about 40,000 RPM at the high end. My big mill has one that is s=
et for 3 hz to 120 hz to drive the spindle from 96 RPM to about 3600 RPM. Y=
ou can vary the speed of a three phase motor by varying the frequency. Upto=
 24000 RPM motors that run at upto 400 hz AC are fairly common.

Ahhh, I'm not knowledgeable at all about three phase. I didn't know frequen=
cy was involved with the speed.=20