Capacitor-run induction motor windings

Started by September 5, 2017
Hello,

I'm hoping to convert old household induction motors to brushless motors basically
by replacing the rotor with magnets. However I'm having difficulty understanding the
stator winding patterns. I need to isolate the phases obviously. Any suggestions?
Even if they are two phase instead of three phase, that is useful too.

Thanks,

Michael
On Tuesday, September 5, 2017 at 4:03:07 PM UTC-7, mrda...@gmail.com wrote:

> I'm hoping to convert old household induction motors to brushless motors basically
by replacing the rotor with magnets. Induction motors ARE brushless, of course. How would this conversion produce any benefit?
On 2017-09-05, mrdarrett@gmail.com <mrdarrett@gmail.com> wrote:
> Hello, > > I'm hoping to convert old household induction motors to brushless > motors basically by replacing the rotor with magnets. However I'm > having difficulty understanding the stator winding patterns. I need to > isolate the phases obviously. Any suggestions? Even if they are two > phase instead of three phase, that is useful too.
Don't overthink it. When you have the motor disassembled (a neccessary step if you intend to replace the rotor) place a compass inside the stator and apply a small DC current to each winding and observe the magnetisation pattern. -- This email has not been checked by half-arsed antivirus software
On Wednesday, September 6, 2017 at 3:01:27 PM UTC-7, Jasen Betts wrote:
> On 2017-09-05, mrdarrett@gmail.com <mrdarrett@gmail.com> wrote: > > Hello, > > > > I'm hoping to convert old household induction motors to brushless > > motors basically by replacing the rotor with magnets. However I'm > > having difficulty understanding the stator winding patterns. I need to > > isolate the phases obviously. Any suggestions? Even if they are two > > phase instead of three phase, that is useful too. > > Don't overthink it. > > When you have the motor disassembled (a neccessary step if you intend > to replace the rotor) place a compass inside the stator and apply a > small DC current to each winding and observe the magnetisation pattern. >
Good idea! Thanks! I'll try that once I disassemble the old garage door motor (capacitor-start, I think). Michael
On 9/6/2017 1:28 PM, whit3rd wrote:
> On Tuesday, September 5, 2017 at 4:03:07 PM UTC-7, mrda...@gmail.com wrote: > >> I'm hoping to convert old household induction motors to brushless motors
basically by replacing the rotor with magnets.
> > Induction motors ARE brushless, of course. How would this conversion produce any
benefit?
>
Variable speed?
On Tue, 5 Sep 2017 16:03:03 -0700 (PDT), mrdarrett@gmail.com wrote:

>Hello, > >I'm hoping to convert old household induction motors to brushless motors basically
by replacing the rotor with magnets. However I'm having difficulty understanding the stator winding patterns. I need to isolate the phases obviously. Any suggestions? Even if they are two phase instead of three phase, that is useful too.
> >Thanks, > >Michael
A capacitor run motor will probably have two identical windings, they are in essence two phase motors with the capacitor providing the phase shift. A cap start motor, one with no run cap, will only have one winding energized during normal running. It will not have two identical windings. Single phase induction motors with a switching device and no cap will also not have two identical windings. So make sure you are starting with the kind of motor you want. Eric