Re: Motor start/run Circuits References

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 12/28/00 9:42:48 AM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:

> Team
>  
>  Lots of net searching and textbook reviews draws a blank on how motor run
>  and start caps are connected  and used. Can readers suggest a net ref
>  showing how extra windings are used wirth these caps. (The prospective
>  purchase for a SRSG motor has many windings and of course no data)
>  
>  Rgds to all
>  Ted L

Ted,

For cap start, they sometimes use a separate relay that disconnects
the cap after starting.  Other times, they use an internal centrifugal
switch.  For cap run, I often measure the two windings with an
ohmmeter and assume that the higher resistance winding is
the one fed by the cap.  the cap is connected between one ac lead
and the run winding.  The other end of run winding is connected to
the other ac lead.  The main winding is connected directly across
the ac line input.  Some motors are multispeed and have more
wires.  Some have a ground wire too.  Some can run on either
120 or 240 volts, and the wires should be put in series or
parallel as needed.  There may be a color code, I forget it though.

Avoid hysteresis sync motors for sync gaps, because they can
lock in any random phase position each time they start.

John Freau