Re: sync motor wiring question

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

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

In a message dated 3/25/02 2:15:11 AM Eastern Standard Time, tesla-at-pupman-dot-com
writes:


>
> Regarding your motor, I'm no expert but I would fathom a gusess from your
> data you
> have something like this
>
>
>     Blk------3                       Yel------ 3
>                   3    210                             3   91
>     Wht-----3--------------------------3
>                   3   210                              3   180
>     Red-----3                      Blu------- 3



Hi Dave,

Your schematic above is what I was trying to figure out, so that
was a big help.  I had a part of it correct, but not all.  I also have 
a 2 speed H-sync motor with 6 wires, and that one I did figure out 
OK in the past.  I also found out that it required the exact
capacitance the label called for.... unlike a typical induction/sync 
motor which can use a range of C values.  more below..... I did some
tests.....

>
> If you have a variac, I recommend experimenting a little to decipher the
> correct
> hookup.  That how I figured mine out.
>
> It looks like the Blk-Wht-Red winding is probably your 120V power winding
> and the
> Yel-Blu winding is the phase shifted one that gives the rotor a push.  Here
> are
> some options I would try:
>
> (1) Line across Blk and Wht.   Red Open.   Cap across Yel and Blu.
> (2) Line across Blk-Red (shorted) and Wht.  Cap across Yel and Blu
>
> If those don't work then you will probably have hook the cap from the line to
> either Yel or Blu.   It looks like hooking up either Yel or Blu to Wht is not
> a
> good idea since you would be shorting a winding out,  assuming my schematic
> is
> correct.   Another possiblity is connecting Blu up to the line with the cap
> across
> Yel and Blu.   Actually there are lots of possiblities aren't there which
> is why
> you wrote your post the the list.   Sorry I cant be more help.



I tried all your above suggestions, but none worked, but a similar one
worked but the motor spun weakly:

   Blk-Red shorted  -  line
   yellow    -  line
   yellow and blue to cap
   motor spun CCW weakly

Then I tried:

   Same as above, but:

   cap to red-black(shorted) -  line
   cap to blue

This spun CW (I think) and was weak also.

Next I tried:

   white to line
   blue to line
   Cap to blue and yellow
   red and black no connections, no short
this ran CCW strongly  

Then I tried:
     white to line
     yellow to line
     cap to blue and yellow
     red and black no connections, no short
This also ran CCW(I think) and strongly.

In no case was the motor really very strong.
I'm using a 3uF cap instead of a 3.5uF specified.
not sure if it makes much difference, it may.
I wonder what the black and red wires are for
(assuming I hooked it up correctly now)?
This motor is running at 900 rpm sync now.  I didn't
yet check to see if it runs at different speeds with
a different hook up.  I have still another motor which
lists the speeds and HP, and it seems the HP varies
with the speed, lower speed = lower HP.  I'll try some
more tests.


>
> Regarding using a hysterisis motor for your SRSG, my gap works very well
> with this
> kind of motor.   The big hassle is getting the phase adjusted.   I worked
> around
> this problem by flicking the AC off momentarily with a switch while
> monitoring my
> NST output on the scope.   



Yes, I had seen your previous posting about flipping the switch,
and I know an H-motor can work, but it's not all that convenient
generally.  I said what I said before about the H-motor not being
ideal to let folks know that I was aware of their shortcomings,
so they wouldn't feel compelled to alert me about them   :)

Thanks,
John