Re: sync motor wiring question

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

Original poster: "Dave Lewis by way of Terry Fritz <twftesla-at-qwest-dot-net>" <hvdave-at-earthlink-dot-net>

Hi John,

Good to hear you got your motor spinning.   I'm also wondering what the
Red and Blk wires are for too - I would bet good money they are supposed
to be used.   But, if the motor is strong enough and not getting too hot
then who am I to argue with success.   On the other hand, trying to
figure it out is a fun little puzzle too.

A couple more you might try if you haven't already

 (A) Wht to line
     Yel, Blk, & Red shorted together to line
     Cap to Blu and Yel

     or

 (B) Wht to line
     Blu, Blk, & Red shorted together to line
     Cap to Blu and Yel

I'm thinking the Red and Blk windings may be part of the main poles. 
(B) might be the way just since the Yel-Wht winding is about 1/2 the
resistance of the others making it stand out as the phase shifted
winding.   You have an 8 pole motor so there's got to be a whole bunch
of windings.

Did you notice any differences in how long it takes to spin up?  I would
say the correct connection would spin up in the least amount of time.

I don't think the 3.0uF vs 3.5uF cap will matter at all.  Those caps are
probably 10% tollerance.

Good luck,
Dave Lewis




Anyways, good luck

Tesla list wrote:
> 
> 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