Electric motor advice needed

[TDKPE]

I could try setting it up  to run 115 and see if that helps, but I don't know why reversing the polarity would make a certain voltage unsuable, 230 in this case.

It shouldn't.  There shouldn't be any difference.  

But you still shouldn't be trying to run that motor on the wrong voltage.  

This is what you have right now, though I may have the start (B-winding) leads reversed.  The #2 post isn't used on this motor, but would be used if it had integral overload protection.  The #3 post isn't connected inside the motor, and is just a junction point.

Arrows are just for reference, as 1/120s later, current flows in the opposite direction.

   

[TDKPE]

Same motor reconfigured for 120V operation.  Notice that all three windings are wired in parallel.  In the 240V configuration, the B winding is in parallel with just one A (run) winding, and the other A winding is in series with that pair.  

Neither the #2 nor the #3 post are used.

   

[DCottrell]

OK I'll try it set up to run 115

Thanks for all your assistance.

I'll let you know how it turns out

[DCottrell]

I set it up to run at 115v in CW way , which is how I want to use it.  This is according to the plate on the motor

Plugged directly into the wall (GFI circuit).  Switch off

Flipped switch, tripped breaker. No joy in Mudville.

I then set it up for 115v in CCW.  Works great!.    So maybe this was misbranded as reversible?  It works at both voltages in CCW direction, but does not like when I reverse the polarity, regardless of the voltage.



Unless y'all know how to put the arbor on the other end, I may put this plan on the back burner and reinstall the 1/2 hp motor, though I already bored out the pulley to fit this motor. Now I need to spend time making a bushing.  Or trying to reconfigure the bandsaw setup  to have an outboard table that holds this motor facing the right way.

I think machinists call it "yak shaving",  I call it "working backwards", when the more you do, the farther away from your original goal you get.

Time for a beer, though its only 3:30 here in Maryland

[TDKPE]

Is this the stud terminal numbering?  Presently wired for 240V, and reversed (from standard) rotation?

   

[TDKPE]

Check for continuity between the two start winding leads, red and black, and the frame.  Unplugged, of course.  It's likely one of them is shorted to ground, possibly inside the capacitor cover.  

When connected for 240V operation, there is a 'neutral' point where the two run (A) windings are at zero volts, which is on stud #3.  If that start lead is touching the case, it won't matter, though there will be some small current as it starts due to the unbalance of the extra winding (B).

Reversing it would put that shorted (ground fault, actually) lead on a hot conductor.

Same with 120V, though the faulted lead would be on the neutral in one direction, and on the hot when reversed.

Worth a quick peak, as you only need a continuity light or DMM or AMM or something.

[DCottrell]

Yes you got the  terminal numbers right

Very interested in the short idea.  There is continuity with the red and the ground.  There is a dime-sized dent in the capacitor housing.  When I get a chance later, I'll see if I can pop that cover off and see if there is something shorting to ground there.  I like the idea that the red is neutral in one direction and hot when reversed, and if it grounds out, that might be what is happening.

Back in a bit

[DCottrell]

WE HAVE A WINNER!!

I took off the dented capacitor cover, noticed the plastic housing was cracked, it must have taken quite a blow.  Red leads to the cap.

With no cap cover, wired low voltage CW, runs great! 

Nice catch on the short to ground.  It was indeed the red lead, which runs to the cap which was shorting out on the dented housing

Thanks to all for your help and especially TDKPE for the correct steerage.

Now, should I wire it to run at 115 or 230?   If low voltage will the bandsaw bog down?  

Thanks !!

[Roly]

WE HAVE A WINNER!!

I took off the dented capacitor cover, noticed the plastic housing was cracked, it must have taken quite a blow.  Red leads to the cap.

With no cap cover, wired low voltage CW, runs great! 

Nice catch on the short to ground.  It was indeed the red lead, which runs to the cap which was shorting out on the dented housing

Thanks to all for your help and especially TDKPE for the correct steerage.

Now, should I wire it to run at 115 or 230?   If low voltage will the bandsaw bog down?  

Thanks !!

They designed it to be able to rewire it for correct voltage for a reason. Depends on the load on the bandsaw if it bogs down,  I think by changing out the 1/2 hp for a 3/4 hp  motor but operating at half voltage  you will have even less power than the 1/2 hp .   Watch for overheating.    Roly

[TDKPE]

Now, should I wire it to run at 115 or 230?   If low voltage will the bandsaw bog down?  

If your shop voltage is 120V only, use the 115V connection scheme.  

Connecting for 240V but running on 120V will result in the entire torque curve being depressed to 1/4 of what it would be at 240V.  It will be weak and wimpy beyond belief.  For a polisher or similar light duty, you might never notice it being weak, but on a band saw it may not even be able to start due to both inertia, and the frictional losses in the drive (belt), bearings, and friction in the rubber wheel/tire interface, and so on.  As a result, the output power will also be tiny, since the torque curve is tiny.  Synchronous speed (no-load speed, basically) will still be the same, but torque will be pathetic, and being that power is torque times speed, power will be pathetic.

It would be a severe undervolt condition.  Use the connection that matches the supplied voltage and the torque curve will be where it should be, as will the output power.

Glad it's working now.