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Ignoramus9935 Ignoramus9935 is offline
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Default 3 pha motor tips needed

How many leads still have numbers? What are the numbers that you see?

I had this problem with my Bridgeport. Only some wires had numbers and
it was wired for 440v at the printing shop where it came from.

i

On 2008-07-04, Wes wrote:
Uncle's 5hp single phase motor for his A.O. Dobbs table saw (big sucker) croaked on him so
he went down to the scrap yard and bought a 5 hp 3 phase motor.

I looked at the partially marked wires and the data plate and did my best to figure out it
was low voltage wired. Tip is that 3 wires together. From what I can see, your normal 3
phase motor has once set of windings internally connected to form a wye. From there you
either add in series another winding to each leg of the wye for HV or you build another
wye out of the three other windings and parallel them.

Ohming the windings did not find any shorts to ground. Uncle meter sucks so I can not
tell if a winding is shorted to itself but not to frame.

My first thought is maybe each wye isn't properly oriented to the other one.

My second thought is disconnect all the wires, find the three that are internally
connected and attach power to just those to test the motor. I would think it would make
it a 2 1/2 hp motor that would get him by for a while.

My third thought is to play with the other 6 wires and make another wye trying
combinations to see if those can run it.

The forth thought is if I can get set 1 and set 2 to run the motor, try the 3 arraignments
of paralleling them to get the 5 hp.

Are my thoughts right? Thanks,


Wes


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