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Sounds to me like it isn't a star-delta motor. From your description, I'd say you've got a 2 speed consequent pole motor and it's hooked up wrong. Can you post a photo of the nameplate? What are the speeds and HP ratings?
That's what I'm thinking too, but also keep in mind that to those unfamiliar with them, it may look like a "wye delta" starter.

A real common problem with two speed motors is that the average electrician, even an industrial electrician, doesn't encounter them very often. So when one comes along and the installer has never seen one, he may not understand that there are different types. So he may have read the rules on protecting "2 speed motors" that say that each set of windings must have its own OCPD, not understanding that this only applies to 2 speed 2 winding motors, not to 2S1W. That would explain the separate disconnects. So if it is a 2S1W consequent pole motor, and someone turned off a disconnect thinking they were only disabling one speed, they were in fact likely causing a severe overload on the remaining circuit. But I'd have to see exactly WHICH of the conductors they were opening to be sure. The other issue is that depending on the nature of the machine, it may be necessary to always start it in low speed and change to high, but if they disabled the low speed, it put too much thermal stress on the motor trying to accelerate it in high all the time.

So yes, a picture of the motor nameplate and maybe a napkin schematic of the power connections would be helpful.
 

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Yeah, sounds like a Consequent Pole variable torque connection, probably looks something like this.



You may have the order backward in terms of which ones come on for which speed.
 
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