Can a three phase motor wired in wye be rewired for delta?

Thanks to everyone that has helped me out on this.

The surface grinder has three motor systems, the spindle motor wired in 208/220, the hydraulic pump motor wired 220, and the lube pump motor. I finally found the motor tag for the lube pump which after a bunch of cleaning showed it to be wired for 208.

Now that I know there are no 120 volt systems in the machine , and after all the information you all provided, I feel a lot more comfortable with the RPC route.
 
Hi. This motor can easily be changed from 415-440 Wye (or Y) connection to Delta 208-230V. Just look at google photos for determining which pairs of wires need to be joined. Hint: in Y mode, there are 3 single wires to be connected to the supply, with the other 3 connected each other only.
Another hint: very often the terminal arrangements are pasted on the INSIDE of the terminal box lid - and you are worrying much more than necessary :)
I'm a bit puzzled by the "9 wire" comment. There are three sets of coils with two ends each in the motor - that makes 6. Or did you count the 3 wires for the power GOING IN?
Also, your pump motor may only have 3 wires in the terminal box. If so, the other 3 are joined to each other internally, which means you may need to open up the motor and find that soldered or welded joint, to bring those 3 wires out into the junction box too. Sometimes that is very easy (in fact I have seen that joint made and hidden INSIDE the junction box - which makes it very easy.
On the other hand, if there are already 3 pairs of wires terminated in the terminal box, and the motor labelled 400/414/440V, then it is already in delta mode - and that is the lowest voltage it will provide the maximum power. SO you might be stuck. However, it is still worth trying that motor on 220V 3-phase, because you may not NEED the rated motor power to pump what you need. Never give up too easily :)
I've converted loads of motors that others had given up on.... If you need more detailed help, take a nice sharp photo of the terminal box with the lid off both motors.
If finding the "star point" joint inside the motor is required, don't despair: take that motor apart and show us a few photos of the stator end with all the insulating sleeves. Chances are high that I can find it for you in a photo.
 
Thanks Joe.

With leads 4, 5, and 6 tied together I believe I'm looking at a 220 volt wired motor in wye configuration.

If it were high voltage I believe that leads 4 and 7, 5 and 8, and 6 and 9 would be tied together.

This counts the line wires, 3 line and 6 leads from the motor.

This is what I understand from what folks have given me for information.
 
I have a 440 volt motor wired delta, that I run on 240 volt three phase for 10 years now. I see no noticeable loss of power or any heat generated. This is on a 29 spindle boring machine for wood. Saved having it rewound because it was a very compact motor.
Cheers
Martin
 
Another question.

Is anyone running a surface grinder, having the three motor systems I referenced earlier, on anything less than an extreme duty 5hp level converter? I've been told by one company that I should use this level converter yet another says that the system will run fine on the base level 3hp.

The system has a 1hp spindle motor, a 1/2hp hydraulic pump motor, and a lube pump motor that is maybe 1/4hp ,I can't find any reference to the hp of it but it only pushes lube oil to the ways.

Thoughts?

Thanks
 
I have a surface grinder as you describe, it has no trouble running on my 5 HP (homemade ) phase converter. When you add motors to the circuit, they all act as phase converters, adding, not subtracting from the converter's capacity. I see no need for an extreme duty unit, since there is no high starting load involved (like maybe an air compressor). Three phase motors in a hobby shop will rarely draw full load amps. I think the other company that told you that the 3 HP unit is sufficient is telling you the truth. The machine's nameplate lists full load amps as 7 on 230 volt supply; it is a Brown & Sharpe Micromaster.
 
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