B&S #13 advise please

[wildcatter]

Hi guys, I am looking at purchasing a #13 universal grinder ser. #525-13-1509 , I am not sure of the year it was made . I have not had a chance to look at it yet, but my question is about the power supply. Currently I think it is wired for 440v, 3ph. If I understand correctly from the op.manual they have 3 motors? A 1hp, a 1/4 hp and a 1/6 hp . I only have single ph in my shop, 110v, and 220v. Would a VFD be able to power this grinder ? If so would it have to be rated for 2hp? Or is a rotary ph converter necessary ? Thanks in advance for any help. I have no experience with 3 ph or VFD's.
Dave

 

[markba633csi]

Can you reconfigure any or all the motors to 220 volt? Normally you would want a RPC for a multiple motor situation like that but I don't believe they can step up the voltage from 220 to 440. If you can get the main motor to run on 220 then you could use a VFD for that one and perhaps change out the other ones for single phase units. Or perhaps use static phase converters for those two smaller ones, at 2/3 power, IF they can be wired for 220.
A step up transformer is another possibility but it starts getting complicated and expensive
VFDs are best used for single motors. There may be VFDs that can step up from 220 to 440v- I'm sure they won't be cheap
-Mark

 

[Nutfarmer]

I am looking at the same thing with a monoset grinder. What I am thinking is to change the motors to 220 3 phase and change the control transformer to run on 220. Then I can run it off of my rotary phase converter. Thought about using two vfd after changing over the motors , but didn’t like the idea of having to rewire all the controls. If you do purchase the grinder show us your solution. My project is going to have to wait until next winter

 

[brino]

If I understand correctly from the op.manual they have 3 motors? A 1hp, a 1/4 hp and a 1/6 hp

It's likely that the smaller motors are for power feed and coolant pump.
You probably do NOT want those speed controlled along with the main motor.
Brian

 

[wildcatter]

I know the 1hp motor can be re-wired for 220 but not sure about the 2 smaller ones. I think the two smaller ones run the table and the headstock and the 1hp is on the spindle. I would likely not need to vary the speed but the number of motors is possibly an issue and of course the voltage of the smaller motors.

 

[wildcatter]

I checked the manual again and there is no wiring diagram. I would have gone to look at it but we got a nasty snow storm yesterday so travel is out for now.

 

[wildcatter]

Well, I bought the grinder and got it home. Heavy beast. Finally got the power issue sorted out. Due to the fact the grinder has 3 motors I eliminated VFDs as the best option. Bought an American Rotary 5hp rotary converter and wired it up. The machine had already been re-wired from 440v to 220v, and the transformer had been re-wired as well, however the person who did this never changed the heaters for the overload relays so I had to do that. Seems to be working great now.