Is This Wired For 110 Or 220?

Set up a 2" piece of round stock in the lathe. Took about a .040" DOC at about .008" IPR feed rate. Running at 425 rpm it bogged the motor down significantly. Measured the input voltage across terminals R and S and got 240v.

To verify if the motor is getting 240v do I measure across terminals U and M5 and V and M5?

Tom S.
 
Went ahead and checked voltage across U and M5 and V and M5. Got 240v across each. Anything else I can check?

Tom S.
 
Had another thought. Could it be the motor? This is the original motor (vintage 1989) and it's Asian manufactured. It's being fed 240v but seems like it's running on 110v. Maybe one of the windings went south? Just guessing at this point.

Tom S.
 
I verified that #2, #3 and #A2 are connected together. I also went back over the electric box wiring, specifically the contactors, because of changing out the reversing contactor at the same time as changing over to 220v operation. I did find something but not sure it resolves the issue at hand.

Look at the revised diagram attached below. You note that the transformer wiring is different. This change reflects the change from 110v input power to 220v input power. That's OK and understandable. Take a look at the left (reversing) contactor. Note the two jumpers. These weren't on the diagram that was attached to my first post. I don't think this is the problem as the jumpers allow input power to flow from the reversing contactor to the forward contactor. Am I off base on this?

Tom S.

Is there a jumper between H2 and H3 on the transformer. For high voltage that is the only jumper that should be on the transformer.
It also looks like there should be a set of jumpers on the other contactor or the transformer is never powered. But then it shouldn't work at all???????

Does the welder work ok on high amp settings. Checking the operating voltage is still the only way to eliminate it as a problem.
Art B
 
I just read about getting 240v across both U and V to m5 it only should be from one of them at a time. without the contactor jumpers i asked about on the last post it could be putting the transformer in series with the windings and it would act like choke on the motor. That may be what is wrong. I'm going to print and modify the drawing to the way I think it should be. give me about 45 minutes and I'll get back.
 
toms lathe diagram 2.jpg

I added how i think the switching in the lathe is set up and the motor wiring. the jumpers are in red I also added the contacts and the contactor coils.

Art B
 

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I think Yoda's got it- the contactor (or transformer) is in series with the motor, cutting the current
MS
 
Is there a jumper between H2 and H3 on the transformer. For high voltage that is the only jumper that should be on the transformer.
It also looks like there should be a set of jumpers on the other contactor or the transformer is never powered. But then it shouldn't work at all???????

Does the welder work ok on high amp settings. Checking the operating voltage is still the only way to eliminate it as a problem.
Art B

There isn't a jumper on the transformer. There are voltage designations for each of the transformer terminals. H1 is 0, H2 is 110, H3 is 220, and H4 is 240. My understanding of the circuitry is that H1 is the neutral and line voltage is connected to one of the other three terminals depending on your input voltage. In my case it's 240v.

I did check the operating voltage at stand still and under load. In both instances it was 240v+.

Tom S.
 
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