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Is This Wired For 110 Or 220?

TomS

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#31
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.
 

TomS

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#32
Went ahead and checked voltage across U and M5 and V and M5. Got 240v across each. Anything else I can check?

Tom S.
 

TomS

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#33
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.
 

master53yoda

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#34
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
 

master53yoda

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#35
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

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#39
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.
 

TomS

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#41
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.
You are correct in that I get 240v across U, V and M5 one at a time.

Tom S.
 

master53yoda

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#43
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.
you are correct with the transformer connections if that is how they are ID. are the jumpers on both contractors and did i label the internal contacts in the contractors the way they really are.

About the only thing left , is the possibility that one of the windings in the motor has the numbers reversed and it is working against the other winding. Try reversing wires 1 and 3 from the motor, use the on /off switch to just jog the motor. if it seems to start OK go ahead and turn it on and see if it comes up to speed quickly, like it did on 110.

if the windings are reversed they can cancel each other out, its kind of like putting one battery in backwards, and the only thing working is the start winding. and once it drops out the motor would have very little torque as the magnetic fields generated by the windings cancel each other with the exception of the current from the rotating rotor.

Art B
 

TomS

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#44
you are correct with the transformer connections if that is how they are ID. are the jumpers on both contractors and did i label the internal contacts in the contractors the way they really are.

About the only thing left , is the possibility that one of the windings in the motor has the numbers reversed and it is working against the other winding. Try reversing wires 1 and 3 from the motor, use the on /off switch to just jog the motor. if it seems to start OK go ahead and turn it on and see if it comes up to speed quickly, like it did on 110.

if the windings are reversed they can cancel each other out, its kind of like putting one battery in backwards, and the only thing working is the start winding. and once it drops out the motor would have very little torque as the magnetic fields generated by the windings cancel each other with the exception of the current from the rotating rotor.

Art B
Thanks to everyone that has taken the time to share their thoughts and expertise. Without your help I would have had to hire an electrician to sort this out. I think we're getting close.

The jumpers are on the left/reversing contactor only. Other than the jumpers on the right/forward contactor your drawing appears to be accurate.

I'll swap wires 1 and three and see what happens. Could it be a bad motor winding causing this low torque situation?

Tom S.
 

master53yoda

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#45
on series connected windings they electrically must be ok or you wouldn't get anything.

I am almost positive that the jumpers need to be on the right contactor. you might want to pop the top of that contactor and see if the contacts are configured the way i show them in my drawing. the right contactor will need those jumpers for the correct operation.

Art B
 

TomS

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#46
I swapped wires #1 and # 3. Motor hummed/groaned and that's about it. I called a local motor shop this morning that I've done work with and he said bring it in and he will test it. My house is full of grand kids this weekend and then I'm headed out of town for the holidays on Monday and won't be back until after the first of the year. So this is going to sit until I get back. I'll will post the motor test results.

Tom S.
 

master53yoda

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#47
Well that leaves putting the jumpers in the other contactor as the last thing to do. Have a good holiday and we'll see how things are after the new year

Art B
 

TomS

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#48
Happy Holidays everyone and thanks for your help. I'll let you know what I find out at the motor shop.

Tom S.
 

TomS

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#49
I took the motor to a local motor shop today to have it tested. Found that the run capacitor (metal case) was shorting to the motor housing. The technician said shorted capacitors aren't common but it does happen. Replaced the capacitor and wired it back up. Runs great! Took a .050" DOC at .008" per evolution in mild steel and the motor didn't change rpm.

Thanks again to everyone that helped with comments and recommendations. I learned a few things along the way.

Tom S.
 

markba633csi

Active Member
Active Member
#50
Tom: Glad you got it fixed; it's not entirely clear to me what the shorted cap was doing (was this a start cap or a run cap?) electrically to the motor performance.
Sounds like it was stealing current from the run windings somehow. Anyhow, have fun! Make chips!
Mark S.
 

TomS

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#51
Tom: Glad you got it fixed; it's not entirely clear to me what the shorted cap was doing (was this a start cap or a run cap?) electrically to the motor performance.
Sounds like it was stealing current from the run windings somehow. Anyhow, have fun! Make chips!
Mark S.
It was the run capacitor.

Tom S.