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Motor Generator Drive

Andy McClellan

Plastic
Joined
Sep 9, 2002
Location
blountville, tn us
I got my 10EE changed from 440v to 220v. When I started it up the generator drive starts just fine. I went ahead and turned the spindle on and it starts to speed up but then it will slow back down. There is a very bright arc from the brushes on the generator when you do this. Was wondering if anyone has seen this problem and what they might have done to fix it.
 
There's arcs and different arcs. What is yours like?

If it is a ring around the commutator, then you may need to clean between the bars, or you could have an open bar connection.

If you get a lot of general arcing, there may be a problem with the brush placement, brush wear, high mica, burnt bars, compensating windings, or excessive current draw.
 
I had the same thing happening with mine when I first got it - it was wired for 380V, but connected to 220V. Are you sure you got the wiring change right? If the AC drive motor is lacking torque it slows down when you engage drive, and all the voltages drop. This may again trip the relays, and sparks fly in the commutator on the drive motor.
 
I did some more checking today. The generator drive is putting out 120v and that doesn't change any when you engage the spindle. I noticed that one of the relays in the dc motor control box will start to engage but then it pops out. Ever time the relay starts to engage the spindle motor will rev up and then back down. I have voltage going into the control box but you don't have a steady voltage coming out to the motor. Any ideas would be appreciated.
 
Is the generator running in the right direction? You may have swapped two phases when connecting. I think there is an arrow on the pulley on the exiter (under cover on the tailstock end)
 
Yes the generator is running in the right direction by the arrow on the motor. The generator end of the machine seems to be working fine. The problem seems to be in the dc motor control box.
 
Andy,

You say that the generator is putting out 120V. That would be right for the exciter (the belt driven unit that sits on top of the M-G case). The exciter provides the DC voltage that runs all of the relays. You should see a pretty steady voltage across the E1 & E2 terminals. The generator output is on the GA1 and GA2 terminals and it should vary with spindle speed.

Check the resistance across all of the relay contacts, you may have a burned contact. None of the relays should be operating except when the spindle is turned on, off or reversed.

Cal
 








 
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