Need Help Replacing Motor On Enco 110-2075 Engine Lathe

Lets say the thermal overload trips when set with the bypassed direction engaged. The motor then slows down to the point where the centrifugal switch engages. This then puts one half of the run winding in series with the start winding. I'm not sure what would happen but I suspect with a light load it would keep cycling on an off and a heavy load would never get up to speed and eventually smoke the motor.

To the original poster I do believe there is a way to wire KM2 & KM3 to work with this motor. I suspect it will require small changes to the wiring of KM1 also. What I don't know for sure is what F-R is in the original diagram. The actual connections to contactors Km1, Km2 & Km3 are also a bit of a mystery so I would not be able to tell you which terminals to use. For these two reasons I am a bit reluctant to post any updated diagrams without knowing for sure what that stuff is. If you weren't 2700 miles away i would be in a better position to help.
 
The motor contactor has a separate thermal overload. Normally you would not use a motor with its own separate thermal oveload in this control system. Baldor motors tend to be very reliable and durable, so the chance of the centrifugal switch failing in the near future is unlikely. I agree with Rich that the right way would be to wire it per the Baldoe wiring diagram, but when I tried to do map out the wiring diagrams, it would take two 4 pole contactors and more significant wiring changes. The problem is that without being there and mapping things out, it could be a bigger mess and go up in smoke. So I think I would start simple and see how it works, then you can weigh in on the alternate options. Buy a motor that fits the machine wiring diagram without rewiring, rewiring the contactors or going 3 phase with a VFD, etc. F-R seems to be the motor thermal overload that interrupts power through the E-Stop going to the motor contactors.
 
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Trying to follow along here: So in the original config U and V were the run legs and Z1 and Z2 were the start legs. U and V were being reversed by the two relays/contactors Km2 and Km3. Correct?
What is that FR symbol with dotted line in series with the U and V legs?
Mark S.

My suggestion for discussion:
3-2-5 connected
8 to Z1
1 to V
4 to V (reverse lines if FWD/REV are wrong)
insulate Z2

Contactors will switch phase of the line wires.
Start coil will stay the same phase and 120v to the junction of the two run coils

The only correction would be 1 to U which i think i saw that you already caught. I agree with the need to connect 5 to the 3-2 connection, in connecting one of the start leads to center of the run winding and the other to Z1 the controls are leaving the start windings in phase with the incoming power and reversing the run windings in relation to the incoming power.

The [R] reference points in the U and V wires are the current overloads in the contactors. When they overload thier control switch removes power from the KM1 primary relay shutting down the motor. They replace the thermal over load in the motor. In the baldor diagram the thermal overload is set to operate on 110 current and would never trip on 240 volt currents In the picture in the beginning post, the diagram from the motor cap the thermal protection from baldor is disconnected and not used in the high voltage connections, they are relying on the controls system to detect overload conditions.

Art B
 
this picture has the FR overloads, the setting should be set to match the Amp draw that is on the motor name plate for 240 volts

Art B

overload setting.png
 
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So for the 220v case, I wonder why Baldor didn't provide a bypass for the thermal? They don't bring out the #3 pin on the thermal (wht/yel)?
Silly guys. Go back to your room.
Mark S.
 
Robert (cannon fodder) you still there? I think I have a solution for you: connect 2 and 3 and 5 together on the motor. Connect U and V to 1 and 4. Then connect 8 to Z1. If the forward/reverse is backward disconnect 8 from Z1 and connect it to Z2 instead. Should work.
Everyone else: Jim this is a repeat of your earlier idea. This leaves the run windings being both reversed and thermal'ed externally. Start winding always gets 110 cuz it's from the run winding midpoint to one end of 220. If you wanted to be a purist you could short yel and wht/yel on the motor thermal.
Robert make sure you have the ground wire connected to the motor, in addition to the above stuff.
 
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Look at this, I think it will work if you're so inclined to rewire the contactors. I'm not sure if the contactor numbers are correct and I didn't research which direction they are. The main thing would be to make sure you run the control wire for a direction through the opposite direction contact for an electrical interlock. I also assumed that the top contactor only provides power after a direction is selected.
If it isn't correct I'm sure someone will let me know ;).
 

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It looks to me also that the Baldor thermal receives the same current for either 110 or 220 volt connection; sees only 1 run winding's worth of current in either case.
It's too bad if Robert jettisoned himself- his electrical ignorance was in danger of being diluted :)
Mark S.
PS Sorry Robert if us eggheads took too long, it happens sometimes.
 
Hello gentlemen!!!
No, I haven't left. Weekends are my workweek and I was very busy. Sorry about the lack of communication.

I can not open jim18655's pdf. My browser begins to open a new tab, but then disappears. Can you repost?
I will set up the motor according to Mark's suggestion and get back to you guys.

You guys have great energy and are a great resource, I appreciate it so much.

I also have a new contact who is going to bring over a Chinese manufactured motor that is perhaps jumpered together in the same fashion as the original motor was (that is, it looks similar to the first photo in this post).

Thank you again, I'll let you know,

CannonFodder (Robert)

P.S. My electrical ignorance seems to be doing fine, my head is swimming and appears normal in every respect :)
 
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