Repulsion-Induction Motor / Drum Switch Wiring Woe...

Eddyde

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Hi All,

I scored a somewhat historical lathe, a couple of weeks ago. For the most part it is in great shape and only needs a little cleaning, lubrication and new belts. However, in the process of moving it, I had cut the wires to/from the motor and drum switch, I didn't id the wires as I should have (duh) since I thought it would be no biggie to figure out as the motor has a wiring schematic on the spec plate and I have wired several drum switches in the past... I also wanted to replace as much of the old wiring as possible, anyway.
Upon rewiring I have some uncertainties: First, I have no experience with Repulsion-Induction Motors hence, the diagrams on the motor plate are a little unclear to me, as to how it should be wired. Of the 2 diagrams, initially I thought one showed forward status and the other showed reverse, but the diagrams also show different interconnections on the motor, leading me to think the one on the left is for low voltage and the one on the right is for high voltage hook up, although no voltage or amps are stamped on that side of the plate. Further confusion as there are only 4 wires exposed in the motors junction box so none of those interconnects could be readily made, anyway. So I think, the left digram is the one I should follow, but I am somewhat confused buy the "X" pole representing the drum switch. I assume the status shown is "forward" but how would it look in reverse?
So far, I have searched the net and come up with little. One photo of an old paper schematic looks like it is the correct one but is torn and missing the half the circuit (as is always my luck).
I have determined T1 & T2 have continuity as does T3 & T4.
I have determined the switch pole configuration.
I hope someone here can assure me of the correct wiring?

IMG_2237.jpgIMG_2413 (1).jpgIMG_2424 (1).jpgIMG_2426 (1).jpgIMG_2427 (1).jpgIMG_2428 (1).jpgIMG_2429 (1).jpg

Many Thanks in advance.

Eddy
 
Hi Ed, I can help: You are correct the left and right diagrams are for low and high voltage, respectively. This motor may be only for 110 volt if there is no other terminal board deeper inside the case.
The "X" picture is the drum switch but the two swinging contacts or poles are not shown- you have to imagine the two poles of the switch swinging left or right for forward and reverse. I can do a sketch to clarify if you need one. Does the drum switch have a center off detent? If so you would run one line wire through the bottom contact for center off.
Mark
ps that's some really vintage stuff you've got there!
 
Important point: I don't believe the switch symbol shown on the motor directly translates to the pins on your drum switch-
I'll sketch it up and post it here- stay tuned
Mark
 
Hi Ed, I can help: You are correct the left and right diagrams are for low and high voltage, respectively. This motor may be only for 110 volt if there is no other terminal board deeper inside the case.
The "X" picture is the drum switch but the two swinging contacts or poles are not shown- you have to imagine the two poles of the switch swinging left or right for forward and reverse. I can do a sketch to clarify if you need one. Does the drum switch have a center off detent? If so you would run one line wire through the bottom contact for center off.
Mark
ps that's some really vintage stuff you've got there!
Thanks Mark,
Yes the drum switch is center off.
I did a bit more research and it seems the Repulsion-Induction Motor has two windings in the stator, a start and a run. the rotor is energized by inductance but its windings are connected to itself by brushes which disengage when it come up to speed. I had never heard of this arrangement before. Another thing I noticed, the amps are 7.2 and voltage is 110 so 792 watts, I think that is slightly over 1 hp. yet the motor is rated at only ¼ hp.? Guess either they severely underrated the motor or that design is very inefficient...
A drawing would be great, if its not too much trouble.
Many Thanks
Eddy
 
RI motors are antique and were used before the use of capacitors. They are wound rotor devices using brushes for startup that are shorted with a centrifugal arrangement once the motor reaches speed. These motors have great startup torque and reach speed quickly - therefore, the brushes seem to last forever.
 
That would be 1 HP at 100% efficiency but they never are.
Could you post a closer pic of the drum switch- same top view but closer? Thanks
Mark
 
That would be 1 HP at 100% efficiency but they never are.
Could you post a closer pic of the drum switch- same top view but closer? Thanks
Mark
Here ya go.
IMG_2436.jpg
Off
IMG_2437.jpg
Forward
IMG_2438.jpg
Reverse
IMG_2440.jpgIMG_2442.jpg
The whole thing is one casting!
IMG_2444.jpg
Please let me know if you need any more.
Thanks
Eddy
 
OK very good give me a few minutes-
Mark
ps I think you could bump-start Frankenstein with that switch
 
Here are two ways you could wire it Ed, "A" is the simplest and does not break the neutral line when off. "B" breaks both line wires when off.
You'll notice the Run and Start windings are interchangeable- swapping the ends of either one with respect to the other reverses the motor.
Mark S.RepMot1a.jpeg
I suspect it was wired like "B" before you cut it. If the motor was dual voltage you would want to use the "B" connection too for 220v.
 
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I beg to differ with most who posted on this; I am familiar with repulsion induction motors, and the only thing that can be done by connecting the motor wires is voltage, either 110 or 220 volts; to reverse these motors, the brush holders are shifted, there should be an access plate on the back end of the motor that exposes the brush holder and there would be a pointer and two marks, for CW and CCW rotation.
 
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