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Question about GE Repulsion Induction motor

janc

Aluminum
Joined
Dec 12, 2012
Location
NW Ca USA
The question is, can I swap the end shields/bells and armature in the stator on this motor and still have it function properly? the purpose being to have the wiring in a more convenient position. This is a motor I have had in spares for many years and finally have a need for it, gave it a cleaning and tune up, and it is in good shape and runs as it should. Brushes are getting a little thin, but I should be able to find a set when needed.
 

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The OP's reason for asking about turning the motor around is to get the wiring connections on the side giving cleaner installation. On electric motors and generators, the slang term for the wiring connection is the peckerhead. I have the same GE R-I motor on my camelback drill. The stator housing has the leads coming out one side of it. Without getting into the motor, from what I recall, the brush rigging and shorting bar are all mounted on the end bell casting. The bolt circles for both end bells look the same. The bolts are NOT thru bolts, but appear to be short bolts tapped into the flanges on the stator casting.

From the OP's photo, he had the motor apart to varnish the windings with Glyptal. If there is no difference in the end turns on the stator windings and the machining of the fits of the end bells & stator ends are interchangeable, the OP's idea is physically do-able. However, I am a mere mechanical engineer, and my electrical knowledge is very limited. Since the motor is an AC motor and there is no hard wiring between the brush rigging and the stator windings, it would seem that the OP's idea would work.

Looking at my old camelback drill (now partially buried for winter with a Lincoln engine driven welder hard against one side and a Harley close to the other side and a bunch more stuff wedged in), the peckerhead is on the LEFT side of the stator as you face the drive/shaft end of the motor. My own thoughts on the OP's motor are to "leave well enough alone". Some conduit fittings and conduit or "sealtite flex" will handle getting the wiring routed around the motor without risking any radical changes.

Years ago, on my first engineering job, I had to design some foundations for pumps. The year was 1972, and the field project super was an old timer who came up the hard way. I looked in a reference book for the NEMA frame details, and directed the electricials to stub up the conduits on the correct side of the foundations to line up with the peckerheads on the pump motors. The old project super was having none of that. He did not trust me or my reference book, and said he'd had too many jobs where the conduits were stubbed up on the wrong side of concrete foundations... conduit snaking around the back of a foundation to the get the peckerhead side of the motors looked like hell and he'd be damned if he'd take the chance on this job. He had me re-draw things and have the electricians bring the conduits up out of the concrete slabs on the rear end of each pump foundation, on the centerline of the motors/pumps. In that way, it would be a simple matter to swing the conduit down the correct side of the foundation, and it wouldn't look like a foul up. In the ensuing years of my career, I've had to deal with motors having peckerheads on the wrong side, going into existing locations (newer NEMA frames vs older frame series, or different types of motors). Sealtite flex and conduit and a little extra jog or two in the routing were what it took.
 
I decided to keep the armature/stator position the same, but did give the end bells a 1/4 turn, so the oil cellars will be right side up as the motor will be mounted on a vertical surface.
As noted by others, the brush assembly is indexed on the end bell, with positions for both direction, and a index hole in between, which by my research is a neutral position, why a neutral position?
 
janc:

If you need replacement brushes for the G.E. R-I motor, contact: Helwig Carbon. Helwig manufactures brushes from scratch, and has numerous stock sizes/configurations of brushes as well. I worked in a powerplant, and Helwig furnished all the brushes for the big generators and exciters. When I needed to replace the brushes in the GE R-I motor on my camelback drill, I got in touch with Helwig. The engineer asked me the type of motor, voltage, amperage, and asked me the dimensions of the brushes and where the pigtail was located, length, end termination on it, etc. A set of brushes ran me 65 bucks. Money well spent, because the failing brushes in the R-I motor used to arc and sputter and it reached the point where I had to give the motor shaft (has a pinion gear driving a bull gear on the lower cone pulley shaft) a spin to get the motor to start. Cleaning the brushes and commutator and making sure they were free in the brush holders did no good when the brushes were that far worn.

BTW: years ago, as a kid, I innocently called the rotating element of an AC induction motor the "armature". I was about 12 and buying a vee belt in an electric motor repair shop. The mechanics who heard me use that term pulled me aside and gave me a quick lesson in the anatomy and principals of AC induction motors, and told me the rotating element was either the "rotor" or the "rotating field", and the stationary windings were the "stator".
 
I had a similar experience with Helwig, not only did they ask the same questions about details, they wanted photos of the brushes and acknowledge receiving email, waiting for a quote now, nice to deal with a company like that.
 
Some years ago I overhauled a perhap similar motor, angled brushes so single direction, but an adjustable brush assembly. The brush center position gave 1800 rpm, the two extremes sped up or reduced rpm by something like 20%, though the motor was happier in the +/- 10 to 15% range. Was a very heavy unit for its power, looked like it was capable of a lot of torque.
 








 
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