# Old 1 Ph motor



## backstay

I have a customer that would like to repair this 2 Hp motor. Ever see a start winding control like this? The brushes are a problem also.


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## kevink1955

If I remember they are called repulsion start, induction run motors. the brush rig gets lifted off the comuitator when the motor comes up to speed.

I have no idea how you are going to fix it.

They do make some cool noises on startup


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## tates1882

Isn't that the a brush lifter? I do believe to change rotation on that you have to rotate a small washer that changes the pole position.


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## backstay

kevink1955 said:


> If I remember they are called repulsion start, induction run motors. the brush rig gets lifted off the comuitator when the motor comes up to speed.
> 
> I have no idea how you are going to fix it.
> 
> They do make some cool noises on startup


The thing has a centrifugal device that pushes the round piece with the segments. My question is, what function do the segments perform?


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## Wirenuting

That's the drive motor for The Time Tunnel.
It was always shooting sparks and goofing this up.


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## JRaef

backstay said:


> The thing has a centrifugal device that pushes the round piece with the segments. My question is, what function do the segments perform?


During startup, a single phase motor does not have a way to determine the direction of rotation, so some other means must be used. One scheme was called a Repulsion / Induction motor. It started like a DC motor, with brushes and a commutator that determined the rotation, then the centrifugal arm lifted when it got to speed and it ran as an induction motor. The idea was, the brushes and commutator did not see as much wear and tear as a DC motor. Those "segments" are part of the commutator assembly, the part where the brushes make contact to provide field power to the rotor assembly.

These have not been made for probably 50+ years now, so most motor shop guys who knew how to fix them have likely retired. You will have to search around a lot.


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## backstay

JRaef said:


> During startup, a single phase motor does not have a way to determine the direction of rotation, so some other means must be used. One scheme was called a Repulsion / Induction motor. It started like a DC motor, with brushes and a commutator that determined the rotation, then the centrifugal arm lifted when it got to speed and it ran as an induction motor. The idea was, the brushes and commutator did not see as much wear and tear as a DC motor. Those "segments" are part of the commutator assembly, the part where the brushes make contact to provide field power to the rotor assembly.
> 
> These have not been made for probably 50+ years now, so most motor shop guys who knew how to fix them have likely retired. You will have to search around a lot.


Thanks for the theory lesson. But the small segments don't touch anything. This thing starts as a split phase not DC. But what do the segments do?


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## millelec

I've seen repulsion motors used for pipe organ blower motors. Older blowers had wood paddles on interior and couldn't handle the quicker start. my church is currently having its pipe organ renovated. had a talk on theory and operations w/the restorer. organ keyboards send digital signal to organ loft, signal gets translated to 12vdc, which operates solenoids allowing air flow to the pipes you have selected for those keys. guys are craftsmen.


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## Galt

I worked on several of these years ago and own one on an old air comp.the part you are referring to is part of the centrifugal mechanism that pushes the brushes off the comutator.


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## just the cowboy

The groove in the segments lock overe the brush rigging, look at the last picture. the four square lock at 90 deg apart fit inside the grooves. When the motor spins fast enough those segments expand and lets the spring push the brushs off the com. At least thats how the ones I worked on. Not easy to keep working


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## just the cowboy

The groove in the segments lock over the brush rigging, look at the last picture. the four square block at 90 deg apart fit inside the grooves. When the motor spins fast enough those segments expand and lets the spring push the brushs off the com. At least thats how the ones I worked on worked . Not easy to keep working 
Unless it is to repair a piece of equipment to keep orginal, replace it


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## circuitman1

if memory serves me right, those little segments are the shorting necklace. they come in when the motor gets up to speed & shorts the rotor so i becomes solid, so to speak.the 4 finger thing is for the brushes that short it out on start up, it moves away from the comuntator as it speeds up so not to wear out the brushes, this is where the little segments do there job.i belive it is hooked together by a spring. they are extremly hi torgue starting & are work horses.they can be repaired , but as someone said most of these guys have long since retired.brushes can still be found, & possibly the spring for the segments. ill take some looking though. how did it come apart like that?if you have one brush, you may be able to find replacements at an electric motor shop, if not ohio carbon brush may be able to help. also you will need to know the position of the brush assembly, this is what makes it go forwards are backwards. they should be a scribe mark on the plates for aligment, generally have to loosen a screw, to turn it for a direction. if you are not sure you will have to use trial & error. you will know when it's right.:thumbsup:


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## itsunclebill

Most of these old motors had brushes that rode on the commutator all the time. The position of the brushes determined starting rotation. Once the motor got up to a certain speed the segments were pushed against the commutator by centrifugal force and essentially turned the rotor into squirrel cage type where the windings are all shorted together.

The springs need to be in good shape so the segments don't short the windings too soon as this affects the starting torque and can prevent the motor from starting at all. The segments need to be in good shape (not burned at the contact point) as does the inside of the commutator where they make contact so the motor will develop full power and keep the brushes from carrying current they weren't designed for. 

A motor shop can rewind the windings in the body of the motor. The armature would be a very special and expensive rebuild especially if the commutator is bad. Eurton Electric in CA does this stuff and will quote repairs.


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## BT Leveque

I got to this forum thread because I was searching for some good diagrams of repulsion induction motors for another member of another forum, Old Wood Working Machines (OWWM). I joined so I could see the pictures. It seems like a great forum! Even though I'm not an electrician by trade, it sure seemed like it sometimes when I worked in industrial/commercial HVAC!

I'm very familiar with Repulsion start/Induction run motors and extremely familiar with the Wagner motor in this thread since I worked on a boat load of them on old Johnson Controls pneumatic control air stations. I’ve also seen a bunch of them on old wood working machines (my hobby). I realize this is an old post but I figured I'd post my knowledge for others that may find their way here like I did! For the purpose of this post I am referencing only the Wagner brush lifting repulsion/induction motor like the motor pictured above. I know Westinghouse and GE had their versions too. There is another form of this motor that is "brush riding" but I won't refer to that one here. Dunlap, Duro, and I believe GE also, had a model line of 'brush riding' repulsion/induction motors and while the theory is the same, the function is a little different.

I thought these motors were awesome! They are way cool sounding on startup and very cool overall :thumbup1:. They have fantastic start torque and a great power factor for a single phase motor. Better than most single phase motors today, even PSC motors. However, the brush assemblies and commutator are maintenance intensive and the motors were very heavy and very expensive to manufacture. That's why they're no longer made and haven't been since the advent of the electrolytic capacitor and capacitor start/induction run motors became more prevalent in the 1930's and forward.

These motors, as the name implies, are both repulsion and induction motors but not at the same time. They are repulsion motors during the motor startup and induction motors once they’re above 80% running speed. The rotor is wound with many short windings making up many poles around the armature. Thus they are sometimes referred to as a 'wound rotor' motor. They have one winding set on the armature for every set of two 180* spaced commutator conductors. The windings are wound over the squirrel cage induction windings of the rotor.


There are separate field windings on the stator. The stator windings are the only windings connected to incoming line voltage. Note that the armature windings are not powered from the line directly like universal ac/dc or series dc motors are. They are powered by induction from the field stator windings. There will be as many shorting brushes for the commutator as there are field poles in the stator (usually four creating an 1800 rpm synchronous speed/1725 rpm induction speed motor) The brushes that contact the commutator short a set of windings on the armature that are 180* apart. The windings that are shorted are wound to be 'like magnetic poles' of the field windings they are in line with, thereby creating the repulsing force. This gives the repulsion/induction motor 3-4 times the starting torque of a split phase motor and many more times that of a shaded pole motor. This very high starting torque made them perfect for high starting torque loads using single phase power. They are usually reversible by changing the axis of the brush yoke by rotating it to the left or right. Many of them are also dual voltage 110/220 VAC, 1 PH.


Once the motor is up to about 80% speed, the flyweights of the centrifugal mechanism attached to the shaft, on the opposite bell end from the commutator, fly out pushing the push rods that go through the armature into the spring barrel which has the shorting necklace wrapped around it. At rest and while starting, the shorting necklace is out of contact with the commutator while the shorting brushes are in contact with the commutator. When the motor comes up to speed and the push rods push the spring barrel toward the commutator, the shorting necklace shorts the entire interior diameter of the commutator thereby shorting all the armature windings and collapsing the stator induced repulsion fields created by the armature. At the same time the shorting necklace shorts the commutator, the shorting brush yoke is pushed back from the face of the commutator lifting the brushes off the commutator. This is where the term "brush lifting" comes from. Now there are no longer repulsive magnetic fields created by the armature windings that were induced from the field windings. In their place is an inductive field induced into the squirrel cage windings of the rotor from the stator and the motor is strictly an induction run motor from that point on while power is applied to the motor.


So there is my explanation of all facets of the Wagner repulsion/induction motor. Other brands of induction/repulsion motors operate in a similar fashion. I hope I’ve demystified the motor for you. Thanks for reading, I know it was long windinged… err…winded!
Peace,
Brian


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## RIVETER

backstay said:


> I have a customer that would like to repair this 2 Hp motor. Ever see a start winding control like this? The brushes are a problem also.
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Many, WHAT did you do?


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## telsa

These motors were the standard for floor sanding machines... the old drum machines.

As described, the start up torque is intense.

I have a museum piece in my garage -- right now. It's about 3 ph at 208 VAC. It's built like a tank, looks good for another century.


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