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motor wires unidentifiable

SE18

Cast Iron
Joined
Feb 13, 2012
Location
N. Virginia USA
Hi all, this isn't a question about wiring the Furnas Drum Switch (RSB4 style) for 9A SB.

I've got the wiring diagram here (see photo) from when I pulled the wires.

However, I forgot to identify the motor wires (see photo).

So I guess my question is, which 4 wires from the motor connect with which of the 4 wires from the drum switch?

For the outlet, I assume ground goes to ground and the other 2 wires can go in either spot labeled outlet; so the main problem lies with the motor to drum switch connection.

With 4 wires, that gives me just 1 out of 16 chances of guessing correctly, and I'm afraid if I guess wrong, something dire will occur. BTW, all 4 wires have been cut in the photo.

The motor, btw, has a large capacitor, made by GE, looks really old, 7.5A, 1715 rpm, 60 cy, 1 phase, 120V

Any help will be appreciated! BTW, I was replacing frayed wiring.DSC03621.jpgmotor GE.jpg
 
No problem. They should be 1, 2 and 3. Or if no numbers at all there still should only be three with bands, those will be your motor leads. If no numbers , using a meeter to measure resistance would be the best way to ID the leads. But having 3 out of 4 wires with metal bands is a purty safe bet.
KW
 
Screen shot 2012-03-14 at 8.31.10 AM.jpgHi KW, I'm not home to see the lathe and the bands yet (I see them in the photo I took but too far away to read); but I did run across a diagram that has exactly the same specs as my motor and the drum switch is wired exactly the same; so I'm thinking if it qwaks like a duck, it must be...

Hopefully then, the bands will be numbered with at least 3 numbers and if the diagram's numbers correspond with the real way to wire the motor, it should be cherry... perhaps

Dave
 
I'm back and just took a look; each of the wires has a brass tag (similar to a bird tag). T1, T2, T3, T4

Very reassuring!!

Do you think that the diagram I posted might link each of those 4 wires???

I expect to get to work on this tomorrow, as this is the last restoration phase of my 9A

Much thanks, KW, for alerting me to this identifier method, which saved my bacon.

DaveV
 
Does the motor not have a wiring diagram tag on it?

My 9" came with a drum switch not wired but ten minutes looking at the motor diagram tag and the switch diagram tag plus five minutes to rewire and all worked.
 
DSC03934.jpgDSC03935.jpgDSC03936.jpgDSC03937.jpgHi Ken, I didn't notice a diagram but today I'm going to be removing the motor for exterior cleaning (counterstock is already waiting for a kerosene bath), so I will examine every part of the motor without tearing it apart or opening it.

The inside of the drum switch has diagrams for split, 2, 3 phase but it looks to be generic and not meant for this particular wiring diagram. The original wiring had 6 wires. Two were tied off so my guess is that at one time, this furnace switch may have been used with a different motor.

Anyway, here's the diagram inside the drum switch.

BTW, I do plan to replace the capacitor. Someone said Grange has them but I need to get some gits from M-C so I'll check if they have any caps.

Anyway, I'm not going to turn on any power until I am sure of the wiring and hunt for a diagram.

This is sort of like hunting for the pirate treasure map. LOL
 
DSC03942.jpgDSC03943.jpgDSC03944.jpgDSC03945.jpgDSC03946.jpgEverything is apart now so I can see all sides of motor. No diagram, just some hard to read stuff.

GE schenectady Patent 2032926 (Looked it up and no diagram just some verbiage about contacts)

1.5099122AA1

Model 5KO63AC494
Type KC
PH1
CYC 60
Rise 5800
Rating CON
1/2HP
A 7.5
RPM 1725

I'll wait for 2 days before wiring and testing the motor to see if anyone has any additional comments or words of advice.

Thanks again!

DaveV
 
Searching four wire motors suggested that if it's 110 only it maybe reversible but if it's 110/220 probably not.

I would suggest taking it to a shop to check and if it's not reversible they may have a suitable used replacement for not much $.
 
Hi,

Your motor seems similar to the one that Paula had on her lathe. Check this thread:

http://www.practicalmachinist.com/vb/south-bend-lathes/1947-model-9a-128005/index5.html

In particular you have that relay that's attached to the motor. That's kind of a special feature that many AC motors don't have. It might be GE specific.

Typically, to reverse an AC motor, you first shut it down, wait for it to stop, and then turn it on in the reverse direction.

This relay design apparently bypasses that, in the sense, you can throw the motor into the opposite direction without waiting for it to stop. It will slow down on it's own and then reverse direction.

Read through that thread and you might find helpful information. Paula had it wired kind of weird, in the sense that the Neutral wire was not running through the drum switch, but going straight to the motor. It seems weird because the wiring on other lathes I've seen so far has the Hot and Neutral both going to the drum switch, and both lines are disconnected from the motor when the drum switch is in the off position.

But, whatever works.

Good luck.
 
Thanks; Paula's is different; mine has 4 wires coming out of the motor. I should have mentioned that I had the motor and lathe running before refurbishing it. You CAN throw the drum from forward to reverse while it is still moving. I did it by accident. I don't think that is recommended? Or is it?

Last night I removed the bolts that hold the capacitor to the motor, as I was going to purchase a new cap; not that anything is wrong with this one, just old. However, I didn't figure out how to remove the wires from the capacitor and probably will just leave it on as I don't know how to remove it.

The photoshop diagram I created at the beginning of this post is exactly how the drum switch was wired prior to me removing the worn asbestos wiring. My only question was which of the 4 wires from the drum went to which of the 4 wires coming out of the motor. We'll see tomorrow, if I get around to wiring it. Hopefully it won't explode in the garage and damage my wife's car. I've already been dropping stuff on her car.

BTW, it is amazing how similar Paula's motor is. Only difference I can tell is hers has an extra wire from the motor (5 wires); also, her's is 1/4HP 3.8A and mine is 1/2HP at 7.5A

DaveV
 
Hi Dave,

The capacitor on the motor I'm working on had the wires soldered to the terminals. This might be the case with yours as well. If you really need to remove it, get a soldering iron, heat the solder and pull the wire out. Then use solder wick to clean the old solder off. I do recommend wearing safety glasses when desoldering loose wires. Sometimes loose wires like that have a tendency to spring out once they break loose, at which point the liquid solder that is still on them goes flying off into your face. It's happened to me, I've seen it happen to others.

Since you have 4 wires coming out of the motor, then this schematic that was posted on Paula's thread will probably match your motor.

DgVaC.jpg


So forget the drum switch at this point. First step is to figure out which wire is which. Your terminal wires were labled T1, T2, T3, T4. Forget those names for the moment. I've labeled the wires on the schematic R1, R2, S1, S2, as it will be simpler to explain things using those labels.

R1 and R2 are the wires connected to the Run winding.

S1 and S2 are the wires connected to the Start winding.

A single phase motor only needs 1 winding to truly run.

DQAeH.png


In this image, there is only the run winding that is connected to the power line. If it was a 230V motor, then the power Line is labled L1 and L2. If you are using 110V, than the designations are Hot and Neutral. The Hot wire is the black one, and Neutral is the white one. So R1 is connected to L1/Hot and R2 is connected to L2/Neutral. This could be reversed (L1=R2, L2=R1), and it won't make one bit of difference because the power line supplies alternating current. The problem with this setup is that the motor will not self start. That is to say, it will not turn on it's own and and will just sit there humming. One way to start it would be to hook it up like that, and then once the motor is just sitting there humming, put a hand crank on the rotor shaft, and crank it in whatever directions you want the motor to turn. Kind of like they used to start old car engines. If you spin it real fast by hand, and then release the hand crank, the motor will then continue running on its own, due to the momentum of the rotor.

But you don't want to do that each time you want to start your lathe.

So, this is where the start winding comes in.

J0A9H.png


In this image the start winding is connected in parallel with the run winding. L1=R1=S1 and L2=R2=S2. There is a centrifugal switch that is in series
with the start winding. When the motor is not spinning, this switch is closed. When you apply power to this motor in this setup, the start winding, and
the run winding will both have current running through them. As the motor accelerates and reaches about 75% of it's top speed, the centrifugal switch will open, and the start winding will be disconnected from L1. At this point, the start winding will no longer have any current going through it, and only the run winding will continue to spin the rotor, just as if the start winding wasn't even there. The problem with this setup however, is that you are only using single phase power. That is, the current going through the start winding, and run winding will be exactly the same, and both coils are in phase. This is not sufficient to start the motor from a full stop. In order for the start winding to start turning the rotor, it needs to be out of phase with the run winding, that is to say, there must be a delay between the currents in both windings. There are 3 ways to achieve this.

1. Use multiphase power from the power company, which you don't have.
2. Make the start and run windings different. This is done in split phase motors. They use a smaller diameter wire for the start winding, which increases its resistance. This difference in resistance of the start and run windings puts them out of phase.
3. Keep the windings the same, but add a capacitor in series with the start winding. This capacitor will cause the current through the start winding to be out of phase with the current through the run winding. This is shown in the image below, and this is called a capacitor start motor.

iGz17.png


This will run exactly the same way as the split phase motor without the capacitor. Only difference is that the windings are the same, which produces higher starting torque, and that is a plus in certain applications. The extra capacitor also increase the price of the motor.

As with the polarity of the run winding relative to the power line, the polarity of the start winding is not important to get the motor started. However, the polarity of the start winding relative to the run winding will decide on which direction the motor spins: clockwise or counterclockwise. To figure this out, you do it by trial and error. Simply hook it up as in the above figure, run it, and note the direction of rotation. Then you reverse the polarity of the start winding as shown below.

DJoLT.png


Now:

S1 is connected to L2,R2
S2 is connected to L1,R1

This will reverse the direction of the motor.

----

The last piece of the puzzle is the relay you have. Many motors don't have that. From what people said on Paula's thread, this relay allows the motor to be instantly reversed. You did that already by throwing the motor from forward straight to reverse, and you said it worked. Well, there you go. I'm not sure what would happen if you did that to a motor without the relay, but I'm guessing the motor would simply not reverse and continue running in the same direction, simply because the starting coil would still be disconnected by the centrifugal switch. Anyways, I don't think you have to worry much about the relay, other than maybe take it off the motor, and clean any oxides of the relay contacts. Relays and switches tend to arc and bounce when they are closed, and over time some oxidation/carbon will develop on the surface. Cleaning with electrical contact cleaner, or alcohol, or just very light sanding should do the trick and clean up the contacts if they look really bad.

So to figure out which of the 4 wires is which you will need an Ohm meter to measure resistance. You said the terminals you had were labeled T1, T2, T3, T4. So you need to measure the resistance between all possible pairs of the 4 wires you got:

T1-T2 = __ Ohms?
T1-T3 = __ Ohms?
T1-T4 = __ Ohms?
T2-T3 = __ Ohms?
T2-T4 = __ Ohms?
T3-T4 = __ Ohms?

That is 6 possible pair combinations, and only 2 of the 6 should give you a small resistance reading, while 4 of the pairs should read open circuit. At this point you will have identified 2 pairs of wires, and one pair will be for the run winding, and the other pair will be for the start winding. The pair with the smaller resistance is probably the run winding.

However, If you only get a resistance reading for 1 pair of the 6, than that pair is probably the run winding. In this case you are not getting a resistance reading for the start winding because the relay is broken or disconnected from the motor. This would also be the case for motors without a relay in it. To get around that problem, you can temporarily short across the 2 terminals of the capacitor with a small jumper wire, and then see if that other pair gives you a resistance reading. If it still doesn't, then there could be a problem with the centrifugal switch, as in, it's open for some reason. But this is only important if you really want to know the resistance of the start winding. Which is not really important.

But to be 100%, mark the pair of wires that gave you the lowest resistance reading, and move them aside. Next, check the two wires you have left and see if one of them is connected to the capacitor or the relay. If that is the case, than that pair is definitely for the start winding.

So now that you have identified the pair for the run winding, and the pair for the start winding, mark the wires with lables. You can use the labels R1, R2, S1, S2 as shown in the pictures above. At this point, you should test this without using a drum switch:

Step 01: Tie R1 and S1 together
Step 02: Tie R2 and S2 together
Step 03: Get a power cord
Step 04: Connect black wire from power cord to R1/S1
Step 05: Connect white wire from the power cord to R2/S2
Step 06: Use electrical tape to insulate the temporary connections you have made
Step 07: Bolt down or clamp down the motor to the bench. If you don't, it might jump or fall of the bench as it spins up
Step 08: Put on safety glasses
Step 09: Step back
Step 10: Plug it in
Step 11: Note the direction the rotor is spinning
Step 12: Unplug it
Step 13: Remove the electrical tape
Step 14: Disconnect all the connections you have made
Step 15: Now you will try to run it in the reverse direction
Step 16: Tie R1 and S2 together
Step 17: Tie R2 and S1 together
Step 18: Connect black wire from power cord to R1/S2
Step 19: Connect white wire from the power cord to R2/S1
Step 20: Use electrical tape to insulate the temporary connections you have made
Step 21: Step back
Step 22: Plug it in
Step 23: Note the direction the rotor is spinning. It should be the opposite direction than before.
Step 24: Unplug it.
Step 25: Remove electrical tape:
Step 26: Disconnect all the connections you have made
Step 27: Drink a beer

At this point, set the motor aside, and focus on the drum switch. To start, take the cover off the drum switch, and take pictures of it for all 3 positions: forward, off, reverse. Post the pictures here and once we know the internal connections of your drum switch, we can figure out which way to connect the motor.

Cheers
 
Also, looking at Paula's schematic, if GE used standard labels for their wires, I'm guessing that T1 & T3 are for the run winding, while T2 & T4 are for the start winding.
 
thanks; I'm reading this now. Last night, a helpful forum member and I chatted. He's going to talk me through the steps using the meter, etc. But I'm reviewing iron junkie's info right now.

I'm thinking the capacitor can wait and just do the wiring right now (one thing at a time). If the motor goes bad later, I can then check to see if the cap needs replacing and do that procedure.

I purchased 10 ga wire for the plug, which turned out to be too thick so gotta return and get 12 or 14. I believe 14 is minimum you can go with 7.5 A at 115 V. It sure makes fitting all the wiring into those tiny boxes a lot easier. I'm leaving to get the wire in about 3 hours; need about 10 feet to reach the outlet, so if there's any comments on the wiring, let me know before I go please.

btw, step 27 is the best, especially after flipping solder and asbestos in the eyes

Cheers

DaveV
 
Hi Dave,

I ordered a new capacitor for my motor because the old one got flooded with water and had rust on it. I assumed it's bad but never tried it.

The capacitors they use for these motors are aluminum electrolytic capacitors which are non-polarized.

Here are the things to look for when selecting a capacitor, and you should look at the old one to figure out what you need.

1. What voltage is it rated for. Should be somewhere around 110-135V for single phase motor.
2. What the capacitance it has. Mine had a range listed at 430-480 microfarads.
3. The physical dimensions of the capacitor. You need to look at the diameter and length of it. If the diameter is too small, it will probably rattle around in the enclosure it is
mounted in on the motor.

I've found two brands of these caps so far. "Dayton" which is sold by grainger.com, and "Cornell Dubilier" which is sold by mouser.com and digikey.com.

The "Dayton" brand is made in China. The "Cornell Dubilier" capacitors listed on mouser.com indicate they are made in USA. But then again, alot of brands might manufacture capacitors in multiple countries, so they might be chinese too. Don't know.

Here is the datasheet for the "Cornell Dubilier". Look through it to see if you find one that matches, or is close to, the one you already have.

http://www.cde.com/catalogs/PSU.pdf

I should also add that McMaster-Carr has these capacitors too. Not sure what brand they are, and I didn't buy from there because they didn't have the physical size I needed.

http://www.mcmaster.com/#motor-maintenance-controls/
 
As far as the wiring, my motor is rated for 8.0/4.0 amps, depending on the voltage you run. So max is 8.0 amps for 110V. The wire that was there from factory was 16 gauge. If you check cables listed on McMaster-Carr's site, they list 16 gauge wire as being rated for maximum 14 amps.

So 10 gauge is probably overkill for a 7.5amp motor.

16 gauge or 14 gauge is most likely more than enough.

Cheers
 
thanks, iron-junkie, again! I prepared all of the wires: motor, drum, outlet (the 2 wires) with 12 gauge. It fits into the plug and drum MUCH easier than 10 ga!!!! Also, I read somewhere that the starting voltage or amperage or something shoots up really high so the thick wire will provide peace of mind at least.

I placed connectors on the end; in short, I'm ready to hook it up. Kelly, from this forum, has offered to walk me thru it using my electric meter. We were going to do it last night by phone but wife business got in the way so perhaps tonight.

Once it is up and running (hopefully), I will get to the capacitor part. I might order from M-C to save on shipping, since I also need to get gits from them, but will comparison shop. I also need to measure the cap dimensions as Iron-Junkie said.

BTW, when I took the bolts off the cap, there was swarf under the mounting; how in the heck did swarf get all the way back and inside there is BEYOND ME?!

I know now why Steve W's book doesn't even touch wires, switches, caps, relays and motors: there are too many dang varieties and vagarities to them!

Once this is all done, I'll be sure to post photos and a story to go with them
 
lathe rewired - YouTube

Thanks all, esp. Kelly, who walked me thru resistance test last night; and iron junkie

all wiring 12 gauge; sorry for safety violation (removed drum switch cover), won't do in future but done testing; goes forward to reverse thru neutral without damage, even when running; having trouble fitting all the caps in the motor box (wires twisted inside caps and covered with tape); also need to replace the capacitor, but right now I need to put the headstock and countershaft back together again.

All the old and frayed asbestos wire is in the trash. Hopefully it doesn't pollute some landfill site too much

oh, the colorful diagram I drew and the black and white schematic that I posted were accurate should someone else have identical motor, relay, drum switch, which is highly unlikely and if they did it would probably be impossible to find this post once it's buried over time

Cheers
DaveV
 
Nice to see you got it working. Good work. :)

But I still think the 12 gauge wire is overkill. Did you by any chance measure the diameter of the wires inside the motor?
 








 
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