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Electric motor wiring.

Luka's picture

I have a real old electric motor that I would like to try out.

This thing is huge. Motors built nowadays this size are 5 HP and up.

I am attaching a pic. For dimensions purposes, the body of the motor between the two end plates is 7 inches. Overall diameter is probably 7 or 8 inches.

On the plate is this information...

~~~

wagner electric corporation
354
st louis usa
Alternating current motor type KA
frame 75
model W30 B185 k354
3/4 hp
1725 rpm
1 ph 60 cycles
110v 10.4 amps
220v 5.2 amps
cont rating 40c ser number n81

~~~

It is the motor off an old air compressor. I'd like to get that compressor working. I have to get this motor working first.

I am not sure whether it was wired for 220 or for 110. More than that, I am not sure of the wiring in any way.

There used to be a box on the side, where the wires went in. But that box was torn off long before I got it. (Not removed... TORN off.) The wires are just cut off right at the motor.

I want to wire it for 110v.

Does anyone know anything about the wiring on this thing ?

Before you say anything... there is no wiring diagram plate anywhere on this motor. I would assume that was on the box that got torn off the side of it.

I am going to have to remove the back plate of the notor itself just to get to any wires inside. It still spins by hand so I have hope for it...

I bet before you know it, babies will be sent home with a sticker warning them that living causes death~piffin '06

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It's a small world. Until you have to walk home...

(post #73989, reply #1 of 59)

How many wires? The thing is one phase AC, which says it's an induction motor, probably capacitor start. Is there a capacitor, or a place where one was once mounted?

The run windings would generally be two windings -- four wires -- that can either be wired in series (240V) or parallel (120V). That's fairly simple. But how the start windings (if any) are wired up is an entirely different issue. And then there's the centrifugal start switch, if any. (Some units this size might use a motor starter that uses a timer or current sensor instead of the start switch.)


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #73989, reply #2 of 59)

usually if you have two wire out of motor, 110 one be hot the other netrual, for 220 both be hot and case be ground. It really does matter on 110 which wire, that will determine which way the motor turns.

(post #73989, reply #3 of 59)

Currently it is still sitting on the heater and drying out. (And disgorging all it's spiders and other critters into my kitchen.)

I have seen no capacitor. Maybe there was an external capacitor on the compressor at one time ???

From what I can see from where it is sitting, (Very big, very heavy, and not in a place where it can be moved around right now.), there are 4 cloth covered wires coming out of the casing. Those 4 wires are divided into two pairs, and each pair is connected to one added wire, and taped. So power goes to two added wires which feed the two pairs of wires. I would assume the case is the ground.

Centrifical start switch would be inside the motor, if there is one at all.

I'll be taking this out to the shop later today, like after noon or so. I want to be positive the thing is completely dry. I'll take off the end plate and have a look inside. I'll know more after that.

I am figuring that at the least, I am going to have to get inside and insulate those cloth covered wires better.

When it comes to the capacitor... Isn't there basically one capacitor for all 110v motors ? Couldn't I use the capacitor from an old dayton, and mount it externally ?

As for a motor starter, wouldn't there have to be a double pulley on this motor if it used another motor to start with ? It only has a single pulley.

I'd hate to see this motor wasted. At the size and weight it is, and being only 3/4 hp... I have to figure it's got tremendous torque.

I just found my old dayton motors "cowen paper". A PDF file with generic info on motors. Time to do some reading again.

You know, the one good thing about having such a crappy memory is that after a couple years or so, movies become "new" again to me. And some books, too. But it sure is irritating that I have to re-educate myself on this kind of stuff every time I have to do something again.

I bet before you know it, babies will be sent home with a sticker warning them that living causes death~piffin '06

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It's a small world. Until you have to walk home...

(post #73989, reply #4 of 59)

Hate to ask the obvious Luka... but as it's an old beast, have you checked the windings before you invest all this work?


PaulB

(post #73989, reply #6 of 59)

I haven't actually done anything at all with it yet except sit it on the heater to dry out.

When I take it out to the shop and remove the back of it, I'll check the windings while I am checking everything else.

=0)

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #8 of 59)

> Those 4 wires are divided into two pairs, and each pair is connected to one added wire, and taped.

That sounds like a typical 120V wiring. One of the added wires is hot, the other neutral (doesn't make a lot of difference, though if one side seems to be more like black and the other more like white, make the black side hot). The starter arrangement is unclear, but there's a slight chance this is a shaded pole motor or has the capacitor internal.

Do double-check for signs of other wires from other openings, though.

The case should be grounded (especially in a motor of suspect integrity), but the ground should not carry any current. You should probably ohm out between the winding connections and ground, and not attempt to use the motor unless you read at least about a thousand ohms.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #73989, reply #10 of 59)

Thanks again, Dan.

I can't get to this till later. But if I get any grounding at all between either wire and the case, (using the ohmmeter.), I am not going to even consider hooking it up to electricity until I have had a thorough look inside.

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #11 of 59)

Cloth-covered wires, uncertain wiring approach, how to start, WET!, possible internal shorts (now or just waiting until your turn your back!), old varnish on windings...

Luka, I'd junk it. 3/4 horse from Grainger is cheap! And just because its big doesn't mean its got more torque. The HP is stated, and given a fixed RPM (1800 or 3600, 1800 far more likely), the potential output
torque is fixed, too!

They just used to build 'em bigger back then!

Either way, let us know, will you? I love these stories!

Brooks

And a late thought: If you do decide to try it, and/or use it, make
SURE its tightly grounded! We'd miss you...


Edited 9/22/2006 2:58 pm ET by Brooks

(post #73989, reply #13 of 59)

It's the challenge of the thing, more than anything. If I JUST wanted any old motor on there, I'd find another.

=0)

I don't like the cloth covered wires, and will probably try to shrink tube them. Or de-solder/remove them and solder in some silicone covered wires.

It is bone dry now, and I will check twelve ways to sunday to be sure there are no shorts anywhere.

Cheap is in the eye of the beholder. 30 dollars might as well be 3 thousand for all I could scrape together right now. 80 to 300 dollars... forget it.

RPM is 1725 rpm. (It's in the little blurb in my first post, from the metal identification plate.) ;o)

Even as a challenge to myself, I will not go way overboard with this. I am certainly not going to invest in any parts on a hunch. The motor just wouldn't be worth it. But I do like the challenge of learning about it, checking it out, and possibly getting it to run.

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #12 of 59)

Late thought, but with no capacitor the motor is probably split phase and wont have the starting torque for a compressor.


I've a spare 100 HP 460 Vac 3 phase motor in one of the sheds <G>

(post #73989, reply #14 of 59)

It is the motor that was on the compressor, from the factory.

If it has a capacitor, it is internal, or it was separate. I have no idea whether it had or has either of those. Just one of the things I need to figure out.

Since it came from the factory, installed on the compressor, then capacitor or no, it has to have the needed torque. I just have to figure out whether it is supposed to have a capacitor or not.

I was kind of hoping there was an old motor officionado around... ;o)

Oh yeah, I'll be right over to pick up that 3 phase motor! LOL What the heck would I do with that ? =0) It's probably bigger than the entire compressor.

Cool deal that my 20 gallon propane tank turned out to be 30 gallons, huh ? I'm letting it sit a couple days full of water before I empty it.

I have a hunch that with that much capacity, pretty much any compressor that I hook up to it will work to run my air tools.

What did you think of the pipe-fitting/manifold idea ?

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #16 of 59)

It just occured to me that it is going to be a batch getting the water back out of that tank. No vent, of course.

Probably have to get an air compressor hooked up just so I can introduce some air pressure into the tank to blow the water out...

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #19 of 59)

I doubt there is a cap. inside the thing.....more likely just a centrifugal switch....which may need some attention...one quick way to tell is to look at the wires to determine if two of them are a smaller gauge..these are the start winding that is connected THRU the switch

if you can wrap a rope around the shaft and pull start the thing you should hear the switch opening and closing......if you hear nothing then you will have to try a unstick the switch, which of course requires opening the motor up at the end opposite the shaft. if you can open the motor that is....

if the switch is bad and will not work......your testing has reached a conclusion,

either way you can roll the dice and just stick voltage to the leads and see what happens.... single phase motors will always have some part of the windings running on 110 volts and it will try to run if the windings are still intact

I am also curious about one more thing...are there brushes on this Wagner...those were sometimes used by that Mfr.to adjust the motor for the applied voltage.......sometimes.......

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.Wer ist jetzt der Idiot
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(post #73989, reply #20 of 59)

Thanks for the reply !

Ok, you give me better hope here than you know.

Yes, I read about the brushes wagner used to use. I would not be surprised at all to open this one up and find brushes. I am also wondering if, if it has brushes, they are worn too far, and whether I'll be able to find replacements for them. Ah well, we shall see when it is open.

=0)

And open it up, I will. Taking that back plate off, (opposite the shaft), is the very first thing I intend to do. I'm not putting power to it until I check it out that way...

But I am going to get to it a bit later than I had thought. I have to get the old jimmy up in the air right now, to find out what it's gear ratio is. After that I will take the motor over to the shop and take that back cover off.

Using the rope is something I hadn't thought about. I think I'll put a rope on it before I take that back plate off. Then spin it, and listen for the cent switch to open. (No power, of course.) If it doesn't click open, but I do find one in there, I'll know it's gonna have to be fixed.

Also, if I check it out and find no grounded wires or coils, etc, then put power to it and it doesn't start, I'll try the rope while the power is on, to see if it starts and runs.

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #5 of 59)


The bitterness of poor quality remains long after the sweetness of low price is forgotten.

 

(post #73989, reply #7 of 59)

That's a real monster of a drill !

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

.

It's a small world. Until you have to walk home...

(post #73989, reply #9 of 59)

Drill?? I thought it was a Mixmaster.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #73989, reply #15 of 59)

I think it gets something like 60 rpms.



The bitterness of poor quality remains long after the sweetness of low price is forgotten.

 

(post #73989, reply #17 of 59)

So when the bit gets stuck, it whips two guys around 60 times a minute ??

;o)

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

.

It's a small world. Until you have to walk home...

(post #73989, reply #18 of 59)

Heard that that was about it.


Found out in an old thread about it that that was what it was, a coal drill for drilling holes to stick dynamite in.


 


 


be a fwap fwap fwap fwap fwap


The bitterness of poor quality remains long after the sweetness of low price is forgotten.

 

(post #73989, reply #22 of 59)

OK... I see it's time for a little course on motors....

When a motor is rated for more than one voltage, it has more than one set of windings. When you install the motor, for the "high" voltage you wire the two windings in series; for the "low" you hook them up in parallel.

You can identify the winding with a continuity meter; that is, you see which wires are continuous through the motor. This, BTW, is the first test of motor function.

The remaining winding tests are performed with a "megger." This meter allows you to check the condition of the insulation, and will identify shorted or burned out windings. Find an industrial electrician, or power company guy, who knows how to do this.

Single phase motors all have some means to ensure that the motor spins the same way every time. On larger motors, this almost always involves a capacitor... or two... or three. And no, capacitors are not interchangeable, and the size does matter. nor is "bigger" always better.

I suggest you take the thing to a motor shop, and let them have a look.

(post #73989, reply #26 of 59)

I suggest you take the thing to a motor shop, and let them have a look


Don't say that, Jeff'll bring it down here for me to fix <G>


 

(post #73989, reply #28 of 59)

ROFLOL !!

Haaay Aaaaaaaart !!!!

;o)

Next thing up, is to try to pull the other end plate without pulling the armature through in that direction. (And to blow a bunch of that crap out of there as well...)

Be back in a bit.

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

(post #73989, reply #23 of 59)

Ok, here come the pictures.

In this first pic I have removed the end plate, swung it around, and set it next to the motor.

First of all, you can see that quarters are pretty tight in there, even though it is a big motor.

Second, it does have the brushes. Though not like any brushes I have ever seen. They push against the flat front surface there, instead of riding against the outsides of the armature.

Third, no centrifical switch, and no capacitor, either. (I didn't really expect to find a capacitor inside...)

Keep in mind that I have taken this apart without ever even trying to put electricity to it. It didn't make sense to plug it into the juice without first finding out what was inside.

Now, notice that there are no wires going to the brushes. There is a braided wire between two of the brushes, one wire on each side. But there are no wires anywahere that actually come out to the brushes.

There is a square notch in the top of the brush assembly. There is a corresponding tab on the end plate, that slips into that square notch. Is this thing actually using the body of the motor as part of the circuit ???

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

.

It's a small world. Until you have to walk home...

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(post #73989, reply #24 of 59)

In this pic you can see that there is plenty of "brush" left in these holders.

I think I might figure out how to remove those brushes then try to clean up the armature surface a bit. Maybe I'll just leave it alone. LOL

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

.

It's a small world. Until you have to walk home...

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(post #73989, reply #25 of 59)

And in this one you can see that although the wires seem to be pretty much intact, no cracks in the insulation, etc...

They just disappear behind the coil.

If I am going to consider replacing the wires, or even just trying to visually trace them... I am going to have to take off the front plate as well, and try to find a way to pull the coil out.

I may just be SOL about trying to R&R the thing before I put the juice to it.

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

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(post #73989, reply #30 of 59)

That's looking like an "AC/DC" motor. No start switch, no starter winding, no capacitor. The two wires you have should be all you need to deal with.


If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #73989, reply #34 of 59)

It may have a starter winding. (Because it looks like it has a centrifugal switch.) But you are probably right about the rest.

I found what looks like a centrifugal switch.

Yeah, yeah, I figured out the instant I hit the "post" button the last time, that that front plate was not coming off of there without the armature in tow. Because the pulley is on that end.

Anyway, I got it out and I saw what looked like a cent switch. So I cut the pulley off the shaft, and completely removed the front plate. (Yes, I said cut. I don't have a gear puller.)

Here is what I found...

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

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(post #73989, reply #35 of 59)

Ok, the bottom half of the motor was full of a combination of grease and auto body shop dust.

In that last pic you see the thing that may be a cent switch, all covered in grease and bondo dust.

Here, I have cleaned it up.

Now, I don't know if this is a cent switch or not. It LOOKS like those two halves should pivot on the horizontal pins. But I have gently pushed and pried to no effect. Nothing seems to want to move.

If this is a switch, then I have to figure out whether the pieces are supposed to pivot up or down.

You see the "bump" right there in front of you ? It sits on that rod. That rod goes down into the body of the armature.

I am wondering if the two pivoting weights are supposed to swing down toward the body of the armature, and push those rods in.

I have squirted some oil on the big pieces. I'll let it sit for a while, then go try pushing and pulling again. I do not want to really force anything because I might break it.

I may squirt some oil down inside the body of that thing on the bottoms of those "rods". If they end up being able to be pushed down into the body, then that is probably the direction those weights were supposed to go.

If so, I'll take this end of the thing apart by driving out those pins. Then clean everything up, oil it, and put it back together and see if I works.

Now... why would it push those pins in ??? What is at the other ends of those pins ? The "brushes" slide loosely toward and away from the body of the armature, on the other end.

Maybe the weights on the shaft end push those rods in, and the rods push the brushes away from the armature ???

That would make that the start circuit. Soon as it has started, it pushes the brushes away, and the run circuit takes over... ???

But then, that would leave those rods pushing against the brushes the entire time the motor is running. The brushes are held in position by that tab on the body...

If my hunch is correct here, this is probably why they discarded the compressor.

See, there was another reason for these forensics... It helps me to figure out the reason the original owners trashed the compressor. Once I have that figured out then I can figure out whether it is worth it to restore or not.

If they trashed it because of this, then the head is probably still good. Now it becomes worth it to at least check out the head.

=0)

Ok, back to it. Nothing for it but to take those two pins out and see what the "weights" do...

Those will probably be the last pics I take.

I like a good husky woman. Shows they have sandwich making skills ~Gunner '06

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It's a small world. Until you have to walk home...

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