Sciencemadness Discussion Board

Identifying wires of an old electric motor

Endimion17 - 21-7-2013 at 07:43

So I've got this old motor from a washing machine, made in 1983 and I have absolutely no idea how to connect it to the mains. I want high rotational speeds, just like in washing machines.
I've got a long cable with two wires ready. No ground wire, though.

There are 6 wires at one plastic junction of the casing.
blue, red
yellow, brown

It's an asynchronous monophase electric motor intended for 220 V @ 50 Hz.

So, what to do? I've tried several combinations and turning it on for like 0.1 s to avoid damage, and all I've got were buzzing sounds, one time somewhat louder. The rotor is not moving, although it's not corroded or anything.
If you need me to check something with a multimeter, I've got one.

As much as I know about chemistry, I know very little about electrical engineering (OK, I'm a walking disaster) so please help me of watch me get killed by electricity. :)

Antiswat - 21-7-2013 at 08:38

rubber gloves first of all when playing around with stuff you dont know shit about (like me)
on a computer power supply black and red means 12V 5A
perhaps connect the wires to your multimeter in different combinations and measure currents?
supposing the wires that have equal amount would be the ones fitting together
dont take any of this for truth, i know just a tiny bit more electrical than organic chemistry

bfesser - 21-7-2013 at 08:46

Do you have the start/run capacitor? Please post a photo of the data plate. (Also, try Google.)

[Edited on 7/21/13 by bfesser]

froot - 21-7-2013 at 08:55

Usually these motors are wired for 2 speeds and bi-directional rotation. If you still have access to the rest of the machine look for a capacitor that's connected through that plug to the motor, you will need it to get the motor turning. All asynchronous single phase motors need a capacitor to generate the rotating field. If you don't have the capacitor a local electrical outlet will be able to assist you if you show them the motor. The value of the cap is important for performance but if its as much as 50% out of spec it will still turn.
Connecting is simple, take 3 of the wires with the most similar resistance between each other, connect the capacitor across 2 of them, and your supply to the remaining wire and one of the terminals of the capacitor. If you want to reverse the motor simply move the supply from the one cap terminal to the other. Just be sure none of the wires are grounded to the motor casing.

Edit... If the motor appears to turn too slowly, this could be the slow speed configuration, just move your connection to the other 3 wires.

[Edited on 21-7-2013 by froot]

watson.fawkes - 21-7-2013 at 10:14

Quote: Originally posted by Endimion17  
There are 6 wires at one plastic junction of the casing.
There are fifteen pairs of DC resistance given 6 terminals. Get out your ohmmeter and measure them all. Post back here with the results. Also, one of the terminals is likely connected to the metal body frame of the motor; figure out which one this is as well.

I'm assuming there's no start/run capacitor connected.

bfesser - 21-7-2013 at 10:22

If you just tell us the washing machine model or the motor model, someone could look it up in a service manual. Washing machines are designed to be serviced, there are no secrets. This should be trivial.
Quote: Originally posted by Endimion17  
There are 6 wires at one plastic junction of the casing.
blue, red
yellow, brown
Unless I've forgotten how to count, that's only 5 leads. I've never seen a 5 lead washer motor before. Is the sixth lead black?

Also, <em>every</em> washing machine I've serviced had a <a href="" target="_blank">wiring diagram</a> <img src="../scipics/_ext.png" /> attached to it on the back or inside somewhere, usually in a plastic sleeve.

By the way, I don't mean to be rude, just straight to the point. I feel your <a href="viewthread.php?tid=17008">pain</a>.

[Edited on 7/21/13 by bfesser]

jock88 - 21-7-2013 at 14:35

Quote: Originally posted by Antiswat  

on a computer power supply black and red means 12V 5A

No, it does not.
Has the motor any brushes?

[Edited on 21-7-2013 by jock88]

IrC - 21-7-2013 at 15:40

Endimion17 - 21-7-2013 at 17:29

I'll take a photo of the motor wires and any details tomorrow.

Yes, I presumed it needs a capacitator to start the spinning cycle, and that's kind of bringing me down because I've got a huge pile of crap taken from perhaps two washing machines and finding the exact capacitator will be a challenge. Imagine taking a washing machine and just gutting the shit out of it. There's like a third of cubic metre of wires and other crap.
Indeed, there are 5 wires, my mistake.

Everything I know about this motor is on this little paper that has been glued to it.

I'll see tomorrow if I can find any more details, but I really think there aren't any.
Could it be that the capacitators are somewhere inside? :/
I see no brushes. Washing machine motors shouldn't have any. They're designed to be really durable and to spin for at least ten years without repairing. I don't know, but it seems that at high speeds, the brushes would be gone in a month or two...

Finding any diagrams for this ancient thing would be a needle in a hay or worse. I've searched for it online and I've only got one proper hit - there's some guy selling the exact motor. :D

And to think I was actually considering this will be a piece of cake. I really thought I'll just have to connect it and have it spinning like crazy.
Don't worry about me getting zapped. Whenever I touch it, I always completely disconnect it from the mains, and the thing is resting on a dry wooden block.
I know a lot about safety because it's something you know if you understand the physics behind electricity , but when it comes to electrical engineering, I'm pretty much an ignorant.

I like that video. I've hoped it would be that simple.

[Edited on 22-7-2013 by Endimion17]

bfesser - 21-7-2013 at 18:01

<em>Imagine</em> taking a washing machine apart? I've done that&hellip; many times. It's fun! Gutting household appliances is one of my favorite things to do, and it's quite educational.

The capacitor should be very easy to find, and will be marked 16 &micro;F (sometimes "mfd"). The capacitor won't be internal; they're external so they can be easily replaced. The cap should look similar to one of the pictures below (or a variation thereof), and I wouldn't expect the washer to have more than one cap. As a bonus, motor start/run caps are dirt cheap and available all over the place.

<img src="" height="100" /><img src="" height="100" /><img src="" height="100" /><img src="" height="100" /> <img src="" height="100" /><img src="" height="100" /><img src="" height="100" />

You don't need a diagram for the motor, if anything you need the wiring diagram for the washing machine.

<hr width="800" />
While we're on the topic of destroying washing machines, here share a few YouTube videos I enjoy. <a href="" target="_blank">Washing Machine Self Destructs</a> <img src="../scipics/_yt.png" /> from one of my <a href="" target="_blank">favorite</a> <img src="../scipics/_yt.png" /> YouTubers. And I honestly don't know <a href="" target="_blank">what's going on</a> <img src="../scipics/_yt.png" /> in this one, but I like it!

[Edited on 7/22/13 by bfesser]

Xenoid - 21-7-2013 at 18:01

Quote: Originally posted by Endimion17  
...finding the exact capacitator will be a challenge...

Why? The label clearly says the capacitor is 16uF / 500V

Endimion17 - 21-7-2013 at 18:11

I like gutting appliances, too. I actually salvage interesting capacitators and other neat stuff whenever I come across something defunct.
But the reason this will be a difficult task is because the parts are covered in thick, damp dusty delight. God knows what's inside. I can barely see some wire colours - it's that bad.
Reading capacitator information will take some time.

Couple of years ago my father decided he wanted to destroy a vintage washing machine that was probably functional, and to mix those guts with other electrical crap laying around. Now it's just a huge pile of undiferentiated electrician's protoplasmic dream, covered in goo.

[Edited on 22-7-2013 by Endimion17]

Endimion17 - 21-7-2013 at 18:36

About that washing machine destruction, that's arguably one of the best things uploaded to YouTube, ever.
I love the remixed video, with googly eyes.
<iframe sandbox width="420" height="315" src="//" frameborder="0" allowfullscreen></iframe>

I've nearly pissed my pants the first time I saw it. :D

Antiswat - 22-7-2013 at 05:55

Quote: Originally posted by jock88  
Quote: Originally posted by Antiswat  

on a computer power supply black and red means 12V 5A

No, it does not.
Has the motor any brushes?

[Edited on 21-7-2013 by jock88]

well, 5 is an estimation, theyre said to run very stable, the stream of H2 before i ruined it seemed to be pretty well around 5A if not more, didnt increase or anything alike
on the sticker it says
-12V +5Vsb
0.8A 2.5A
9.6W 12.5W
again.. it wasnt 2.5A and it wasnt 0.1A, so by that i suppose it could have been 5.5A
any other amperages written is 30A in which it certainly was not
also all of these computer power supplys are widely different, as in there different types, not sure how many exactly but it always varies a tiny bit from brand to brand

Endimion17 - 22-7-2013 at 06:30

I've cleaned the motor from the layers of dust and spider web and smeared lots of WD-40 all over it (didn't want to spray it as it might get inside and dissolve something), and put some lithium grease in the bearings. Other than the ugly lacquer and some surface rust, it looks fine, doesn't seem to have any serious issues.
The last time it was in the washing machine, it was working without problems. It was not stored in a humid environment. Close inspection of the copper wiring shows no lacquer deterioration.
photo1, photo2

Now I'm off to measure resistances between the terminals.

I think the brown and the blue wire might be the live and the neutral wire, respectively. Those are the usual colours used here.
Yellow might be the ground wire (it's yellow-green that's used today), and the red and white ones might be for changing the rpm.

[Edited on 22-7-2013 by Endimion17]

Endimion17 - 22-7-2013 at 07:41

OK, 5 wires, 10 combinations without repetition.

white-blue 14.2 Ω
white-red 29.1 Ω
white-yellow 70.0 Ω
white-brown 69.0 Ω
blue-red 43.0 Ω
blue-yellow 83.5 Ω
blue-brown 82.6 Ω
red-yellow 98.1 Ω
red-brown 97.1 Ω
yellow-brown 77.3 Ω

Keep in mind I've used one of those shitty digital multimeters.

I've also tested the resistance between each wire and one of the exposed screws and the multimeter shows infinite resistance, indicated by the typical "1" error display.
I expected low values, perhaps less than 1 Ω. After all, one of the wires should've been the ground wire, directly connected to the casing.
Am I doing something wrong here? I've cloesly inspected the wires inside the casing by looking through the holes - all of them are tied together and seem to supply the windings. Nothing seems to be connected to the casing. Is the motor supposed to be grounded by the actual contact between the casing and the washing machine, which is grounded already?

I'm off to search for those crapped capacitators.

edit: Found the bastard.
While I wait for futher instructions, I'll prepare some wires and clean the contacts.
If you give me bad instructions so I get electrocuted, and if I turn into a ghost that can interact with you, I'll find you and be a real pain in the ass for the rest of your life. :D

[Edited on 22-7-2013 by Endimion17]

bfesser - 22-7-2013 at 09:22

It's likely, given the age of the machine, that the motor was simply grounded to the metal chassis through the mounting tabs. For safety, and due to the advanced corrosion of the housing, I would recommend carefully drilling and tapping a hole in a safe place on the housing, and screwing a terminated grounding wire to it. Ideally, you would put in a 'toothy' lock washer that will bite through oxide layers to get really good electrical contact between the crimp terminal and the housing. This would also help to prevent the connection from loosening by mechanical vibration. I've included a photo of the grounding wire I put on my vacuum pump and some other relevant photos.

<table cellpadding="0" cellspacing="4"><tr><td><img src="" height="175" /></td><td>vac_pump_ground.png - 86kB</td></tr><tr><td align="center">internet example</td><td align="center">my pump's ground</td></tr></table>

<table cellpadding="0" cellspacing="0"><tr><td><img src="" height="100" /></td><td><img src="" height="100" /></td><td><img src="" height="100" /></td><td><img src="" height="100" /></td><td><img src="" height="100" /></td></tr><tr><td align="center">grounding screws</td><td align="center">crimp terminals</td><td align="center">good</td><td align="center">better</td><td align="center">best</td></tr></table>

If you use the pictured type of grounding screw, only put a washer between the terminal and the housing, as the screw has it's own teeth. Use the pictured type of terminal on any ground (they can't accidentally slip out or be easily removed), but choose the appropriate size for your wire gauge (color coded) and post. Use either a bare copper wire, or an insulated green wire to avoid confusion (yellow/green stripe is acceptable).

[Edited on 7/22/13 by bfesser]

watson.fawkes - 22-7-2013 at 10:28

Quote: Originally posted by Endimion17  
white-blue 14.2 Ω
white-red 29.1 Ω
white-yellow 70.0 Ω
white-brown 69.0 Ω
blue-red 43.0 Ω
blue-yellow 83.5 Ω
blue-brown 82.6 Ω
red-yellow 98.1 Ω
red-brown 97.1 Ω
yellow-brown 77.3 Ω
White appears to the neutral wire here. Note that for both red and blue wires, all the resistances "go through" the white terminal, that is, the resistance, say, red-yellow is the sum of the red-white and white-yellow resistances (to within an ohm). So that's three down.

The yellow and brown terminals, however, are wired differently. Note that the resistances on all three legs are with 10% of each other. That seems to speak to a three phase delta motor. The run capacitor is used to shift the phases around that they're adequately separated. The capacitance is specified on the motor so that the phase shift is correct for the inductance of its drive coils.

The next step is look up some schematic diagrams for other motors. You don't need to get the exact model, just one of the same basic design. My guess is that the red and blue wires go to the start windings, and that you'll find a centrifugal switch somewhere (as you've described it, in a box of parts) that disconnects the start windings once the motor comes up to speed. You'll definitely find such a switch in the schematics.

papaya - 22-7-2013 at 12:10

"ASINHRONI MONOFAZNI MOTOR" means asynchronous mono-phase motor!

Endimion17 - 22-7-2013 at 13:01

bfesser, I've cleaned one mounting tab with an emery paper and connected the terminals to a cable and made a good contact between the casing and the ground wire. photo

The resistance between the casing and the cable end is 0.2 Ω so I guess I did a good job.

Just to add some insulating tape and I'm done. Now it's basically ready for experimenting. It's been a while since I've been soldering wires and my old soldering gun is heavy piece of crap so it's taking some time.

watson.fawkes, I've noticed the regularities between the numbers, but that was it.
Unfortunatelly, I don't know enough about these things to understand the difference between an monophase asynchronic and three phase delta motor.

The problem is - I'm not sure how this centrifugal switch looks like. I see there are many designs. Is there something all of them have? A spring, maybe? I'm not even sure there is one, there seems to be only a pile of potentiometers and cables. There is also a water pump, but seems to be in a terrible condition.

Does this help? There are lots of schematics...

BTW thank you all for helping me. :)

[Edited on 22-7-2013 by Endimion17]

bfesser - 22-7-2013 at 13:20

Soldering isn't ideal, but I'm guessing you don't have the tools to do crimped butt splices or terminals. I've tried the crimp-less butt splice pictured below, and it's not bad. The second type pictured I absolutely hate. And sometimes Wire-Nuts&reg; (twist-on connectors) are better than soldering, but your joints look alright.
<table><tr><td><img src="" height="120" /></td><td><img src="" height="120" /></td><td><img src=" ire-nuts.jpg" height="120" /></td><td><img src="" height="120" /></td></tr><tr><td align="center">not bad</td><td align="center">hate 'em</td><td align="center">ol' standby</td><td><a href="" target="_blank">NASA spec.</a> <img src="../scipics/_pdf.png" /></td></tr></table>
How about a few pictures of the piles of junk? Perhaps we can just point out what you need.

[Edited on 7/22/13 by bfesser]

Endimion17 - 22-7-2013 at 13:37

I've got nothing of that kind at home. Soldering is ok, it's rigid. I used flux, so the wires were dripping wet with solder alloy. They're interlocked now.

I'll post a few photos of some "devices" from the pile of cables tommorow as it's almost midnight right now, and the stuff is outside my apartment. I think there are just some potentiometers and pumps.

Magpie - 22-7-2013 at 13:55

Quote: Originally posted by Endimion17  

watson.fawkes, I've noticed the regularities between the numbers, but that was it.
Unfortunatelly, I don't know enough about these things to understand the difference between an monophase asynchronic and three phase delta motor.

3-phase power is normally only used for heavy duty, like industrial or agricultural applications. If this is a motor from a domestic washing machine I would surely think it is monophase.

Also, papaya then confirmed this by reading the nameplate. ;)

Endimion17 - 22-7-2013 at 14:32

While I understand the differences between the basic motors (it's something we've been learning in highschool physics), and what phases do, design variations like "three phase delta" elude me.

There are lots of different designs made for particular purposes, but my understanding is pretty much basic.
It's like cars. I know the concepts, I can explain two-stroke, four-stroke internal combustion engines, spark plugs, cam shafts, chemistry of the whole process, etc., but I can't really fix an older type car.

If I don't find an easy solution to this soon, I'll probably just let it go. It's not worth the hassle.

ElectroWin - 22-7-2013 at 14:55

i have a split-phase motor at home, that has just two phases, 90 degrees apart. but there are only 3 wires. i noticed, though, when i energize the pairs, the shaft turns a little, so it was possible to discover the phase relationships.

maybe you can do the same?

Endimion17 - 22-7-2013 at 15:17

I've tried to apply the 220 V on 10 combinations (nothing happened, just buzzing), but I have 10 more if I reverse the wires going from the mains so I'll try that tomorrow.

Judging by the similar problems people experience with these motors, it seems that two leads have to be bridged by the capacitator, and the neutral and live wire go to other two wires. The fifth wire can be left alone.
There are two speeds and that's it.

I'll just have to make a bunch of combinations and hope for the best. I have a magnetic circuit breaker in my house so if I make a mess, it will trip. I doubt that extremely short powering up will do any damage.

watson.fawkes - 22-7-2013 at 16:31

Quote: Originally posted by Endimion17  
I don't know enough about these things to understand the difference between an monophase asynchronic and three phase delta motor.
The nameplate designates the external power supply. What I was talking about given the resistances is the internal wiring of the motor. With split-phase supply, you can generate a third phase by shifting one of the two legs 90&deg; with a capacitor. You don't get the same 120&deg; symmetric three phase, you get an asymmetric kind. An appropriate schematic appears on this page, which has a lot of motor information generally. The three-phase schematic is wye, not delta, to be sure.

When you try energize an induction motor without its starter circuit, you may have to manually turn the shaft on it to get it to start turning. This is most safely done by turning the shaft to spin up the rotor a little and then immediately energizing the circuit. You can also do it after energizing it. In either cases wear leather gloves.

The centrifugal cut-out switches, if present, are likely on the inside of the motor. It's also possible that the mechanical timer in the washer simply left the starter coils engaged for one tick.

ElectroWin - 22-7-2013 at 16:32

AC pulse leads to buzzing, yes. dont do that.
reversing polarity will make the shaft turn the opposite way, but unless you involve all the phases, it will just buzz.

i used a DC pulse so i could tell polarity. but 220V is too high i expect (it may be too dangerous). maybe try less than 50V pulse

[Edited on 2013-7-23 by ElectroWin]

IrC - 22-7-2013 at 17:20

"Capacitor start, induction run motors often have dual-voltage ratings of 115 volts and 230 volts. The connections for a capacitor start motor are the same as those for split-phase induction motors"

elec4_22-8.jpg - 35kB

elec4_22-10.jpg - 29kB

Magpie - 22-7-2013 at 19:25

IrC, that looks like a wiring diagram for a US motor, where it can be powered at 120VAC or 240VAC. In the case of 120VAC you have two wires, black (hot, 120VAC) and white (neutral, 0 volts).

Then for US use of 240VAC you don't have a neutral but instead two hot wires at 120VAC, 180 degrees out of phase. That's my understanding. If I am incorrect, please correct me.

As Endy is in Europe and the name plate seems to be in Italian (?) I assume this is a motor of Euopean manufacture. I believe in Europe they have a hot wire at 220VAC and a neutral at 0 volts. Again, please correct me if I am wrong.

So that wiring harness should somehow be compatible with normal European domestic electrical power supply.

[Edited on 23-7-2013 by Magpie]

IrC - 22-7-2013 at 20:59

While there are differences between EU 'universal' motors (vid I previously posted) and US motors, the theory of induction motors is what it is no matter where you are. The above post is a guide for typical wiring the circuit and placement of the starting capacitor since from the plate clearly the motor uses one. If the motor takes off with no load it could possibly operate fine without it. A high torque load on the shaft at initial starting must be overcome with the start capacitor circuit functioning. The amount of that load (force needed to start rotation) determines the capacitance in uF required for rotation to commence.

In any case when you are sitting with a group of wires and a DVM trying to determine how it should be wired, looking at schematics of various typical configurations helps in making sense of the resistance readings. Start windings will have a lower impedance than run windings, so this helps separate wire pairs as to likely function. Or at least gives you some starting points. Knowing the start winding goes in series with the capacitor and the centrifugal switch with this circuit in parallel with the run winding can be understood by looking at the diagrams. Handy to know when determining the wiring of the motor in question in this thread. There is no set rule that older 1/2 HP single phase motors in the EU are not in principle similar in design to the old Maytag here. Whether 50 HZ or 60 HZ merely determines the proper winding impedance's for the line frequency. In short the theory works there as it does here. In some designs the start winding takes itself out of the circuit as the rotor RPM increases due to counter EMF. The problem with this design is that it cannot overcome much of a starting load. Add a transmission and a big rotating tub to the starting load and you really need the higher starting torque possible in the capacitor start design. This is the reason this motor type has always been so common for washing machines and dryers.

froot - 22-7-2013 at 23:55

Ok try this....

Connect one lead from your supply to the blue.
Your capacitor from the blue to the red.
The other supply lead to yellow, brown or white depending on the speed you want. My assumption at this stage is that you can forward/reverse the motor with the yellow or brown.

Edit to explain myself here, sorry.

Red - white is the phase shift winding.
Blue - white is the high speed winding.
Yellow/brown - white are the slow speed forward/reverse windings respectively.
Like Watson said the reading between yellow and brown is peculiar and implies a 174 ohm winding between them. This might be a fault in the motor so if the low rpm connections do not work I'd write it off to that, probably why the machine was put out to pasture.

[Edited on 23-7-2013 by froot]

[Edited on 23-7-2013 by froot]

[Edited on 23-7-2013 by froot]

Endimion17 - 23-7-2013 at 02:44

Yes, this is 220 V, Yugoslavian made. Teslaland. :P

I've listened to watson.fawkes's advice with the initial turning and yes - it works (thanks!), but I initially forgot the combination for the maximum speed.
There are lots of combinations for low speed.
Anyway, for high speed, one wire goes to the white terminal, and the other goes to the blue terminal. Froot was right.

The motor turns in any direction previously introduced. As long as it's turning, it will pick up on speed when plugged in.
The maximum speed made it spit some dust balls out of the casing, but it works rather quietly, if you don't count the sound of air. It's like a really powerful fan. Sometimes, depending on its position, something seems to be touching inside. It's like a grinding sound, but only when you power it down and it's close to a complete halt. I think the rotor is a bit distorted, but the whole motor doesn't vibrate at all, so it's ok. The washing machine was probably dismantled because of the problems with the water pump system.

I think it might have a centrifugal switch after all, because when it picks up speed, I can see the white fan moving one step in.

Without capacitor, it takes almost 3.5 s for full speed. It takes 24 seconds to a complete halt after powering down.
I've been experimenting with it for the past hour and it was pleasantly warm. If it works 1 min at high speed, it gets quite warm, seems like ~50 °C. After 5 minutes, I can't really hold my palms on the casing for more than few seconds. It might be close to 60 °C. Is that ok?

I've also tried froot's advice with the capacitor. It works, but only with high speed. It does not kickstart when I try his advice with yellow or brown combination or some other combinations for low speeds, but it doesn't really matter as I need high speed only (I might turn this into a homemade lathe one day).
With capacitor, it jumps to high speed in less than a second. No wonder those old machines used to jump up and down like crazy. :cool:
It also runs a bit faster when connected to a capacitator.

Thank you all for the help, it really sped things up. If someone wants me to do some other combinations, let me know.

Oh, I've never used any gloves, but I was keeping my eye on the main switch. Everytime I touch something, it's off.

One more question - how fast are capacitors such as these supposed to discharge? I've been measuring the voltage across its terminals and it falls down rapidly, at an exponential rate. It takes around a minute to reach 0 V. I think that's too fast. Something might be wrong with it.
If I measure AC voltage while the motor is working, it reads approx. 450 V across the terminals but goes up and down few volts.

[Edited on 23-7-2013 by Endimion17]

froot - 23-7-2013 at 03:23

The cap seems fine considering the improvement in performance when you connect it. Does it overheat when the cap is connected? A simple check for the cap is when fully discharged (by shorting it) measure resistance in ohms across the terminals. The resistance should increase exponentially over a short time to open cct.

Endimion17 - 23-7-2013 at 03:39

I haven't noticed any overheating at all.
My multimeter shows "1" error (infinite) when measuring its resistance in ohms. No reaction whatsoever.

edit: It's ok now. I think it takes more than just a short touch to discharge its plates. After shorting it for few seconds, multimeter shows an exponential buildup of resistance. It quickly jumps up from few kΩ to 2000, the limit of this device.

[Edited on 23-7-2013 by Endimion17]

IrC - 23-7-2013 at 06:29

Sounds like the start circuit is wired wrong if it has little or no starting torque, especially if you have to initially turn the shaft. Unless froot is right and the motor is defective, always a possibility *. Since it is AC the capacitor's charge will depend upon where in the cycle it is when power disconnects. Meaning expect little voltage on the capacitor most of the time after you shut the power off. I should add: and how you have wired the circuit.

* A handy way to find out is the use of a growler:

[Edited on 7-23-2013 by IrC]

jock88 - 23-7-2013 at 14:20

Most washing machine motors have brushes where I come from. But some don't.

@AntiSwat. Look up the wires for a computer power supply. Red is 5V. Black is earth. Yellow is 12V..............

Endimion17 - 24-7-2013 at 01:18

Here's an interesting observation.
I've placed an ammeter between the phase wire and the motor. When I turn it on, it jumps above 30 A, then stays at 30 until it gains speed, and afterwards falls to 23 A. I think it's because of that centrifugal switch inside.

It's cool how the power of this motor at full speed is merely 74 W, yet its torque and the speeds are much greater than the ones of a 130 W hand mixer, which has a synchronous motor with commutators.
By the way, jock88, washing machines with brushes? Isn't that kind of unusual? Which country is that, if I may know?

froot - 24-7-2013 at 02:06

If you're drawing 23A at no load there's a problem, for 74W you should be drawing around 3A?

The hand mixer's brushed synchronous motor will at much higher speeds where torque is traded in to achieve this. Incidentally you can run those synchronous motors using DC too, try 12V DC and see how it performs.

Mildronate - 24-7-2013 at 02:56

you can drive it without capacitor you can use button or turn with your hand it (actually i don know how to correctly tell in English :D).

[Edited on 24-7-2013 by Mildronate]

IrC - 24-7-2013 at 07:22

Quote: Originally posted by froot  
If you're drawing 23A at no load there's a problem, for 74W you should be drawing around 3A?

The hand mixer's brushed synchronous motor will at much higher speeds where torque is traded in to achieve this. Incidentally you can run those synchronous motors using DC too, try 12V DC and see how it performs.

I agree with froot. Sounds like the motor may have at least two turns shorted from melted enamel or wear. Not enough load to stop it from turning but enough to make it pull excessive current and run hotter than normal. If so this will eventually get worse as heat shorts even more turns. Either that or it is still wired wrong, say still running on a start winding as one possibility.

watson.fawkes - 24-7-2013 at 07:34

Quote: Originally posted by IrC  
Either that or it is still wired wrong, say still running on a start winding as one possibility.
This is what I suspect. Start winding generally have lower resistances than the main run windings. My guess is that the run capacitor goes across the yellow-brown pair, and than the power goes onto either yellow or brown, each of which will cause the motor to turn in a different direction. So if trying this, and it doesn't start up itself, be sure to try giving the rotor its initial momentum in each direction.

I'd also have to guess that there was a second start capacitor that went one only one of the other two low resistance windings. You'd need to measure the inductance of the start windings to determine its optimal value.