Thanks Matt. My 16yo son took apart an old dishwasher and we could not find a wiring diagram for the motor. Same 4 wire setup. After doing what you did with a multi-meter and resistance we also figured it out and now my son wants to do all kinds of stuff with this motor. Awesome, never too old to learn something.
Even though I am an electrical engineer, I learn a lot from you. The compass and AA cell is a great idea if for visualizing the field. The approach to resistance analysis was clever, too.
I enjoy figuring out appliance motors. I've got a few 2 and 3 speed washing machine motors figured out and diagrammed up; it's satisfying to know what each and every wire coming off of one of those does. And at the end you have a motor that's usually reversible, multi-speed, and usually surprisingly torquey. They're often free, too, as most folks can't figure them out
You could use a PTC Resistor. refrigerant compressors often use this method. The PTC will go high resistance after a short amount of time and reduce the current to a very small current. You could also rewind a relay with a much thicker wire and put the main winding current through it. When the motor has started the current drops and the relay turns off. This method is also used by refrigeration compressors.
@@ihatenumberinemail thats not what 'resistive start' means, there's no actual resistor there per se, just that the start coil has thinner wires and thus a higher inherent resistance. That component isn't a resistor , its probably a thermal breaker
@@ihatenumberinemail oh yeah. The one I'm talking about is inside the motor. Visible briefly at about 1:05 on the bottom half of the motor, a silvery rectangular thing inside the motor frame
I extracted a motor from a dishwasher last year which was wired exactly like this. I was thinking of solving the starting problem using the type of switch you showed from your dad's table saw. I'm glad to see that's something that was actually done on professional machines. I guess it might be tricky to source a switch like that rated for high voltage applications.
you were on the right track,this motor uses a current relay to start like a fridge compressor.On some dishwashers the motor runs forward to pump water around inside then reverse to drain, great vid.
We just followed your process including the diagrams on an almost identical dishwasher motor (different color wires) and it worked perfectly, what fun. Thank you!
True, I'm not an electrician but I understood your rationale and the process you used to isolate step-by-step solutions was very helpful. Yes, I'm somewhat OCD, so confusing to some usually isn't to me. Do I understand always? NO! But that's OK. I enjoy the process none-the-less. Thanks, Matthias.
I was just looking into understanding current relays (used in small ac and refrig systems) and potential relays (used in larger systems) for switching the start cap in and out. I believe you had that relay wired up as a current relay. Off the shelf, the current relay has large gauge/low resistance winding that only makes the contacts on the start up current but breaks when the lower running current is reached. But they have the problem of rapid cycling as they reach stasis. update: Found a ladder diagram for a dishwasher showing a current relay. Could use one of the HVAC "3 n 1" start capacitor kits in place of the relay, with or without the cap in place.
Great video. I had to go through a similar process for a used big single-phase AC motor and was quite proud of my self-education by the end, although I did get capacitor-zapped twice.
For anyone who cares: The counter weight gives the motor a higher inertial moment to dampen twisting action when motor rotation rate changes. The larger the inertial moment, the harder it is to change the angular momentum which equates to a physical resistance to physical rotation. In static equilibrium, the angular momentum of the housing is zero, by definition (i.e. no rotation of the housing). This can be summarized in the expression dL = Idw where d is differential operator, L angular momentum, I moment of inertia, w angular velocity. When the rotor changes rotation rate (change in angular velocity) the housing wants to counter twist against the rotor twist. The counter weight helps the housing stay put, I.e dampens the impact of rotor twist. Cheers!
You can steal a start switch from a fridge or freezer motor. The hermetic compressors do not use a centrifugal switch as the arc will damage the refrigerant. The coil of the switch is in the power winding lead so when power is applied, the high stall current turns on the relay operating the start winding. When the motor comes up to speed the current drops to run current and the start relay drops out. With a switch you can send the start to either start winding.
@@mickey7660 If available find the service manual for the machine it came from. Look up the wiring diagram. Since it is listed as a mystery, you have more work and need a multimeter, a bench DC power supply, and a pocket compass. With the meter identify all leads that are in sets, such as the run and start winding. If the motor is two speed, there will be a winding that appears to have a "Center tap. Motors that are not reversible will not have two ends of the start winding separate, but one end will be tied to the common of the run. The run winding will have the lowest resistance. If two winding's have almost identical resistance and have a common wire, this is the two run winding on a two speed motor. Power one or the other to common, and never both at the same time. A current powered start relay is gravity dependent so it must operate in the original position. The motor RUN power is fed through the relay coil, so when the motor is first powered, the high current draws in the relay and applies start current to the start winding. The start capacitor is in series with this start relay contact. When the motor comes up to speed, the current drops and the relay drops out the start current. Many diagrams are online. The trick is to identify the start and run windings and possibly multiple run windings for a 2 speed washing machine motor. www.jimdow.com/jimdow/sales/diagrams/refcompressorstartwiring.jpg Some motors do not have start tied to the run so trading the ends to reverse it will start the motor in reverse.
Gained a better understanding about that starter coil. Not a motor expert But I've been a tinkerer since I took a motor out of a cassette player as a kid loved incorporating it with my legos with rubber bands. and so many other applications. Thanks for sharing
Those older style dishwashers have motors that spin both ways, one way drives the water through the sprayers in the tub, then it drains the water out by spinning in the opposite direction. The timer itself on the dishwasher is what switches the starter winding and run winding.
I love this particular video , the ohm’s mathematics and physical real life testing of each of the wires was in-depth knowledge sharing ! Thank you , this will help me out in the near future ! 🧐🧐🧐🇬🇧🇬🇧🇬🇧❤️❤️❤️🤝🤝🤝👍🏻👍🏻👍🏻🤓🤓🤓
I just fixed my old General Electric dish washer that we’ve had for 25 years. The induction motor is pretty big compared to the one in the video, but I think it only produces 1/3 HP. That motor is built so well, I bet it might last for another 10 years or more.
Good job Matthias. Where were you about 3 months ago? I really needed the help then. I had a dishwasher motor very similar to the one you have here. It took me a while to get it figured out, but I was successful in doing so. Amazing I went through almost the same steps you have so clearly shown here in getting it to run. I used the motor to build an 8" disk sander with an odd ball switch, and I must say this baby performs like a brand name product. I use for a switch, a 2 switch box, 1 on and off light switch, in the same box I mounted 2 momentary push buttons for CW or CCW, as someone mention below in comments. To turn it on you flip the light switch at the same time you push your choice of direction button, for just a about 2 seconds and she runs like a horse that's been eating jalapenos. :P
The dish washer wiring diagram has the dark blue (VIOLET on my motor) connecting to LINE. The There is a relay with the coil in series with the main winding (LT BLUE) to NEUTRAL. This relay requires a significant current to energize and pull contacts together. There is also a screw adjustment which my guess is a tension spring to set that current level however crude that might be. When the motor is first powered, a large current will flow in the main winding causing the relay contacts to close and engage the either start winding (BLACK or YELLOW) for a short period of time to set the direction. I measured over 12A peak for start winding at power on by leaving the direction winding disconnected. With either start winding included (without the relay), the current is about 22A peak. After applying power, it takes about 2 ac cycles for the relay to respond and contacts to close. In about 200 ms, the motor speed is sufficient and run current drops below the relay hold current threshold and the contacts open the start winding. The motor current drops to about 3-4 A peak. These measurements were done with a scope and some current and voltage probes.
For these motors with no centrifugal switch, I use something like the Functional Devices RIBU1C relay, with the starter winding on the normally-closed circuit. The relay has a 10-15ms activation time, which is just enough for approximately a single 60hz cycle on both windings - then by the time the relay opens the normally-closed circuit (thereby disconnecting the starter winding), the motor is running. I haven't tested this strategy under higher load to see if ~10ms is enough to get it started; if the motor can't start in that case, I would just look for a slower relay or potentially a similar enclosed component that has a time-delay built in. Once the motor is running with power constant power applied to the main winding, that same power will keep the relay coil energized and keep the starter winding disengaged. The downsides of this approach are 1) The relay stays engaged the whole time 2) If the relay coil fails, the starter coil will stay constantly engaged and likely burn out on most motors. The Functional Devices products are great since they are cheap, mount on a standard 1/2" knockout of a junction box, and happen to be made (or at least assembled) in the US. They have various configurations of contact counts and ampacities.
I've got a very simple solution on an old table saw. The power switch is similar to a light switch, except that it's made up of two levers, one stays down when you flick the switch, that's the primary winding. The other switch is a momentary (I.e. it doesn't latch in the ON position). So when you flick the switch you push down on both, the non-latching switch powers the starter windings, and the latching switch stays down to keep the primary windings powered. Very simple and elegant. Perfectly mechanical solution
Washing machine motors are similar as one direction runs the agitator and the pump but the pump is running backward and the other direction runs the drum to centrifugally spin the clothes and the pump in the direction to empty the water from the washer. Dish washers only have a pump and one direction runs the pump to power the spray arms but runs it backward to drain the tub.
These dishwasher motors use a capacitor to start, not a centrifugal switch. The reason for the 2 directions is for draining the dishwasher usually. (depending on the model)
Centrifugal switches aren't for starting, except that they're in the "on" position to let the capacitor or resistance do the starting. Those switches are for improving performance and safety _after_ starting. Maybe rewatch this video.
The motor you was talking about, is mostly a single phase, and mostly they are mostly have a start capacitor to start it up , and those wires you was talking about that was not connected to the stator is mostly that I think is supposed to be where the capacitor starts it.
I wonder if you could connect a 120v relay to the run winding and use the normally closed contact to power the start winding. I am wondering if the relay contacts would open slow enough to allow the motor to start. I guess worst case you could use a potential starting relay that are made for this purpose that are used for refrigeration compressors and submersible well pumps.
Thanks. I can't understand why people down vote this? You spoke clearly. You were methodical. You explained everything. You even wrote a diagram. I guess the 5 down voters are competing youtubers. Or maybe the secret society of mystery motor manufacturers? Good job!
Couldn't you use a car ignition switch to get a manual switch like the felder saw? It has Off, Run, and Start. Would be usable if it were on a tool, On a dust collector, not so much. But I imagine it's far too weak for a tool at 5 amps.
For the record, there's a simple way the controller can tell if the motor has started (and I'm not saying any appliances DO this, as I'm not in the business): let's say it drives a relay or triac to connect one lead or the other of the resistive start winding to the line for the run winding, and holds that for half a second (or whatever) - when it ceases driving the relay or triac, if the motor is turning, there should be a substantial AC voltage across the start winding. Safely clip a DMM set to appropriate AC voltage range across the start wires, along with a suitable jumper wire from one start wire or the other (CW or CCW) and touch that to the Line as you switch on the motor, and as per your video disconnect that just as soon as it is running, and you'll observe an AC voltage on the DMM, even though the start wire is no longer connected. If you don't touch it off and let the motor hum when you apply power to the run windings, you'll see there is no AC voltage on the start winding. I'd wager one could use the voltage across the starter windings to ascertain if the motor is bogging. CAUTION: the starter wires will also have power on them if you were to say spin start the motor, so don't assume that because YOU aren't energizing the wires by connecting them, that they are safe to have dangling about.
Although I don't have much knowledge of engineering and electronics, it's always fascinating to watch you work. Keep up the great work! :) All the best from the disillusioned UK! Haha
Can you explain how to find rpm of induction motor, as I have one washing machine dryer motor good working, but don't know its rpm, if it is jam then it will need service for freely moving.
@@Durgeshkr00 Sorry, I don't really know how one would do that, although I am sure Matthias does. Perhaps make this as your own comment, so it is more likely that he (or someone else) will see it? :) Good luck! There's also a UA-camr called AvE who is an engineer. Go on his channel and search 'find RPM motor' and see if anything comes up that will help you. :)
Very cool explanation. You could also activate the starter relay with a current loop, since the main motor won't draw the 4+ amps until it's running. Ehud
Not an elegant solution? That self latching relay is brilliant! Maybe if you hook up a capacitor before , it will help with the relay “flutter”. I dont fully know what Im talking about but I hope I sound smart
It is not brilliant, the contacts will break down really fast because of the sparks. I don't know how many times he's going to be able to start his motor with this setup. Maybe 50 times? Maybe 100 times? Maybe 1000 times. It works, yes, it's a nice hack, but it's a band-aid. He'll have to replace it sooner than later.
They had switches like that on old lathes too. The one i kow was a bi-directional switch, the engagement was done on a sleeve, and you'd twist it to the direction you wanted, and as you let go of the handle, it would spring back to neutral and continue with a latching relay. I can't ,for the life of me, remember the brand tho, i ditched mine for a digital controller.
When you open that contact to turn the starter off, you develop a tremendous back EMF across the starter windings, (several KV!) hence the visible spark. To reduce the problem, add a parallel capacitor and large resistor across the starter switch contacts. If you want a more elegant solution to this back EMF problem, perform the switching of the relay during the zero current crossings of the AC waveform. During this period, there is no back EMF energy in the starter windings. Thus, no high Voltage is developed when the relay contacts are opened. If you let this high Voltage problem persist, you will soon damage or destroy the relay contacts!
@@teslakovalaborator All that said, what clever use can be made of this motor aside from powering a dishwasher? It's kind of underpowered for anything useful in the workshop. Maybe, Harbor Freight would be a better choice for reasonably good motors for workshop applications. They don't require messing around with to get them to work for the intended use. I guess it depends on how one values their time.
I stumbled upon this video, and just so happens to have such a dishwasher motor myself. I keep such things thinking one day I will use it. And since these type motors have so many wires, I was wondering how they are wired up to use. Nice presentation and ideas to figure it out. How much actual "HP" does such a motor actually have... I mean a mere 5 amps or there about, it can't drive too much torque...
i wired a 3 phase induction motor (.7kw just a baby lol) in single phase and used a timer to switch the start cap(like 1 second) seemed to work well but i didnt have a load(except grinding a piece of wood on the rotor, which was kinda dangerous). Its cool this motor had two start windings for either direction. most dish washer motors in my country are shaded pole motors
That rod sticking out of the body could also be used to open a switch that is connected to the secondary starter winding. Or, you could have a motion detector rigged to open a switch when the rod is vibrating back and forth. A lot more complicated than necessary.
The direction beeing changeable has some benefits. Maybe have a main switch that turns power on and then two buttons (= momentary switch) to a micro controller wich then closes a starter relay depending on direction. Could be useful for a fancy fan.
Now, what machine do you want to build where you could take advantage of reversible direction? You could just use momentary switches to engage a direction.
I didn't understand pretty much any of this, but I still found it interesting and watched it the whole way through. I'd love to understand this kind of stuff, but I'm not really sure where to start.
Thanks for sharing ur videos with us I’d really love to learn how to find out which one of the 6 or sometime 4 wire that comes out from a motor is + and - and earth
you could also use a main switch and then a momentary switch to choose the direction that also latches a relay to supply the main current top the motor
I have no idea what your talking about but still love your videos and admire the knowledge you have about this type of stuff. I'll always watch and like all of your videos. Plus it's entertaining so see your slow progress into becoming a super villain with a well trained army of mice voles and squirrels by your side.
I've got a top load washing machine motor if you want it. I can't do anything with it. Though I'm not sure if it works, and I don't have the equipment you do to test it out.
Cool video. I'm learning about motors right now and actually grasped most of that. How much did the current draw go down after you turned off the starter winding with the relay?
It requires good knowledge of electricity and motors first. And so the tutorial would be so long that you wouldn't watch it. The whole point is, it's not straightforward.
@@matthiasrandomstuff2221 thanks for your reply. I am good in electronics. But main point is that your explanations are easily understandable. You can make in part wise. Don't think that I get bored from your videos, but actually i enjoy your video as it is in lucid and have proofs. Length doesn't matters. I had watched and enjoyed 1hr 13 min. Of one youtuber 'mbahtedjo' about brushless dc motor and made my own successful bldc motor with the help of that video. Infact I love your videos very much. Thank once again.
You could probably use a potential start Relay or a current start Relay in lieu of a centrifugal switch. Potential meaning voltage. Commonly used on small fractional horse ac compressors. Good luck. Liking the technical videos!
I got a large water booster pump that had shipping damage and destroyed the centrifugal switch. I used a small contactor with a pair of momentary buttons to control it. By using a DPST start button I just used one set of contacts to energize the contactor, wired for latching, and ran the start coil to the other set of contacts. You couldn't press the start fast enough that it would fail to start. So I felt ok that anyone could use it.
Hi Mathias! Nice design with using the 24V relay for starting! This motor had either a current-relay or a PTC start device. The PTC device is just as you describe; it's a timed device which kicks out the start winding after carrying current for a moment. These are used on fridge compressors extensively. A current-relay is also really common with dishwashers and older fridge compressors. As you know, the main winding takes a lot of current when it's stalled. The current drops as the motor speed picks up. A current relay engages the start winding when the main winding is taking a high current, and then drops out when the current is less. Here is a video where I show a current relay that needed a coil rewound. ua-cam.com/video/0qNh3oYrJxE/v-deo.html If you're interested in a PTC start device, look at your local HVAC service parts company. They will have a Supco device which has an overload breaker as well as the start device. They call them a ROx1 with RO81 being for small motors, and RO41 for larger ones. :)
Most likely it has a capacitor start motor. The last time I took apart a dishwasher, the circulating pump motor had a 15uf capacitor. But the drain pump had no capacitor or shading poles. So the drain pump had a permanent magnet motor that can turn either directions.
If you put a capacitor parallel to the induction coil of the solenoid that would give you a single starting impulse. The right value would depend on the resistance of the coil (the idea is that the impulse would be triggered once the capacitor is charged)
With no load, since the VA product is 516 but it is only consuming 167W, this means the current and voltage are about 71 degrees out of phase. As you increase the motor load, the current will rise and also come closer in phase with the voltage, both causing the true power consumption to increase. None of this really reflects on the efficiency of the motor, though. Of course, the resistance in the house wiring will incur the same losses on the 4.3 amps regardless of its phase from the supply voltage (the voltage drop in the wiring will be in phase with the current). Aside that, I was wondering what the purpose of that side-arm was.
Even though I know nothing about motors, I find trying to wrap my head around their workings to be fascinating. I do work for the electric company and I update maps, and while electrical knowledge is not necessary because the maps are visual, I think that it could benefit me to be familiar with how things work.
I don't know anything about motors but I can change everything out on a dishwasher. I want to use this motor to make a 2x72 belt sander, would this be the best way to wire it?
Holy crap - I can not believe I found this video. I'm working on my Kenmore Diswasher 665.15772990 right now and the motor has failed. It tries to start up but it struggles to move. (Motor Part #3377333). This video was very interesting and helpful - I'm going to play around with the motor now and see if I can fix it. Thanks!
Excellent video, interesting techniques, thank you, (perhaps the machine it came from had an external start relay as I'm sure many other functions would want to know or verify spin)
The relay circuit looks simple and elegant since it relies on feedback and makes sure to power the starter winding until the motor has started spinning. Maybe a small half-wave rectifier (series diode) can be used to power the relay coil so as to not cause the sparks due to AC.
@@VikasVJois switch contacts bounce. That's what they do. They do it even with no current applied. It is just your limited human perception can't notice it. Which is why debouncing circuitry is a thing and mercury wetted contacts too. BTW relays hold just fine with AC current. The real solution to the problem of switch arc is called a snubber network.
@@VikasVJois it sure is. Switch bounce is something I became aware of back in the 70s when I used to mess with TTL. What's one to us is tens of thousands to more sensitive hardware.
Stupid question: can you grab useful information from the UL listing number? When I went on the website it looks like they wanted registration to access the database.
Use 2 resistors in series with the relay. Short one of them with an extra set of contacts when the relay engages. That should give you some hysteresis to get the relay stabil.
Great video but when you checked the motor current you forgot about power factor. It was drawing several amps but not many Watts so that doesn't mean it isn't very efficient like you said.
Very cool video.What if you had a single pole switch for the main and one momentary push button one side for forward and another on the other side for reverse. It's all manually done on the switch.
Ideally, switching on and turning on the starter happens at the same time. Just having an on switch that doesn't start the motor is fine until somebody other than you turns it on.
you could try using a on/off toggle switch for the primary winding and two push button switches (one for each direction) that connect the starter windings for as long as you press them
Wow! I have a motor just like that! I actually had 3, but I burned two of them from trial and error discovering how to power them. I have a bunch of dishwasher motors, but alot of them are capacitor start.
Thank you for the shoutout, and nice troubleshooting.
Great to see you here, love your channel
Jeremy is the man!
Thanks Matt. My 16yo son took apart an old dishwasher and we could not find a wiring diagram for the motor. Same 4 wire setup. After doing what you did with a multi-meter and resistance we also figured it out and now my son wants to do all kinds of stuff with this motor. Awesome, never too old to learn something.
Hey Leon, what did your boy make with the motor? :) If nothing yet, might I suggest building a massive Van de Graff generator? 🤓⚡
Even though I am an electrical engineer, I learn a lot from you. The compass and AA cell is a great idea if for visualizing the field. The approach to resistance analysis was clever, too.
I enjoy figuring out appliance motors. I've got a few 2 and 3 speed washing machine motors figured out and diagrammed up; it's satisfying to know what each and every wire coming off of one of those does. And at the end you have a motor that's usually reversible, multi-speed, and usually surprisingly torquey. They're often free, too, as most folks can't figure them out
I almost jumped when when you connected power to the motor. I've been watching too much Electro Boom. Heh.
IKR? I said the same thing.
You know a friend is a good friend when they save motors for you. :)
You could use a PTC Resistor. refrigerant compressors often use this method.
The PTC will go high resistance after a short amount of time and reduce the current to a very small current.
You could also rewind a relay with a much thicker wire and put the main winding current through it.
When the motor has started the current drops and the relay turns off.
This method is also used by refrigeration compressors.
I see there's some sort of component on his motor attached to one of the leads. I assumed it was a thermal breaker, but I wonder if it's a PTC relay?
@@unregistereduser2 He said that's just a resistor.
@@ihatenumberinemail thats not what 'resistive start' means, there's no actual resistor there per se, just that the start coil has thinner wires and thus a higher inherent resistance. That component isn't a resistor , its probably a thermal breaker
@@unregistereduser2 Ah, I was talking about the component at 8:16.
@@ihatenumberinemail oh yeah. The one I'm talking about is inside the motor. Visible briefly at about 1:05 on the bottom half of the motor, a silvery rectangular thing inside the motor frame
This motor is usually controlled thru electronic control.
P3 Motor Main Winding BU
P4 Motor Aux Winding - Wash Y
P5 Motor Aux Winding - Drain GY
Jeremy is awesome- thanks for giving his some love.
I extracted a motor from a dishwasher last year which was wired exactly like this. I was thinking of solving the starting problem using the type of switch you showed from your dad's table saw. I'm glad to see that's something that was actually done on professional machines. I guess it might be tricky to source a switch like that rated for high voltage applications.
Lathes have this kind of switch too. Cheapo (for their time) hobby lathes in particular.
you were on the right track,this motor uses a current relay to start like a fridge compressor.On some dishwashers the motor runs forward to pump water around inside then reverse to drain, great vid.
I couldn't figure out how to jump start my motor until I watched this and you helped me figure it out - thanks
We just followed your process including the diagrams on an almost identical dishwasher motor (different color wires) and it worked perfectly, what fun. Thank you!
True, I'm not an electrician but I understood your rationale and the process you used to isolate step-by-step solutions was very helpful. Yes, I'm somewhat OCD, so confusing to some usually isn't to me. Do I understand always? NO! But that's OK. I enjoy the process none-the-less. Thanks, Matthias.
I was just looking into understanding current relays (used in small ac and refrig systems) and potential relays (used in larger systems) for switching the start cap in and out. I believe you had that relay wired up as a current relay. Off the shelf, the current relay has large gauge/low resistance winding that only makes the contacts on the start up current but breaks when the lower running current is reached. But they have the problem of rapid cycling as they reach stasis.
update: Found a ladder diagram for a dishwasher showing a current relay. Could use one of the HVAC "3 n 1" start capacitor kits in place of the relay, with or without the cap in place.
You are one smart and talented person, good job.
Great video. I had to go through a similar process for a used big single-phase AC motor and was quite proud of my self-education by the end, although I did get capacitor-zapped twice.
For anyone who cares: The counter weight gives the motor a higher inertial moment to dampen twisting action when motor rotation rate changes. The larger the inertial moment, the harder it is to change the angular momentum which equates to a physical resistance to physical rotation. In static equilibrium, the angular momentum of the housing is zero, by definition (i.e. no rotation of the housing). This can be summarized in the expression dL = Idw where d is differential operator, L angular momentum, I moment of inertia, w angular velocity. When the rotor changes rotation rate (change in angular velocity) the housing wants to counter twist against the rotor twist. The counter weight helps the housing stay put, I.e dampens the impact of rotor twist. Cheers!
You can steal a start switch from a fridge or freezer motor. The hermetic compressors do not use a centrifugal switch as the arc will damage the refrigerant. The coil of the switch is in the power winding lead so when power is applied, the high stall current turns on the relay operating the start winding. When the motor comes up to speed the current drops to run current and the start relay drops out. With a switch you can send the start to either start winding.
How do I wire this up?
@@mickey7660 If available find the service manual for the machine it came from. Look up the wiring diagram. Since it is listed as a mystery, you have more work and need a multimeter, a bench DC power supply, and a pocket compass. With the meter identify all leads that are in sets, such as the run and start winding. If the motor is two speed, there will be a winding that appears to have a "Center tap. Motors that are not reversible will not have two ends of the start winding separate, but one end will be tied to the common of the run. The run winding will have the lowest resistance. If two winding's have almost identical resistance and have a common wire, this is the two run winding on a two speed motor. Power one or the other to common, and never both at the same time. A current powered start relay is gravity dependent so it must operate in the original position. The motor RUN power is fed through the relay coil, so when the motor is first powered, the high current draws in the relay and applies start current to the start winding. The start capacitor is in series with this start relay contact. When the motor comes up to speed, the current drops and the relay drops out the start current. Many diagrams are online. The trick is to identify the start and run windings and possibly multiple run windings for a 2 speed washing machine motor. www.jimdow.com/jimdow/sales/diagrams/refcompressorstartwiring.jpg
Some motors do not have start tied to the run so trading the ends to reverse it will start the motor in reverse.
@@isettech thanks for your help I appreciate it
Gained a better understanding about that starter coil. Not a motor expert But I've been a tinkerer since I took a motor out of a cassette player as a kid loved incorporating it with my legos with rubber bands. and so many other applications. Thanks for sharing
I admit, I don't exactly understand what you did. But I will, after some study. I found this useful, in an inspirational sense.
Good stuff. I never used a compass in a motor to try to figure windings out in it.
Thanks for some free electrical education! You have taught me a lot through the years! Keep it coming please
Those older style dishwashers have motors that spin both ways, one way drives the water through the sprayers in the tub, then it drains the water out by spinning in the opposite direction. The timer itself on the dishwasher is what switches the starter winding and run winding.
I love this particular video , the ohm’s mathematics and physical real life testing of each of the wires was in-depth knowledge sharing !
Thank you , this will help me out in the near future ! 🧐🧐🧐🇬🇧🇬🇧🇬🇧❤️❤️❤️🤝🤝🤝👍🏻👍🏻👍🏻🤓🤓🤓
Very cool! I am impressed by Matthias's sleuthing.
So many people taking an interest in the world of electrical engineering is great to see.
Everything is confusing until you start learning and understanding on the given subject. Thank you for making these videos
I just fixed my old General Electric dish washer that we’ve had for 25 years. The induction motor is pretty big compared to the one in the video, but I think it only produces 1/3 HP. That motor is built so well, I bet it might last for another 10 years or more.
i love you. The out of the box things you come up with are great.
Good job Matthias. Where were you about 3 months ago? I really needed the help then. I had a dishwasher motor very similar to the one you have here. It took me a while to get it figured out, but I was successful in doing so. Amazing I went through almost the same steps you have so clearly shown here in getting it to run. I used the motor to build an 8" disk sander with an odd ball switch, and I must say this baby performs like a brand name product. I use for a switch, a 2 switch box, 1 on and off light switch, in the same box I mounted 2 momentary push buttons for CW or CCW, as someone mention below in comments. To turn it on you flip the light switch at the same time you push your choice of direction button, for just a about 2 seconds and she runs like a horse that's been eating jalapenos. :P
Good on you for the Fielding link. You and he could have some interesting conversations.
The dish washer wiring diagram has the dark blue (VIOLET on my motor) connecting to LINE. The There is a relay with the coil in series with the main winding (LT BLUE) to NEUTRAL. This relay requires a significant current to energize and pull contacts together. There is also a screw adjustment which my guess is a tension spring to set that current level however crude that might be. When the motor is first powered, a large current will flow in the main winding causing the relay contacts to close and engage the either start winding (BLACK or YELLOW) for a short period of time to set the direction.
I measured over 12A peak for start winding at power on by leaving the direction winding disconnected. With either start winding included (without the relay), the current is about 22A peak.
After applying power, it takes about 2 ac cycles for the relay to respond and contacts to close. In about 200 ms, the motor speed is sufficient and run current drops below the relay hold current threshold and the contacts open the start winding. The motor current drops to about 3-4 A peak. These measurements were done with a scope and some current and voltage probes.
For these motors with no centrifugal switch, I use something like the Functional Devices RIBU1C relay, with the starter winding on the normally-closed circuit. The relay has a 10-15ms activation time, which is just enough for approximately a single 60hz cycle on both windings - then by the time the relay opens the normally-closed circuit (thereby disconnecting the starter winding), the motor is running. I haven't tested this strategy under higher load to see if ~10ms is enough to get it started; if the motor can't start in that case, I would just look for a slower relay or potentially a similar enclosed component that has a time-delay built in.
Once the motor is running with power constant power applied to the main winding, that same power will keep the relay coil energized and keep the starter winding disengaged. The downsides of this approach are 1) The relay stays engaged the whole time 2) If the relay coil fails, the starter coil will stay constantly engaged and likely burn out on most motors.
The Functional Devices products are great since they are cheap, mount on a standard 1/2" knockout of a junction box, and happen to be made (or at least assembled) in the US. They have various configurations of contact counts and ampacities.
I’m not a motor expert by any means but Matthais that was brilliant, I enjoyed it very much thank you, 👌🏼
Another starting strategy I've seen these motors have is a current sensing relay that engages the start winding when there is locked-rotor current.
I've got a very simple solution on an old table saw. The power switch is similar to a light switch, except that it's made up of two levers, one stays down when you flick the switch, that's the primary winding. The other switch is a momentary (I.e. it doesn't latch in the ON position). So when you flick the switch you push down on both, the non-latching switch powers the starter windings, and the latching switch stays down to keep the primary windings powered. Very simple and elegant. Perfectly mechanical solution
Could that weight be some kind of harmonic dampener? Very interesting about figuring out motor wiring.
Washing machine motors are similar as one direction runs the agitator and the pump but the pump is running backward and the other direction runs the drum to centrifugally spin the clothes and the pump in the direction to empty the water from the washer. Dish washers only have a pump and one direction runs the pump to power the spray arms but runs it backward to drain the tub.
These dishwasher motors use a capacitor to start, not a centrifugal switch.
The reason for the 2 directions is for draining the dishwasher usually. (depending on the model)
Centrifugal switches aren't for starting, except that they're in the "on" position to let the capacitor or resistance do the starting. Those switches are for improving performance and safety _after_ starting. Maybe rewatch this video.
You can use a potential relay. They're used in refrigerators to start the compressor.
I was going to suggest this, also.
The motor you was talking about, is mostly a single phase, and mostly they are mostly have a start capacitor to start it up , and those wires you was talking about that was not connected to the stator is mostly that I think is supposed to be where the capacitor starts it.
I wonder if you could connect a 120v relay to the run winding and use the normally closed contact to power the start winding. I am wondering if the relay contacts would open slow enough to allow the motor to start.
I guess worst case you could use a potential starting relay that are made for this purpose that are used for refrigeration compressors and submersible well pumps.
Pretty interesting
Thanks. I can't understand why people down vote this? You spoke clearly. You were methodical. You explained everything. You even wrote a diagram. I guess the 5 down voters are competing youtubers. Or maybe the secret society of mystery motor manufacturers? Good job!
Probably from people who could not follow
big dishwasher doesn't want people to know
Maybe they're using a touch screen device (cell phone) where the up/down icons are close together. They just fat-fingered the up button.
Couldn't you use a car ignition switch to get a manual switch like the felder saw?
It has Off, Run, and Start. Would be usable if it were on a tool, On a dust collector, not so much. But I imagine it's far too weak for a tool at 5 amps.
A boat ignition is better
60 - 100amps
Great ideas! You could also use a pushbutton starter, or the start button from a clothes dryer.
For the record, there's a simple way the controller can tell if the motor has started (and I'm not saying any appliances DO this, as I'm not in the business): let's say it drives a relay or triac to connect one lead or the other of the resistive start winding to the line for the run winding, and holds that for half a second (or whatever) - when it ceases driving the relay or triac, if the motor is turning, there should be a substantial AC voltage across the start winding. Safely clip a DMM set to appropriate AC voltage range across the start wires, along with a suitable jumper wire from one start wire or the other (CW or CCW) and touch that to the Line as you switch on the motor, and as per your video disconnect that just as soon as it is running, and you'll observe an AC voltage on the DMM, even though the start wire is no longer connected. If you don't touch it off and let the motor hum when you apply power to the run windings, you'll see there is no AC voltage on the start winding.
I'd wager one could use the voltage across the starter windings to ascertain if the motor is bogging.
CAUTION: the starter wires will also have power on them if you were to say spin start the motor, so don't assume that because YOU aren't energizing the wires by connecting them, that they are safe to have dangling about.
Although I don't have much knowledge of engineering and electronics, it's always fascinating to watch you work. Keep up the great work! :) All the best from the disillusioned UK! Haha
Can you explain how to find rpm of induction motor, as I have one washing machine dryer motor good working, but don't know its rpm, if it is jam then it will need service for freely moving.
@@Durgeshkr00 Sorry, I don't really know how one would do that, although I am sure Matthias does. Perhaps make this as your own comment, so it is more likely that he (or someone else) will see it? :) Good luck! There's also a UA-camr called AvE who is an engineer. Go on his channel and search 'find RPM motor' and see if anything comes up that will help you. :)
@@jezzermeii thanks
Very cool explanation. You could also activate the starter relay with a current loop, since the main motor won't draw the 4+ amps until it's running.
Ehud
I love to see a fountain pen in use. Great video.
Not an elegant solution? That self latching relay is brilliant! Maybe if you hook up a capacitor before , it will help with the relay “flutter”. I dont fully know what Im talking about but I hope I sound smart
It is not brilliant, the contacts will break down really fast because of the sparks. I don't know how many times he's going to be able to start his motor with this setup. Maybe 50 times? Maybe 100 times? Maybe 1000 times.
It works, yes, it's a nice hack, but it's a band-aid. He'll have to replace it sooner than later.
They had switches like that on old lathes too. The one i kow was a bi-directional switch, the engagement was done on a sleeve, and you'd twist it to the direction you wanted, and as you let go of the handle, it would spring back to neutral and continue with a latching relay. I can't ,for the life of me, remember the brand tho, i ditched mine for a digital controller.
When you open that contact to turn the starter off, you develop a tremendous back EMF across the starter windings, (several KV!) hence the visible spark. To reduce the problem, add a parallel capacitor and large resistor across the starter switch contacts. If you want a more elegant solution to this back EMF problem, perform the switching of the relay during the zero current crossings of the AC waveform. During this period, there is no back EMF energy in the starter windings. Thus, no high Voltage is developed when the relay contacts are opened. If you let this high Voltage problem persist, you will soon damage or destroy the relay contacts!
Just modify that shitty SSR, as far as I know, they have ZCD latch.
@@teslakovalaborator All that said, what clever use can be made of this motor aside from powering a dishwasher? It's kind of underpowered for anything useful in the workshop. Maybe, Harbor Freight would be a better choice for reasonably good motors for workshop applications. They don't require messing around with to get them to work for the intended use. I guess it depends on how one values their time.
At 8:43 some capacitor could probably help avoid those sparks. Thanks for the video Matthias!
I stumbled upon this video, and just so happens to have such a dishwasher motor myself. I keep such things thinking one day I will use it. And since these type motors have so many wires, I was wondering how they are wired up to use. Nice presentation and ideas to figure it out. How much actual "HP" does such a motor actually have... I mean a mere 5 amps or there about, it can't drive too much torque...
i wired a 3 phase induction motor (.7kw just a baby lol) in single phase and used a timer to switch the start cap(like 1 second) seemed to work well but i didnt have a load(except grinding a piece of wood on the rotor, which was kinda dangerous). Its cool this motor had two start windings for either direction. most dish washer motors in my country are shaded pole motors
That rod sticking out of the body could also be used to open a switch that is connected to the secondary starter winding.
Or, you could have a motion detector rigged to open a switch when the rod is vibrating back and forth. A lot more complicated than necessary.
The direction beeing changeable has some benefits.
Maybe have a main switch that turns power on and then two buttons (= momentary switch) to a micro controller wich then closes a starter relay depending on direction.
Could be useful for a fancy fan.
Now, what machine do you want to build where you could take advantage of reversible direction? You could just use momentary switches to engage a direction.
An old barrel type car ignition would give you the type of switch you described on the table saw. May have to use some relays to handle the current.
I use a momentary switch to run the start windings. That allows me to use 2 momentary switches to have both directions of run.
I didn't understand pretty much any of this, but I still found it interesting and watched it the whole way through. I'd love to understand this kind of stuff, but I'm not really sure where to start.
DC brushed motors
Thanks for sharing ur videos with us
I’d really love to learn how to find out which one of the 6 or sometime 4 wire that comes out from a motor is + and - and earth
you could also use a main switch and then a momentary switch to choose the direction that also latches a relay to supply the main current top the motor
I can confirm, I'm not a motor expert and found this confusing. But it was interesting to watch your process.
I have no idea what your talking about but still love your videos and admire the knowledge you have about this type of stuff. I'll always watch and like all of your videos. Plus it's entertaining so see your slow progress into becoming a super villain with a well trained army of mice voles and squirrels by your side.
I've got a top load washing machine motor if you want it. I can't do anything with it. Though I'm not sure if it works, and I don't have the equipment you do to test it out.
Cool video. I'm learning about motors right now and actually grasped most of that. How much did the current draw go down after you turned off the starter winding with the relay?
Please make a complete tutorial for identify a capacitor start and capacitor run induction motor.
Thanks
It requires good knowledge of electricity and motors first. And so the tutorial would be so long that you wouldn't watch it. The whole point is, it's not straightforward.
@@matthiasrandomstuff2221 thanks for your reply.
I am good in electronics. But main point is that your explanations are easily understandable.
You can make in part wise.
Don't think that I get bored from your videos, but actually i enjoy your video as it is in lucid and have proofs. Length doesn't matters.
I had watched and enjoyed 1hr 13 min. Of one youtuber 'mbahtedjo' about brushless dc motor and made my own successful bldc motor with the help of that video.
Infact I love your videos very much.
Thank once again.
Love the shoutout to Jeremy!
Jeremy is awesome. Well worth a look.
You could probably use a potential start Relay or a current start Relay in lieu of a centrifugal switch. Potential meaning voltage. Commonly used on small fractional horse ac compressors. Good luck. Liking the technical videos!
I got a large water booster pump that had shipping damage and destroyed the centrifugal switch. I used a small contactor with a pair of momentary buttons to control it. By using a DPST start button I just used one set of contacts to energize the contactor, wired for latching, and ran the start coil to the other set of contacts. You couldn't press the start fast enough that it would fail to start. So I felt ok that anyone could use it.
Hi Mathias! Nice design with using the 24V relay for starting!
This motor had either a current-relay or a PTC start device.
The PTC device is just as you describe; it's a timed device which kicks out the start winding after carrying current for a moment. These are used on fridge compressors extensively.
A current-relay is also really common with dishwashers and older fridge compressors. As you know, the main winding takes a lot of current when it's stalled. The current drops as the motor speed picks up. A current relay engages the start winding when the main winding is taking a high current, and then drops out when the current is less. Here is a video where I show a current relay that needed a coil rewound. ua-cam.com/video/0qNh3oYrJxE/v-deo.html
If you're interested in a PTC start device, look at your local HVAC service parts company. They will have a Supco device which has an overload breaker as well as the start device. They call them a ROx1 with RO81 being for small motors, and RO41 for larger ones. :)
Too good! Really liked the way you explain things.
Most likely it has a capacitor start motor. The last time I took apart a dishwasher, the circulating pump motor had a 15uf capacitor. But the drain pump had no capacitor or shading poles. So the drain pump had a permanent magnet motor that can turn either directions.
lots of cheap motors just use resistive start. Just because your diswasher used a capacitor doesn't mean this one did.
If you put a capacitor parallel to the induction coil of the solenoid that would give you a single starting impulse. The right value would depend on the resistance of the coil (the idea is that the impulse would be triggered once the capacitor is charged)
Yes! He’s back! Great video.
Could you use a simple timer like a 555 or any of the dozens to control a relay or ssr for a set amount of time to turn it on?
With no load, since the VA product is 516 but it is only consuming 167W, this means the current and voltage are about 71 degrees out of phase. As you increase the motor load, the current will rise and also come closer in phase with the voltage, both causing the true power consumption to increase. None of this really reflects on the efficiency of the motor, though. Of course, the resistance in the house wiring will incur the same losses on the 4.3 amps regardless of its phase from the supply voltage (the voltage drop in the wiring will be in phase with the current).
Aside that, I was wondering what the purpose of that side-arm was.
Even though I know nothing about motors, I find trying to wrap my head around their workings to be fascinating. I do work for the electric company and I update maps, and while electrical knowledge is not necessary because the maps are visual, I think that it could benefit me to be familiar with how things work.
Very informative. Maybe make it a "high tech" motor with an Arduino and a couple relays. Would be more work but would be a fun project.
I don't know anything about motors but I can change everything out on a dishwasher. I want to use this motor to make a 2x72 belt sander, would this be the best way to wire it?
Holy crap - I can not believe I found this video. I'm working on my Kenmore Diswasher 665.15772990 right now and the motor has failed. It tries to start up but it struggles to move. (Motor Part #3377333).
This video was very interesting and helpful - I'm going to play around with the motor now and see if I can fix it. Thanks!
Excellent video, interesting techniques, thank you, (perhaps the machine it came from had an external start relay as I'm sure many other functions would want to know or verify spin)
The relay circuit looks simple and elegant since it relies on feedback and makes sure to power the starter winding until the motor has started spinning. Maybe a small half-wave rectifier (series diode) can be used to power the relay coil so as to not cause the sparks due to AC.
You don't think direct current causes arcs?
@@1pcfred it does, just once. But in this case the relay arm is jittering around and causing multiple sparks because of alternating current
@@VikasVJois switch contacts bounce. That's what they do. They do it even with no current applied. It is just your limited human perception can't notice it. Which is why debouncing circuitry is a thing and mercury wetted contacts too. BTW relays hold just fine with AC current. The real solution to the problem of switch arc is called a snubber network.
@@1pcfred yeah. It's the mechanical bouncing of the contacts
@@VikasVJois it sure is. Switch bounce is something I became aware of back in the 70s when I used to mess with TTL. What's one to us is tens of thousands to more sensitive hardware.
Love hearing your thought process, thanks for doing this in real time. I'm sub'd, wanna see more.
Stupid question: can you grab useful information from the UL listing number? When I went on the website it looks like they wanted registration to access the database.
I'm buying the components online you say that's a 40 volt resistor?
To Mathias: The centrifugal switch dis connects the start capacitor when the motor builds 2/3 of its speed
yes, that's what the centrifugal switch does if there is one. This one doesn't have such a switch. Please do watch the video.
Really enjoyed this video.
The harmonic weight is very interesting
Use 2 resistors in series with the relay. Short one of them with an extra set of contacts when the relay engages. That should give you some hysteresis to get the relay stabil.
Great video but when you checked the motor current you forgot about power factor. It was drawing several amps but not many Watts so that doesn't mean it isn't very efficient like you said.
Very cool video.What if you had a single pole switch for the main and one momentary push button one side for forward and another on the other side for reverse. It's all manually done on the switch.
Ideally, switching on and turning on the starter happens at the same time. Just having an on switch that doesn't start the motor is fine until somebody other than you turns it on.
you could try using a on/off toggle switch for the primary winding and two push button switches (one for each direction) that connect the starter windings for as long as you press them
I don't want separate switches for the starter winding. The starter should turn on at the same time as the main winding, in one motion.
Thanks this was exactly what i needed to know. Keep it up much appreciated!
Would it make a wind turbine Motor Matthias??
This is actually very useful for me right now. Just bought a motor from a surplus store with 6 wires!
Wow! I have a motor just like that! I actually had 3, but I burned two of them from trial and error discovering how to power them. I have a bunch of dishwasher motors, but alot of them are capacitor start.