Hands down this is the best video on TH-cam. No stupid music, perfectly clear explanations and real world examples. I have a whole house fan that I need to reverse and now I have 100% confidence in my ability to at least check if it is possible. I knew little about single phase motors before seeing this. Now I totally understand them. Thank you.
Even though I have a bachelor degree in Electrical Engineering and my profession is designing electronics, I found this video to be very interesting and informative. Thank you for taking the time to make it!
About reversing single phase induction motors, and how the starter circuit works. woodgears.ca/motors/reversing.html (and there are still a few induction motor topics left to cover!)
Matthias Wandel That is starting to make a LOT more sense now. I have two washing machine motors, one of which I hope to turn one into a table saw one day and wondered why they had a beefy capacitor on them. Keep the videos on this topic coming ;)
Matthias Wandel Another way to reverse a single phase motor: remove the capacitor, wind a string on the pulley in appropriate direction, pull hard on it to get it spinning and switch AC on shortly after. It will happily spin in the other direction but only by mechanical start.
Wayne Johnson Probably. But potential can be wound back. The first step is to get the motor moving correctly. Then I'll worry about ratios and torque later ;)
This is why I like your videos, Matthias. You can explain things that I have little knowledge about in terms that make it easier to understand. Now, can you make a video about women, please?
I just bought a 3/4 horse induction motor today at a second hand store. The plate didn't say anything about reversing motor, but now I know what to look for. Thanks!
Excellent video... I'm a Certified Electronics Technician (CET) so I have a good understanding of electronics... but never really "got" how the motor reversing worked... your video was very clear and easy to follow. Thanks! (I'm passing it along to be used in some training classes,)
VERY TO THE POINT, SIMPLISTICALLY BLOCK DIAGRAM PRESENTED ! BRAVO MATE !!! A SIMPLE EXPLANATION , OF A VERY TECHNICALLY COMBINED PROCEDURES FOR REVERSING DIRECTION OF A SINGLE & 3 PHASE MOTOR WIRING, AGAIN SPELLED/OUT SO VERY EASY TO UNDERSTAND THE IF/THAN. A TECHNICAL PROCEDURE-VERY WELL COMPACTED VIDEO, COVERING ALL THE MAIN CAN & CAN'T DOs' . IT IS SO WELL PRESENTED WITH A "HANDS-ON SIMPLISTIC ILLUSTRATION ! AGAIN, BRAVO ! I HAVE SEEN ALL YOUR VIDEOS & COULD NOT DISAGREE ON ANY OF THEM !. IT IS AN ART TO PRESENTING SOMETHING TECHNICAL IN A EASY-PEEZY TO UNDERSTAND PRESENTATION !👊👊💥🎯
Great explanation of the why! I have known the how for 40 years but have never known the why. Thanks for that. It never ceases to amaze me how giant corporations will step over a dollar to save a dime. It would cost next to nothing to add 1 wire pigtail to that motor and make it exactly twice as useful having a dual rotation. I really enjoy all of your videos.
Matthias, I was able to reverse my non-reversible motor (an A.O. Smith, 1/8 horse power) without altering the coils. I simply pulled off the casing ends and flipped the rotor end-for-end. After this, the motor ran in the opposite direction. It may not be possible to do this with all non-reversing motors, but on this one it worked perfectly! The motor powered a heavy-duty orbital buffer that shook so violently that it was nearly impossible to use. I disassembled it, removing the orbital counterweight unit and bolted the buffer disc holder directly to the motor shaft. I thought I had to reverse the motor, which it turned out that I did not have to do, however, curiosity got the better of me and I had to test my theory: that I could just turn the rotor end-for-end to get reverse rotation. It works and was easy to do on this motor. Thanks for your educational videos! Will
Perfect explanation of the exact puzzle we've been struggling with at my work. Can't wait to get to work in the morning and share with the guys. Thank you Matthias!
Considering myself highly interested in all kinds of technical stuff, I had to live 67 years until getting such clear explanations. You are a genius AND very gifted teacher! Thanks!
I rewatch your videos on motors every once in a while and I take in a little bit more each time. Good stuff to know, I sometimes find myself repairing swamp coolers and air conditioners, and these videos have helped me out with it twice now.
Thank you for taking time to explain these kinds of things. I like your simple drawings and explanations and the bridging of the gap between the diagram and the physical item. It really fills in the pieces of the puzzle nicely.
As a refrigeration/hvac mechanic I havent had to get this deep in to motors since my trade school days. I still do love hearing about the theoretical side of things. Thanks for the great video!
I really like seeing these sorts of videos from you. Its very interesting to see simplified in such a way. With so many people posting novice DIY videos, this is refreshing.
I had the situation at 7:45 with an unmarked motor where I had to disconnect all of the wires, ohm them to see which ones were which and then I was able to confidently unsolder and resolver the switchover, close it back up and low and behold, it worked! Thanks Matthias!
OMG!!!... You've just explained so much in such a short amount of time in three videos, why can't schools do this? I always got the DC bit, forward/reverse/speed, 3 phase I'll never use domestically, so not a big deal, but at least I understand the theory now, but it was always single phase AC motors I didn't quite get because of the way AC alternates, I 'assumed' the AC capacitor was there for a 'kick' but had never bothered to go any further into it because I didn't think I'd ever understand it, but Woohoo!!!... Single phase AC, swapping the capacitor round, changes the rotation, so simple!!!... Why did they never bother to tell me that at school!... A video is worth a entire book!!!... Thank you!!!
Finally, a woodworking use for an oscilloscope! I knew there had to be an application, and if anyone would find it, it would be you. Another great and informative video - thanks Matthias.
this worked for my rc helicopter. it's very appreciated that people are so willing to share such pertinent information to fix some things. Thank you for making this video
you have a lot of induction motors... I think you've been collecting them for more than a few years!!! Great explanation. Especially about why some motors are labelled as non-reversible.
I want to thank you for teaching me how to reverse old electric motors. I finally got around to put in a reversing switch on my drill press. You explain the process a lot better than other people who tell us how to reverse drill press motors. My 1937 Delta drill press with a Westinghouse motor was easier than I expected. Once I open the cover on the motor there's only two terminals where the power wires went in and other wires came off of the windings and I just reverse those two wires that went into the windings to make it run backwards. I put a four gang box on the drill press with three switches, one for the motor, one for the light, and a 4 way wall switch to reverse the motor. My old drill press lacks a few features I wish it had but it was fun putting this feature on it. Now I just need to find a light for it that looks vintage.
Awesome video. I had been looking for a few hours and everyone had different solutions on how to reversing a split phase motor. You explained in one minute what others tried to explain in confusing and possibly incorrect ways. Worked beautifully, thanks.
Very Informative and explained in very clear terms. You present the information at just the right speed keeping my complete attention. Cant stand people who speak way too slow wasting time.
Very interesting and perfectly explained. It rekindled my interest in understanding how things work and the underlying principles that govern . It sort of got my starting circuit going! Didn't miss the fact that you used the word condenser on one occasion. Endearing to anyone of my generation. Thank you. Great video!
Very good explanation. The only thing I disagree with is the comment that the motor at around the 8:30 mark "has to have the coils removed from the motor case or a hole drilled in the case" , to get at the coils common point so it can be split and swapped. As they have to be accessible for the coils to be joined, the common points on these motors are usually buried just under the first layer of coils near the ends of the motor. With a bit of care the wires can be traced back, dug out and split. The process is similar to digging out the common point for 3 phase motors so they can be converted from Y to ∆ connection. I have reversed a number of these motors and always found the common point close to the surface of the coils. I agree that this level of modification is probably beyond a DIY level.
Well after watching your video,I needed a piller drill motor reversed, So with help in identifing the starter windings I went a head and went for gold.And YES " YES" It had worked after watching hundreads of videos l still could not work it out,befor watching your stuff. So Thank you for putting this vid up it certainly help me today,
This is awesome... you make it easy to understand. Did not understand 3 phase before from reading the books. Like 90 or 120 degrees out of phase for 3 phase power. Great Job!
Very much appreciate your explanation! I’m a self taught electrician (TH-cam Electrician’ videos ) and have been having a hard time with changing the direction of the motor I need to put on my table saw .
Good. I knew all that. I'm heading out to look at a table saw which I'm told two other guys tried and failed to reverse the direction. No history but I am guessing someone bought the wrong motor. It's got two new capacitors. Lol. Your awesome and clear is a great brush up and will save time and make me look like i know what im doing. Thanks. Rich
Great presentation. I really like how you explain the concepts and accompany that with the disassembled motors and even the oscilloscope. That made it very easy to follow.
Matthias - Thanks for a great video and excellent explanations too. I have been reading some of the comments. Interestingly ALL the comments are sensible and appropriate. Very often when someone does a good video, people spoil it with their irrelevant and irreverent comments which is annoying. Kudos to you, and keep up your good work.
At about 9:08 I think you read the motor wrong. I believe the label states Clockwise rather then counter clockwise. I might be confusing some thing though. Really like the video because of the explanation and demonstrations the combo of simple words and simple visuals are a great touch! Matthias you are a great teacher, woodworker, engineer, and many more thanks for your videos
I like your video and your diagrams and explanations very much. They are very informative and probably the best I've seen on youtube. I even checked the videos on reversing a drill press motor cuz apparently some people like to reverse those for special purposes. My dad even put a reversing switch on his bench grinder back in the 40s or 50s.
Really interesting. And I agree with below comments. Keep this topic going. I am just coming to understand AC motor and alternator theory of operation. I gain a basic understanding of what is actually happening, when I watch videos such as this, but I don't know enough to have the gut intuition that I have gained with internal combustion engines, which I began learning about as a young boy. I recently bought an older Lima Electric 8KW 12 wire brushless alternator, and since I knew nothing about it, I began to research. The more I found, the more I thought to myself, "Wow, this is amazing!"
So the start winding will likely have higher resistance than the run winding. In fact, the start winding will likely measure open as the start capacitor is charged by an ohmmeters DC potential.
I enjoy your videos and they are very informative. Could it be that they don't want the motor reversed because instead of the starter switch arm dragging on the pressure collar that it would be pushing toward the pivot point like backing up a trailer behind a vehicle? Would that make it want to break off easier (maybe sooner than later)?
You answered a question I had about my old GE reversible boat davit motors. One of them wont start so i have to give its large pulley a shove to get it going. I plan to first replace the start capacitor. If that doesnt fix it I'll assume its the connections to the start winding or the winding itself. Thanks!
Thanks for the video, it was very helpful. I ordered a brand new motor for my tablesaw from grizzly and missed that the rotation was clockwise and I needed a counterclockwise motor. It was not reversible, but I was able to isolate the start windings and switch the polarity.
Ramekenas With the use of a homemade inductive pickup, oscilloscopes can be useful in the garage as well. (You really could see whats happening on the spark plug wires) Whats really cool now is that oscilloscopes that used to cost 5-15 thousand dollars (analog) a couple decades ago,can now be had for a couple hundred dollars or less on ebay and craigslist.
Thank you so much for making this very informative and easy to understand (if you're versed in electronics) video. I was looking to see if I could reverse the rotation on my drill press and found this video and it had every piece of information I was looking for. Thanks for taking the time to put it together.
I have a motor like this on my bandsaw. I want to replace the switch with a magnetic relay switch but the old switch only had one black and one white while I need the two black and two white to hold the magnet together during operation... do you have any experience with this? Where to find the other white and black wire? Thanks a lot. Love your videos.
Matthias, love the explanation. I have a 3/4hp boat lift motor that only runs in one direction. It was full of mud daubers, cleaned thoroughly as I thought a switch might be stuck however still only one direction. From your video, I see that windings must be good as it wouldn't run in either direction if windings shorted. Any ideas I'd appreciate. Larry in Florida
You can reverse an AC motor like a pump motor. You just replace the capacitor to a reaktor which is used in fluorescent lamp circuits. And thats it! ;) It is very useful when we have just 3 wires out of the coils.
Great video, thanks. I've got a Tuscan 240v induction motor that appears to have 3 coils... there are 6 wires wires emanating from the coils, three colours red, yellow (joined) and green (to capacitor), then there are three black wires also? Any idea how this is set up?
grate video!!! Now I understand a bit mor about AC motors!!!! One question. On a single phase motor like the the first schematic that you show, If i wanted to be bidirectional I will Need a Neutral wire and two live wires to select the rotation right? My question is, What happens if I accidentally activate bothe of the Live whires at the same time. meaning that both windings will be runing at the same phase? whill that create som sort os short circuit or burn the motor, or nothin will happen
I have been doing research on making motors spin different directions and your video is the best! I have Car lift from Atlas that was purchased in US with single phase 230v motor and the motor is spinning in wrong direction. I had changed polarity according to the wiring diagram and it does the same. There are 2 metal strips that has to be changed from vertical to horizontal position and it should make it spin opposite, but it does not. Also swapping 2 positive leads did not do any different. I had another new replacement motor installed and it does the same. Atlas customer service representative suggested the motor winding being defective/installed wrong from the factory. Got new motor installed and it does the same. Any tips what could be wrong with it?
Why so many dislikes? It was a very good explanation of how a motor works. PS Love the "old school" scope. (I started with something similar) Cheers Matthias.
Hi, have an old bench grinder that ive taken to bits for refurbishing. Its a single phase, start and run type with a centrifugal switch, and does not have a capacitor. There are two wires coming from the windings; a switched (on/off) line, and the neutral, which were connected to the lead. Since taking the bench grinder to bits im not sure of the wires polarity, they are both black. Can I take a guess and connect ? Im thinking that if I get them the wrong way round it will reverse the direction of spin only, so easily remedied ! However I dont want to break something. Can I just connect and see which way the motor turns (50/50) chance of me getting it right, or is it not as simple as this ? Bear in mind this is a start/run type motor, Thanks if you can answer, I realise this is a dated vid.
It was woodworking that brought me here but I'm more interested in metalwork now. I recently reversed a motor by swapping two wires, before watching this I didn't know what I was doing exactly before this video. Could you explain how 4 (Or more) pole motors are wired in a video?
hello mr Wandel, i have a single phase motor with 4 wires coming out of the motor. The windings are identical. one winding is connected by a capacitor(permanent). Can i just use the other winding and get it going by hand?
I have a 1.5 hp ac single phase motor with a start capacitor and 4 wires coming out from the motor. I figured out the leads that goes to the starting winding (checked which ones have continuity to the capacitor wires since the resistance was the same on the 2 windings). If i switch the connections of the starting circuit, the motor just hums and does not turn. Is it because the centrifugal switch and the capacitor are not wired in series as mentionned in your text ? Is there something I can do to reverse the rotation ?
I have a Delta Rockwell 12 14 table saw. Is there an easy way to determine if the motor is 3 phase or not? I believe these saws originally were set up for 3 phase but I'm not positive the existing motor is original.
Hello! I have a 4 pole single phase with no terminals (all wires wrapped into the windings) possible to rewire to go in reverse? When I do switch up the wiring, motor hums until I spin the arbor (start capacitor not kicking things on) and the motor sounds a bit rough. Can’t figure it out :(
As you said, the start winding uses a thinner copper wire than the run winding. So if you throw an ohm meter across the windings the Start winding will be somewhere about twice the resistance of the run winding.
Im building a electric bike, and i have a question about the rotation of the motor. I've built my diy bike, but the motors spinning the wrong direction. Its a permanant magnet 24v 350w motor. How can I reverse the direction of the motor? I have it hooked up to a 2 pin rocker switch and a 22.2v 1400mah battery and it all works, but how would i have to change it if i wanted to make it go the opposite direction? Its going clockwise now, but i want it to go counter clockwise. If i swap the connectors on the motor ( like connect positive motor wire to negative battery wire and negative motor wire to positive battery wire ), would that work?
What happens if a load, such as a light bulb, is connected to the start winding while the motor is running? Does this create a motor/generator? Very enlightening video BTW.
In theory yes, although I have never personally tried it with a single phase motor. But rotary phase converters work on the same principle and I have one of those.
Hands down this is the best video on TH-cam. No stupid music, perfectly clear explanations and real world examples. I have a whole house fan that I need to reverse and now I have 100% confidence in my ability to at least check if it is possible. I knew little about single phase motors before seeing this. Now I totally understand them. Thank you.
Even though I have a bachelor degree in Electrical Engineering and my profession is designing electronics, I found this video to be very interesting and informative. Thank you for taking the time to make it!
About reversing single phase induction motors, and how the starter circuit works.
woodgears.ca/motors/reversing.html
(and there are still a few induction motor topics left to cover!)
Matthias Wandel That is starting to make a LOT more sense now. I have two washing machine motors, one of which I hope to turn one into a table saw one day and wondered why they had a beefy capacitor on them. Keep the videos on this topic coming ;)
Matthias Wandel Another way to reverse a single phase motor: remove the capacitor, wind a string on the pulley in appropriate direction, pull hard on it to get it spinning and switch AC on shortly after. It will happily spin in the other direction but only by mechanical start.
themaconeau Cause turning washing machine drum need alot more juice than blade maybe?
Wayne Johnson Probably. But potential can be wound back. The first step is to get the motor moving correctly. Then I'll worry about ratios and torque later ;)
themaconeau would a washing machine motor have enough speed to make a good table saw??
This is why I like your videos, Matthias. You can explain things that I have little knowledge about in terms that make it easier to understand. Now, can you make a video about women, please?
People who really know their stuff can explain it simply. Those who don't teach in the school system.
The actual quote you want is "Those how CAN, DO. Those who UNDRSTAND, TEACH."@@lenyfreeman3807
@@weedmanwestvancouverbc9266 still incorrect... “Those who CAN, do; those who CAN’T teach!”
I just bought a 3/4 horse induction motor today at a second hand store. The plate didn't say anything about reversing motor, but now I know what to look for. Thanks!
Excellent video... I'm a Certified Electronics Technician (CET) so I have a good understanding of electronics... but never really "got" how the motor reversing worked... your video was very clear and easy to follow. Thanks! (I'm passing it along to be used in some training classes,)
VERY TO THE POINT, SIMPLISTICALLY BLOCK DIAGRAM PRESENTED ! BRAVO MATE !!! A SIMPLE EXPLANATION , OF A VERY TECHNICALLY COMBINED PROCEDURES FOR REVERSING DIRECTION OF A SINGLE & 3 PHASE MOTOR WIRING, AGAIN SPELLED/OUT SO VERY EASY TO UNDERSTAND THE IF/THAN. A TECHNICAL PROCEDURE-VERY WELL COMPACTED VIDEO, COVERING ALL THE MAIN CAN & CAN'T DOs' . IT IS SO WELL PRESENTED WITH A "HANDS-ON SIMPLISTIC ILLUSTRATION !
AGAIN, BRAVO ! I HAVE SEEN ALL YOUR VIDEOS & COULD NOT DISAGREE ON ANY OF THEM !. IT IS AN ART TO PRESENTING SOMETHING TECHNICAL IN A EASY-PEEZY TO UNDERSTAND PRESENTATION !👊👊💥🎯
Great explanation of the why! I have known the how for 40 years but have never known the why. Thanks for that. It never ceases to amaze me how giant corporations will step over a dollar to save a dime. It would cost next to nothing to add 1 wire pigtail to that motor and make it exactly twice as useful having a dual rotation. I really enjoy all of your videos.
Matthias, I was able to reverse my non-reversible motor (an A.O. Smith, 1/8 horse power) without altering the coils. I simply pulled off the casing ends and flipped the rotor end-for-end. After this, the motor ran in the opposite direction. It may not be possible to do this with all non-reversing motors, but on this one it worked perfectly! The motor powered a heavy-duty orbital buffer that shook so violently that it was nearly impossible to use. I disassembled it, removing the orbital counterweight unit and bolted the buffer disc holder directly to the motor shaft. I thought I had to reverse the motor, which it turned out that I did not have to do, however, curiosity got the better of me and I had to test my theory: that I could just turn the rotor end-for-end to get reverse rotation. It works and was easy to do on this motor. Thanks for your educational videos! Will
Great explanation! The thin wire used for the start winding is also to help changing the phase angle due to the greater resistance.
Perfect explanation of the exact puzzle we've been struggling with at my work. Can't wait to get to work in the morning and share with the guys. Thank you Matthias!
Considering myself highly interested in all kinds of technical stuff, I had to live 67 years until getting such clear explanations. You are a genius AND very gifted teacher! Thanks!
Exciting info and very well explained! Happened to reverse a motor yesterday, was debating if I should make a video....glad I didn't!
I rewatch your videos on motors every once in a while and I take in a little bit more each time.
Good stuff to know, I sometimes find myself repairing swamp coolers and air conditioners, and these videos have helped me out with it twice now.
Thank you for taking time to explain these kinds of things. I like your simple drawings and explanations and the bridging of the gap between the diagram and the physical item. It really fills in the pieces of the puzzle nicely.
As a refrigeration/hvac mechanic I havent had to get this deep in to motors since my trade school days. I still do love hearing about the theoretical side of things. Thanks for the great video!
I really like seeing these sorts of videos from you. Its very interesting to see simplified in such a way. With so many people posting novice DIY videos, this is refreshing.
I had the situation at 7:45 with an unmarked motor where I had to disconnect all of the wires, ohm them to see which ones were which and then I was able to confidently unsolder and resolver the switchover, close it back up and low and behold, it worked!
Thanks Matthias!
the analogy of the pendulum to the importance of the starting winding is absolutely fantastic...
OMG!!!... You've just explained so much in such a short amount of time in three videos, why can't schools do this? I always got the DC bit, forward/reverse/speed, 3 phase I'll never use domestically, so not a big deal, but at least I understand the theory now, but it was always single phase AC motors I didn't quite get because of the way AC alternates, I 'assumed' the AC capacitor was there for a 'kick' but had never bothered to go any further into it because I didn't think I'd ever understand it, but Woohoo!!!... Single phase AC, swapping the capacitor round, changes the rotation, so simple!!!... Why did they never bother to tell me that at school!... A video is worth a entire book!!!... Thank you!!!
Finally, a woodworking use for an oscilloscope! I knew there had to be an application, and if anyone would find it, it would be you. Another great and informative video - thanks Matthias.
this worked for my rc helicopter. it's very appreciated that people are so willing to share such pertinent information to fix some things. Thank you for making this video
This video showed me exactly what I needed to reverse a single phase motor on one of my shop tools. Thank you very much for this, it was a huge help!
you have a lot of induction motors... I think you've been collecting them for more than a few years!!!
Great explanation. Especially about why some motors are labelled as non-reversible.
Thanks so much for the video! I just converted my "non-reversible" drill press motor with a DPDT switch to reverse. No more backing taps out by hand.
I want to thank you for teaching me how to reverse old electric motors.
I finally got around to put in a reversing switch on my drill press.
You explain the process a lot better than other people who tell us how to reverse drill press motors.
My 1937 Delta drill press with a Westinghouse motor was easier than I expected. Once I open the cover on the motor there's only two terminals where the power wires went in and other wires came off of the windings and I just reverse those two wires that went into the windings to make it run backwards.
I put a four gang box on the drill press with three switches, one for the motor, one for the light, and a 4 way wall switch to reverse the motor.
My old drill press lacks a few features I wish it had but it was fun putting this feature on it. Now I just need to find a light for it that looks vintage.
Awesome video. I had been looking for a few hours and everyone had different solutions on how to reversing a split phase motor. You explained in one minute what others tried to explain in confusing and possibly incorrect ways.
Worked beautifully, thanks.
The way you can clarify things is brilliant! You'd make a hell of a teacher!!!
Very Informative and explained in very clear terms. You present the information at just the right speed keeping my complete attention. Cant stand people who speak way too slow wasting time.
Very interesting and perfectly explained. It rekindled my interest in understanding how things work and the underlying principles that govern . It sort of got my starting circuit going! Didn't miss the fact that you used the word condenser on one occasion. Endearing to anyone of my generation.
Thank you. Great video!
Very good explanation. The only thing I disagree with is the comment that the motor at around the 8:30 mark "has to have the coils removed from the motor case or a hole drilled in the case" , to get at the coils common point so it can be split and swapped. As they have to be accessible for the coils to be joined, the common points on these motors are usually buried just under the first layer of coils near the ends of the motor. With a bit of care the wires can be traced back, dug out and split. The process is similar to digging out the common point for 3 phase motors so they can be converted from Y to ∆ connection. I have reversed a number of these motors and always found the common point close to the surface of the coils. I agree that this level of modification is probably beyond a DIY level.
Well after watching your video,I needed a piller drill motor reversed,
So with help in identifing the starter windings I went a head and went for gold.And YES " YES" It had worked after watching hundreads of videos l still could not work it out,befor watching your stuff.
So Thank you for putting this vid up it certainly help me today,
This is awesome... you make it easy to understand. Did not understand 3 phase before from reading the books. Like 90 or 120 degrees out of phase for 3 phase power. Great Job!
This is exactly what I needed to know and nothing else. I love the hand drawn illustrations! Awesome work and I hope to see more like this.
That's the first time I actually understood the explanation on the start/run windings and circuit of an induction AC motor. Thank you !
Very much appreciate your explanation! I’m a self taught electrician (TH-cam Electrician’ videos ) and have been having a hard time with changing the direction of the motor I need to put on my table saw .
Good. I knew all that. I'm heading out to look at a table saw which I'm told two other guys tried and failed to reverse the direction. No history but I am guessing someone bought the wrong motor. It's got two new capacitors. Lol. Your awesome and clear is a great brush up and will save time and make me look like i know what im doing. Thanks. Rich
Great presentation. I really like how you explain the concepts and accompany that with the disassembled motors and even the oscilloscope. That made it very easy to follow.
Matthias - Thanks for a great video and excellent explanations too. I have been reading some of the comments. Interestingly ALL the comments are sensible and appropriate. Very often when someone does a good video, people spoil it with their irrelevant and irreverent comments which is annoying. Kudos to you, and keep up your good work.
At about 9:08 I think you read the motor wrong. I believe the label states Clockwise rather then counter clockwise. I might be confusing some thing though. Really like the video because of the explanation and demonstrations the combo of simple words and simple visuals are a great touch! Matthias you are a great teacher, woodworker, engineer, and many more thanks for your videos
I like your video and your diagrams and explanations very much. They are very informative and probably the best I've seen on youtube.
I even checked the videos on reversing a drill press motor cuz apparently some people like to reverse those for special purposes. My dad even put a reversing switch on his bench grinder back in the 40s or 50s.
Really interesting. And I agree with below comments. Keep this topic going.
I am just coming to understand AC motor and alternator theory of operation. I gain a basic understanding of what is actually happening, when I watch videos such as this, but I don't know enough to have the gut intuition that I have gained with internal combustion engines, which I began learning about as a young boy.
I recently bought an older Lima Electric 8KW 12 wire brushless alternator, and since I knew nothing about it, I began to research. The more I found, the more I thought to myself, "Wow, this is amazing!"
i'm so grateful someone is sharing this kind of information on the internet!
This is a great video and you’re the first person I’ve heard who’s gotten this right!!
So the start winding will likely have higher resistance than the run winding. In fact, the start winding will likely measure open as the start capacitor is charged by an ohmmeters DC potential.
That's one of the best overviews of how AC motors works I've seen. Thanks.
Thumbs up with the pendulum example. Note: you left out the other side of the coils in your first 2 diagrams, nice video.
How are you able to change the polarity of the winding when you are using alternating current?
Thank you dear... your way of explanation is just awesome... very easy to understand...
I enjoy your videos and they are very informative. Could it be that they don't want the motor reversed because instead of the starter switch arm dragging on the pressure collar that it would be pushing toward the pivot point like backing up a trailer behind a vehicle? Would that make it want to break off easier (maybe sooner than later)?
Very well explained. Quick Question? Some small motors, typically 1/4 hp, seem to work the same way, yet they have no capacitor at all. Thanks, Joel
Joel Watts See the linked article
You answered a question I had about my old GE reversible boat davit motors. One of them wont start so i have to give its large pulley a shove to get it going. I plan to first replace the start capacitor. If that doesnt fix it I'll assume its the connections to the start winding or the winding itself. Thanks!
Excellent video on AC motors...Helped me with wiring an HVAC motor for circulating air in an oven... Thank you.
Thanks This is the best electric motor video right now.
Wow, you sir make electrical concepts so easy. I take my hat off to you.
Thanks for the video, it was very helpful. I ordered a brand new motor for my tablesaw from grizzly and missed that the rotation was clockwise and I needed a counterclockwise motor.
It was not reversible, but I was able to isolate the start windings and switch the polarity.
Didn't expect to see an osciloscope in a woodworking shop :D, great video !
Ramekenas With the use of a homemade inductive pickup, oscilloscopes can be useful in the garage as well. (You really could see whats happening on the spark plug wires) Whats really cool now is that oscilloscopes that used to cost 5-15 thousand dollars (analog) a couple decades ago,can now be had for a couple hundred dollars or less on ebay and craigslist.
If you did more videos like this I would be just as happy as your amazing wood-working.
Love it, thanks. I could watch your videos all day
i thought u are genius in wood only... u are very versatile sir!
Effective teaching method, taking motors apart and experimenting with the way they work.
This video would make a good addition to the workshop physics playlist, right after the other motor videos.
Very well explained but i have a question i have an ac motor with 5 wires how can i reverse the direction ?
This is a really good video have had training on motors in college but it's been a while since I touched one and your video was a great refresher
Thank you so much for making this very informative and easy to understand (if you're versed in electronics) video.
I was looking to see if I could reverse the rotation on my drill press and found this video and it had every piece of information I was looking for. Thanks for taking the time to put it together.
I have a motor like this on my bandsaw. I want to replace the switch with a magnetic relay switch but the old switch only had one black and one white while I need the two black and two white to hold the magnet together during operation... do you have any experience with this? Where to find the other white and black wire? Thanks a lot. Love your videos.
Thanks for taking the time sir. Concise, informative, easy to follow.
I think I just fully understood induction motors for the first time. Thank you!
Matthias, love the explanation. I have a 3/4hp boat lift motor that only runs in one direction. It was full of mud daubers, cleaned thoroughly as I thought a switch might be stuck however still only one direction. From your video, I see that windings must be good as it wouldn't run in either direction if windings shorted. Any ideas I'd appreciate. Larry in Florida
You can reverse an AC motor like a pump motor. You just replace the capacitor to a reaktor which is used in fluorescent lamp circuits. And thats it! ;) It is very useful when we have just 3 wires out of the coils.
RoCCaT You could also reverse it if you have two phase power. Just run the starter winding off the opposite phase. But that's equally awkward.
Matthias Wandel Yeah you are true! There are a lot of ways to reverse. I heared about to use the reaktor and it worked well.
Great video, thanks. I've got a Tuscan 240v induction motor that appears to have 3 coils... there are 6 wires wires emanating from the coils, three colours red, yellow (joined) and green (to capacitor), then there are three black wires also? Any idea how this is set up?
Excellent explanations with practical examples. This is really great. Thank you.
Excellent explanation and diagrams. I loved the pendulum analogy!
A very nice , well explained and filmed and altogether useful video !
Exactly the kind of content I wanted. Fun and informative
Great explanation. I've learned a ton from your videos, woodworking and otherwise.
grate video!!! Now I understand a bit mor about AC motors!!!!
One question. On a single phase motor like the the first schematic that you show, If i wanted to be bidirectional I will Need a Neutral wire and two live wires to select the rotation right?
My question is, What happens if I accidentally activate bothe of the Live whires at the same time. meaning that both windings will be runing at the same phase? whill that create som sort os short circuit or burn the motor, or nothin will happen
Back to a video I've thumbs up'd in the past to try & understand a little more 😃
I have been doing research on making motors spin different directions and your video is the best! I have Car lift from Atlas that was purchased in US with single phase 230v motor and the motor is spinning in wrong direction. I had changed polarity according to the wiring diagram and it does the same. There are 2 metal strips that has to be changed from vertical to horizontal position and it should make it spin opposite, but it does not. Also swapping 2 positive leads did not do any different. I had another new replacement motor installed and it does the same. Atlas customer service representative suggested the motor winding being defective/installed wrong from the factory. Got new motor installed and it does the same. Any tips what could be wrong with it?
I always enjoy your videos.
Thanks for all of the work that you put into them.
watched the Video, with your help i could change the direction in less then 2 mintutes thanks from germany
Why so many dislikes? It was a very good explanation of how a motor works.
PS Love the "old school" scope. (I started with something similar) Cheers Matthias.
your videos help me relate whatever i've studied theoriticaly. Good work,keep it up!
Thats GREAT! I was waiting for this tutorial since the dust collector video!
One question: have u ever built a router jig for making wooden marbles?
Just got a 1 on my E&M AP exam, and it shows as I'm trying to follow this video...
Pretty cool Matthias. Over my head. Well done. Douglas
Hi, have an old bench grinder that ive taken to bits for refurbishing. Its a single phase, start and run type with a centrifugal switch, and does not have a capacitor. There are two wires coming from the windings; a switched (on/off) line, and the neutral, which were connected to the lead. Since taking the bench grinder to bits im not sure of the wires polarity, they are both black. Can I take a guess and connect ? Im thinking that if I get them the wrong way round it will reverse the direction of spin only, so easily remedied ! However I dont want to break something. Can I just connect and see which way the motor turns (50/50) chance of me getting it right, or is it not as simple as this ? Bear in mind this is a start/run type motor, Thanks if you can answer, I realise this is a dated vid.
Thanks!! Just flipped an old motor only using this video. I am fixing up an old Inca jointer:)
Thanks for the great video. I do get bored of the WW videos (No offence intended) but this is what I stay subscribed for.
Adam Harrington Glad you like it. The audience for woodworking videis thens to be much larger though.
It was woodworking that brought me here but I'm more interested in metalwork now. I recently reversed a motor by swapping two wires, before watching this I didn't know what I was doing exactly before this video. Could you explain how 4 (Or more) pole motors are wired in a video?
Excellent and clear explaination. High quality video.
hello mr Wandel, i have a single phase motor with 4 wires coming out of the motor. The windings are identical. one winding is connected by a capacitor(permanent). Can i just use the other winding and get it going by hand?
In this video, Matthias drops mad knowledge.
Basic physics to application, adjustment & building cheap, great video. Ind. Motor no start, but runs if rotated, check start cap,
I have a 1.5 hp ac single phase motor with a start capacitor and 4 wires coming out from the motor.
I figured out the leads that goes to the starting winding (checked which ones have continuity to the capacitor wires since the resistance was the same on the 2 windings).
If i switch the connections of the starting circuit, the motor just hums and does not turn. Is it because the centrifugal switch and the capacitor are not wired in series as mentionned in your text ? Is there something I can do to reverse the rotation ?
I have a Delta Rockwell 12 14 table saw. Is there an easy way to determine if the motor is 3 phase or not? I believe these saws originally were set up for 3 phase but I'm not positive the existing motor is original.
Hello! I have a 4 pole single phase with no terminals (all wires wrapped into the windings) possible to rewire to go in reverse? When I do switch up the wiring, motor hums until I spin the arbor (start capacitor not kicking things on) and the motor sounds a bit rough. Can’t figure it out :(
As you said, the start winding uses a thinner copper wire than the run winding. So if you throw an ohm meter across the windings the Start winding will be somewhere about twice the resistance of the run winding.
Im building a electric bike, and i have a question about the rotation of the motor. I've built my diy bike, but the motors spinning the wrong direction. Its a permanant magnet 24v 350w motor. How can I reverse the direction of the motor? I have it hooked up to a 2 pin rocker switch and a 22.2v 1400mah battery and it all works, but how would i have to change it if i wanted to make it go the opposite direction? Its going clockwise now, but i want it to go counter clockwise. If i swap the connectors on the motor ( like connect positive motor wire to negative battery wire and negative motor wire to positive battery wire ), would that work?
Good video, and good explanation. How about a reversing a pantorouter where the motor is stationary and the wood piece moves...?
What happens if a load, such as a light bulb, is connected to the start winding while the motor is running? Does this create a motor/generator? Very enlightening video BTW.
In theory yes, although I have never personally tried it with a single phase motor. But rotary phase converters work on the same principle and I have one of those.