I spent my working life in electric motor repair.Our main work was for the Lift industry,OTIS,SCHINDLER etc on DC gearless motors and Generators,but we repaired all types of motors from fractional HP to 6 Ton pump motors. Our shop was in East London England and started in 1919.
whoever the gentleman that is the winding tech ... you can see in his face and actions that he actually cares about what he is doing... industry could use more professionals like this man! :)
Back in the 60's I worked in HVAC. Rebuilds were cheaper and better motors than new factory because higher quality components were used such as bearings, coated wire, and precision balancing. Small rebuilders staked their reputations on the quality of their rebuilds.
I used to rewind a different types of electrical motors many years ago , I really enjoyed all the procedures and the testings. Thank you for posting this video.
I was a rewinder in Australia. had a megger meter to test for earth leaks, and a prufrex to test for short circuits in the windings. as above used to heat up the stators so the coils and insulation would come out easier. As an apprentice the single phase coils were wound on nails in a piece of wood. 3 phase we had a piece of wood cut to the shape of the coils, only would 1 coil at a time, so 48 slots and 48 coils took a while. unpowered winder was hand cranked. after all the coils were inserted the coils were connected into groups. very tedious work. later years had to metal plates with rows of holes all over them they were bolted onto the winder with a spacer between. put paper tape on the outer side with holes put through the tape to show where the pins had to go. had a varnish tub to dunk the windings. alot of what I did I saw in the video but their clean up is better, better to work on a clean stator. had a winter with 52 frosts in a row got lots of water pump motors to repair. for coils had some U shaped formers in varing sizes they had a wide part where the winding went on and a thin backing on one side and a slot up the middle of each the width was about 1 inch on the first and 2.5 inches on the biggest there was7 sizes. used them for lots of small motors. the coils were long with round ends very easy to use. could have a Davey 1.5 hp 2 pole in the oven from starting the first coil in 20 minutes. to old to do that now.
THAT company is doing a great job of repairing that motor. Rewinding is the hardest job to my belief. You have to be careful not to damage the enamel insulation of the wires; a job of great patients! And you have to connect the wires in a certain, precise way, otherwise you have a rotor that doesn't turn the correct way or not turn at all, or burns up the coils and trips the breakers/fuses. Job well done Global Electronic Services!
@Charlie K Low Voltage (parallel) 220 230 240v L1=1&7, L2=2&8, L3=3&9, (4,5,6 tied). High voltage (series) 440 460 480v L1=1 L2=2 L3=3 tie 4&7, 5&8, 6&9 (36 slot 4 pole 3 coils per group 1750 rpm (1800 theoretically) 3 phase wye wound motor 9 leads out). What’s your definition of competent?
watch a lot of amateur recoil process on youtube, this is the most professional motor recoil process that I seem. Have to admit that we should let the right guy to do the job.
I did 10 years as a motor rewinder straight from school as a 17yo . That was 32 years ago and I still think I could pick it up again within a few days, it's a unique skillset for sure ☺
I’ve worked in this industry for 25 years. In some cases small motors are replace unless the motor is not available off the shelf! Larger rewinds are normally more cost effective over replacing unless the motor is in bad mechanical shape or has core damage causing heat losses in the stator or rotor core.
Hello. Thank you for watching the video! While the process is tedious for sure, we have many technicians who specialize in the rewind process and have it down to a fine art! Repair/rebuild/rewind are definitely great options to get a motor back up and into production!!
Hi guys, I'm so amazed to see this entire process mostly automated and standardized as I only see my dad doing this manually from start to finish. On this note, I wanted to invest money and take his business in the next level. Care to share where we can source all the equipments you are using at your workshop? By the way, my dad's workshop is in the Philippines. Would really appreciate if you can share the information I am after. Thanks!
Really fascinating. I would love to work there as I would learn so much and I like the room they have. Plenty of space for everything and it’s really clean especially considering it’s such a dirty process.
Great to see you here! I've come across your channel in the last couple weeks doing motor research. What are the odds I'd see your comment on a video? Keep up the content creation! 😎
Years ago, when in tech. college, we didn't have burn-off ovens. We did that procedure by setting some firewood alight, and putting the stator in it, then we manually clipped the windings out. Of course, the largest motor donated to the school was about 1 HP. We learned to wind the coils by hand, not having a winder. Line the slots with fish paper, hand wind, pack with sticks, then lace it up. That was hard on the knuckles, on the small 1/2 HP motors. Coil shorts were found by a growler.
Did my apprenticeship doing this work . Such a niche trade .. one thing didnt like the balance weight location . Epoxy can flick of from there . Usually tuck it under or use the round alloy spigots to place washers on ( then burr the alloy spigot over ) . Def share this video with my friends and family to show them the trade I once did . Thanks for the video . Nice clean workshop too .
It really worth repairing especially many motor are special designed and you cannot buy a new one in short time. And those special designed motors are very expensive.
Does rewinding an electric motor save a lot of money compared to buying a new motor? Who knows the answer please? A very useful video . Thank you very much . I wish you lasting success .
I've had many alternators (almost the same as a motor) rebuilt for like $30-$50 with a one yr.guarantee, and new would be like $150 - $200. They were as good as new.
The only thing missing is an air gap voltage test, to make sure stator laminates aren't shorted. I've seen cases, where hot spots occur because of inter laminate shorting. That spot glows red, than that heat telegraphs to the windings, and causes shorts by localized burning of the insulation. That test can and should be made with no windings in the stator whatsoever. It can be performed by a coil with alternating current, or by spinning a permanent magnet rotor in the stator, driven by an external motor. A quick peak through a FLIR camera could tell you weather or not that stator armature is worth rewinding. High eddy currents, at the very least, make a motor inefficient. at worst, a future failure. The oscilloscope can give clues, but you can't tell if it's an anomaly in the windings, or weather it's actually the stator armature. You would have to rewind the motor, and check for asymmetry. Even then, it's still unclear weather there is an error in the windings or again, the stator armature.
I do this for a living, it's not my dream job lol, and the winder should use feeders on those slots, less chance of damaging the insulation on the wire, oh ill let him off he started using them :)
Same here. I don't lay coils from the end l wrap my arms around and put them in the bore. Dont use phase heads either, use individual groups, personal preference.
I was a foreman in a winding shop in çolchester essex some forty years ago and I still remember doing all the connections our motors were for all sizes of fans. Derek Warren somerset
When inserting coils you should use a insulation to prevent the coils from getting scratched. Also the coils not yet inserted should have a layer of protection. It's good to cuff the slot insulation. Rear stator laceing not good. Well equipt workshop
Hi, i am hoping you might be able to assist me. I have a brushless electric motor that hums but does not turn(belongs to a phase 1 bench grinder). When i tried to turn it by hand in the "on" position, it does not move. While in the "off" position, it turns just fine. I checked the capacitor and it works fine. The bearings are good too. Any ideas on what might be wrong with it?
Do you ever need to put the rotor on a lathe to correct its concentricity? I heard somewhere that this is standard practice for servicing aviation motors.
6:05 why prevent the coils from touching the core if the wire has insulation already? I know, every motor has these paper pieces to protect the windings from getting scratched if any pull occurs, but really - if the windings are already insulated, then why isolate them from the core?
i am all for the correct motor or generator repair ... however, what is the repair cost compared to a new motor or generator with new everything? thanks....:~]
