HOW TO Test If The Motor Field Coil / Stator Is Damaged

When an electric motor is broken, one suspect is the fiel coild of the motor stator. In this video, we show different tests (balancing test, continuity "coil to stack" test) that can be completed to determine whether or not the problem with the motor is caused by the field coil being damaged or having failed. Note that those tests apply to motors (DC motors, universal motors, etc) that use a field coil based stator to generate the magnetic field inside the motor.
► DISCLAIMER
Always make sure you operate in a safe and secure manner.
For this project this means, make sure not to eletrocute yourself, even if you find it fancy
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► "Trouble" by Topher Mohr and Alex Elena
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═║║║╔╗║═╣╚╣╦║║║║║║║║║║╠╣║║║═
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[@SARSteam]

Simplistic video, to the point and absolutely awesome !! Thank you !!

[@TheLabOtomy]

Welcome

[@jotcw81]

OMG not only did this answer all my questions, but you used even the exact same multimeter and cleared all that up too :)))

[@TheLabOtomy]

We are on the same line Jaganath... not sure if that sounds like good news for you...

[@156dave]

I would use high resistance meter setting (20Mohm range) to check fields to lamination breakdown

[@luisricardolimachicalderon1071]

good edition of video man, coil rotating is amazing

[@behicbagaralioglu8293]

Most of the other videos start from the invention of motors and talk none sense rubbish this video hits the spot 👏 well done mate 👏

[@TheLabOtomy]

Thanks Behic

[@vextrek6036]

Excellent video. Thank you.

[@sarvjeetsharma3620]

VERY HELPFUL

[@TheLabOtomy]

Thanks for the feedback

[@pawemik7975]

Dziękuję bardzo, film mi pomógł!!!

[@siegfredvisitacion736]

Hello can you make a detailed video on how to rewind ac/dc motor e.g. from burnt motor to a running motor

[@aportandolealplaneta8970]

thank you teacher for your infinite wisdom blessings

[@biscayforex4317]

Best video I have found on this

[@TheLabOtomy]

Great taste!

[@michaelvargo7939]

great video! thanks for sharing!

[@TheLabOtomy]

Thanks for the support

[@colinevans7134]

Brilliant video, the best one I've seen, you showed and explained in all test results 👍👏💓

[@TheLabOtomy]

👏

[@zeberia1000]

I like this video because its Short and simple !!!!!

[@TheLabOtomy]

Thanks! (also keeping my reply short and simple)

[@retrorock3261]

Awesome tutorial...Saved Big Bucks on my 35 year old Sanborn air compressor with a Century motor... Unloader on Pressure Switch was sticking and caused motor to overheat kicking out thermal. After cleaning the points on the start switch also ran your test on the windings to confirm the over heating had not damaged them. Windings were discolored in areas but all confirmed ok, and although I suspect the life expectancy of the motor will be diminished due to the overheating, with my occasional home garage use, it should provide air for years to come. Thanks!

[@TheLabOtomy]

Nice! Thanks for sharing

[@adnanoguz7176]

Sehr schön, çok detaylı ve açık bir anlatımdı teşekkerler.❤

[@TheLabOtomy]

Beğenmene sevindim

[@asanterichard9498]

Very helpful, good job.

[@TheLabOtomy]

Gracias

[@asanterichard9498]

The LabOtomy Also I would like to know more about rewinding of motor can you please give me a link or ideas

[@markbruvelaitis957]

My conclusion: that jam tested A-ok. Also, very informative. Thx

[@Ernie616J]

When test field coils, should both coils be connected together? When I check ohms, it does not matter which leads I test, it seems the coild are connected together. Testing a Bosch 4000 table saw motor.

[@cosmicallyderived]

Just what I needed

[@TheLabOtomy]

Nice!

[@Tankaroonies]

Best thing to do that I have found is to test the current through each coil, let the current run through each coil at the rated voltage whilst monitoring, then you will find out if any insulation/enamel burnout/burnthrough has occurred. This was shown to me by a more experienced person than myself, a man of the age of 67 (great teacher). I will always remember him for this very important point; When I did this resistance test, he asked me what I was doing (in a nice way), I explained, he then taught me that you CAN'T test an insulated winding with a low voltage meter. The voltage a meter produces will never jump the gap in a higher voltage winding, you MUST use the voltage the winding is rated for to test it. I hope he doesn't read this but I after a few years of working with motor windings, it has now turned out, that he is correct.

[@irishguy200007]

On a starter motor, could one connect battery directly through field windings to check if a magnetic field is developed or would it draw too much power?

[@Tankaroonies]

?@@tttttttt8482

[@Tankaroonies]

Measure current as you increase the voltage, also remember that the shaft and chassis must be low resistance through bearings on the wee squirrel...@@tttttttt8482

[@luckynoob3328]

I think it should be ok since it's just a continuity test

[@Tankaroonies]

multimeter on current setting.@@tttttttt8482

[@unobianconero5751]

if the hi rpm of motor is working but low rpm have sparkle in starting, can we use just high rpm only or it should be replaced with all new winding? can we replace just low rpm winding? what is the name of those small parts like arcs? are they coils? I don't know if they are burnt or what, because the motor is too old and one of those I said got black (like dirt oils or something) but when we scratch it it's like copper underneath, so is it bad? or just needs to clean up?

[@rocktruckrob]

Good to know...thanks for sharing....cheers be safe be kind

[@TheLabOtomy]

Will try ;)

[@mickeyyoung8442]

rocktruckrob me

[@randykarelly7230]

Great and so helpful to knowledge..

[@joekotze2781]

Good day. Thanks for the great vid. In my case one of the coil wires indicates continuity to my stack. How do i fix it ? Please help

[@jaileal8806]

You have a short circuit. If you have time and expertise you could consider trying to repair it but it can be fairly challenging. Depending on the size of your motor and replacement costs it may be better to have it replaced

[@wolnyizrownowazony4605]

Siema, mam makita gr 2470 , która z dnia na poluzowała się śruba od stojana przez co styk się przypalił ale mimo wyczyszczenia nadal nie dział. Pytanie bo pomierzyłem jak Ty wirnik i wartości przy 180 ° to 1.0 gdzieniegdzie 1.1, obok siebie na komutatorze 4.6 z obudową 0.0 a stojan w 3.8 , 3.7 a z obudową 0. Powiedz mi czy takie wartości są ok??

[@colinevans7134]

Best video I've seen on this

[@TheLabOtomy]

Thanks Colin, appreciated

[@Utking3]

Love the music :)

[@user-xm8cu4kl5r]

Спасибо за информацию

[@herbertnkusangombe1815]

hie my motor reads 2.4 on the 2 coils and 3.0 on the one, its a 3phase, can i still use it and there is no earth lik

[@omaradan8062]

Thanks Nice Idea

[@TheLabOtomy]

Welcome

[@user-kp8ns2ch9s]

Very good video friend. I have external running coils: 1 entrance, 3 pairs connected exit-exit, entrance-entrance, exit-exit and 1 entrance as terminal. The same with starting internal coils. I use 0.42mm (27 AWG) copper wire with 90 turns for each coil and resistance 3 Ohms = 12 Ohms from entrance to terminal. Is 27 AWG of copper wire correct for Ampere? Thanks

[@josephquidlat5072]

Good day! My Friend ,what is the main Reason you Set in 20O Ohms rathers than higher 2,000 Ohms? The stator you test it is 110V or 220V? Thanks for your Response .

[@lvd2001]

My motor has 3 wire come out (starting and running cap electric motor single phase) - white, black and blue ? Not Red and Blus - like yours... So which pair of wires do I measure?

[@vanhetgoor]

The colours may vary. Every manufacturer can use the wire he likes or what is available. I have a motor with two black wires and no condensator for starting or running, only one for the reduction radio disturbance. Think for yourself what the use of the wire is and then measure accordingly. In the future all wires will be black, because only black wires matter.

[@hariomkarankandere1662]

Thanks sir

[@kanegeorge5581]

I’m trying to figure out what is wrong with the brush gear motor on my vacuum cleaner because it won’t spin. I took out the motor which is connected to the PCB board with a white and black wire. My resistance measures at at 9.6 and the continuity test passed. Do you think that the issue may be with the controller board for the motor?

[@vanhetgoor]

With an ordinary multi-meter you can measure the resistance but not the capacity or the reactance. Neither a condensator can be measured for its capacity, nor an electric coil can be measured for its capability to produce an magnetic field. A multi-meter can only measure the conductance of wire. If half the coil has a short circuit, then you still can measure some continuity, but there will be hardy a useful magnetic filed. The result is going to be that the vacuum cleaner is not functioning as he should. The motor is running and making sound. It is like watching "The Voice of < fill in the name of your country >" Alotta noise, but nothing useful.

[@sarvjeetsharma3620]

THANK YOU

[@TheLabOtomy]

Happy it helped

[@user-vl2rp7gj9v]

جيد شكرا

[@mustafaadan5012]

Thanks that's amazing video channel I like it Nice I dea

[@gabrielquezadagallegos8266]

Cuales cables van a la red de alumbrado? Ahí aparecen 4

[@japs7312]

Superb video, straight to the point and easy to understand. It help me very much :)

[@TheLabOtomy]

Thanks for the feedback

[@hvacae6904]

How you will know if the coil is grounded if the ohmeter setting is on lowest it will still show open even if its grounded it depends on individual to decide

[@Loukham]

I have one has black colour what has do it?

[@user001sg9]

Very informative video, thanks. I am not sure what exactly is meant by "input" and "output* pairs of field coils. A coil has a beginning and an end terminal. What would here be the "input terminals" and what would the "output terminals" of one single field coil? Could you kindly explain, please? Thanks a lot in advance.

[@TheLabOtomy]

Hey user001sg9, good catch, looking at the video today (it was 6 years ago), I'm not sure why I called it input / output terminals knowing it is running on alternative current. In any cases, the test is just about testing from one end of the coil to the other end to make sure there is continuity and confirming there is a balanced circuit resistance between coils.

[@DavidTorres-kl2rt]

nice video

[@tttttttt8482]

Can this test be made using just an electric lamp like 100 w ?

[@bilgaissa5831]

I have small av motor with 5 wires and between 3 of them i see 1 (no continuity ) is that means motor is defective

[@Shogunlanun]

Nice content..done sub

[@ademline2010]

Hello there. I had one drill, its stator was burnt out. I cut the coils on the pillow stator with a side cutter, I counted 250 turns. I rewound with the same diameter coil, but the stator gets very hot while the machine is running. Where did I go wrong? By the way, I did not apply varnish with the bobbin. I would be glad if you help. Each winding of the stator is 9 ohms.

[@Tankaroonies]

Good luck with that mate and coodos for trying; a 3 phase motor is wound accurately by machines and wound by people in the old days, you can try and match the other original windings but they will NEVER match; but if you repair one of the windings yourself, the magnetic flux induced in by the action of the motor will be different, the differences in the magnetic field will induce a different current on the stator winding you wound, maybe drawing more current from the winding you made, can be less to depending on the manual winding..

[@chocholatemilkshake4799]

0:15 you got my subscribe mate

[@omelectric9670]

Thanks

[@TheLabOtomy]

Welcome

[@antonbende8210]

No BS... ! good ! thx.

[@TheLabOtomy]

Good comment, to the point, thx!

[@adrianmoroianu9118]

Hi.....in an one phase motor the coils have to have the same measurements?

[@jamesandonian7829]

Each phase should have identical resistance so yes

[@tomk3732]

Yes except start coil.

[@mathematiquesinformatique1423]

merci

[@engineert.r.t1983]

Nice video

[@TheLabOtomy]

Thanks

[@user-yt1td7qo4q]

What happens if you confuse the polarity of one of the stator windings? Что произойдет, если перепутать полярность одной из обмоток статора?

[@TheLabOtomy]

We measure resistance, and the stator winding is just 1 long piece of wire so does not mind polarity for that test...

[@user-yt1td7qo4q]

@@TheLabOtomy I mean, if you apply alternating voltage to the engine.

[@user-ps9pb7zo2z]

awesome

[@mohalmisri1230]

Very nice,I have a question,small toy motors I don't see those 4 in and out wires for the coil,only the rotating axe rotor

[@TheLabOtomy]

There are dozens of different motor design, this video focuses on one of the most common types found in many DIY / household equipment. Steppers motors, induction motors, etc look completely different in their design. Only 2 wires could indicate use of a permanent magnet in place of a coil and yet another type: PMDC motors

[@mohalmisri1230]

@@TheLabOtomy nice so two wires will do for the test ,one for in current and the other for the out current

[@TheLabOtomy]

@@mohalmisri1230 Correct

[@shreifsalah5223]

lovely music this time . I will enjoy the music and care about the information later

[@TheLabOtomy]

Works for me! Thanks for the feedback

[@marcelsimon6425]

Isolation is measured at the highest possible resistance range AND at least at motorvoltage

[@amokranetacine3806]

Magnifique

[@somapalakarunanamage3796]

i m completely new to this field but trying to understand. how do you decide in the gauge of copper wire znd number of turns. can u hand wind it?

[@TheLabOtomy]

Number of turns but also winding patterns will determine the electromagnetic force applied. This is a complete field of study of electrical engineering, so leave that to the specialist (same for rewinding, specialized shop can do it ensuring motor performances remain optimal)

[@somapalakarunanamage3796]

thanks

[@jnkmal9519]

"Trouble" by Topher Mohr and Alex Elena = good jam :)

[@TheLabOtomy]

For sure

[@AmatorElektronik]

A gdyby zwarły się 2 zwoje ? 2,8 ohma i np 2,78 ohma ? Ta metoda nie wykryje zwarcia międzyzwojowego.

[@otepquidlat770]

My Friend Good day! My Lowest Setting Of my Multitester is 600-Ohms it's Ok & It can Measure Accurately ? Please help Thanks & More power .

[@TheLabOtomy]

Give it a try and check if you can spot any variations

[@otepquidlat770]

@@TheLabOtomy ,Thanks for the Advice.

[@coronacofit9131]

Good good

[@enriquehuryk2480]

Por qué las etiquetas en inglés? es incómodo entender rápido los pasos, hay que saber de antemano los pasos de lo que se mide.

[@kousthubasheshappa8983]

Congrats for illuminating explanation. Accordingly,Please clarify the following about motor winding of mixer grinder: 1.If resistance value between neutral wire and motor windings:speed1.2.3 *showing infinity/ OL(1)* (N-Sp1,N-Spd2, N-Spd3) Then,What is the reason for infinity value/1??,when measured between N-Sp1,N-Spd2, N-Spd3. 2.But, Motor winding resistance values between Sp1 & spd2 winding : 5 ohms , between spd2 to spd3: 1.8 ohms between spd1 to spd3: 0.8 ohms 3. Resistance between Motor windings & motor body is infinity/1 # So Please guide us how to troubleshoot the problem *as mixer grinder NOT running at present* Note: Power supply continuity signal is OK/ Normal,from socket up to Rotary switch.

[@osmarmartins8765]

Gostaria que fosse em português

[@hapetaa]

how to find broken winding wire end on stator?

[@robertmorin6495]

Difficult to do because the windings have fine insulation on the wire. You would have to unwrap or unfurl the whole winding to a straight line piece, scratch the insulation off the wire with a razor blade, test with an ohm meter every foot or so and if not found repeat the scratch and ohm meter test again and again until found.

[@northwinds9155]

check if shorted... instead of continuity though you are expecting the reading to be 1 not 0

[@juanmarcelovaldiviezo3467]

El anuncio esta en español Pero todo el video en ingles .parece muy interesante pero no pude entender nada 🤨

[@mipani]

Para mí el anuncio está en alemán (soy alemán). Los traducciones de anuncios probablemente ocurren automáticamente. Veo eso a menudo.

[@olo1299]

Poza przebicie do karkasa zwarcia między sąsiednim zwojami nie sprawdzisz takim miernikiem. Bardzo uszkodzone stojan jak najbardziej przetestuję ale trafiają się nieraz takie gdzie zwarcie jest miedzy sąsiednim zwojami. Na takim mierniku tego nie zobaczysz a po podłączeniu do prądu ewidentnie widać jak jedna ze szczotek nieznacznie bardziej iskrzy. Niezbędny do tego jest miernik niskich rezystancji. W 90procentach uszkodzenie stojana da się sprawdzic amperomierzami potrzebujemy 2 i do każdej z cewek podłączamy po jednym. Od razu widać na której cewce co siedzieje. Najlepsze do tego celu są zwykle wskazowkowe. Robię masę takiego sprzętu dziennie i wiem jedno. Proste sposoby są najlepsze. A Gdy zrobi się już tego trochę to wsumie na oko widać o gdzie jest awaria

[@tttttttt8482]

Привет. Какой недорогой тестер низкого сопротивления порекомендуешь ? , Подойдёт ли мультиметр ? Расскажи детальнее как проверить статор на межвитковое замыкание

[@mustaphaboucheta3950]

Formidable

[@iraqresitance9663]

From iraq my greeting

[@TheLabOtomy]

Nice, greetings back my friend

[@juanabreu5127]

If one turn of a coil is shorted, test 1 will not show it and the stator won't work. A third test must be carried out to detect that kind of failure.

[@TheLabOtomy]

Hm... will need to check about that, thanks for the feedback

[@izzzzzz6]

is 0.3 ohms per side too low?

[@TheLabOtomy]

There is no standard value, it all depends on the motor specs, wire gauge, number of turns, etc only the motor specs datasheet (if it is available) can confirm this

[@gabrielquezadagallegos8266]

Se entiende que si se explica cómo reparar un aparato malo es para todo público. Todos no sabemos y queremos aprender .Por lo tanto den mayor informe. Con más detalles

[@eugenenault4935]

Is this a music or a educational video?

[@TheLabOtomy]

It's a DIY concert

[@markman63]

I have only 3 wires coming out of my motor

[@ghostridergr8259]

thw second test you make...you must put set the tool on the top level of ω.. 100MΩ

[@robertmorin6495]

No, that's not needed for a continuity test. Any short between either winding and the stack would cause the meter to beep or show continuity (zero resistance) just like the end to end test. And if this was the case the stator would need to be replaced.

[@ctjohndeere]

SHOP VAC. motor 6 months old. multimeter tested armature, field coil, brushes good. motor inop. What's up with this?

[@TheLabOtomy]

Wiring checked? Ball bearings? Decoupling capacitor

[@ctjohndeere]

checked and double checked

[@lotar0078lotar0078]

Quiten la música

[@jalalalaee9580]

I didn’t get it,

[@jonathanwilliams6055]

] would 2 c the vidoe

[@sershetech5584]

😮👍👍👌 watching sub bro

[@TheLabOtomy]

Appreciate it

[@giuseppeortino4186]

In italiano no vero?....

[@danielpirela2391]

para leer busco un libro no un video... entiende un audio visual es didáctico lúdico pero nunca ruidoso y estridente si no lo entiendes no importa solo paso la pagina y listo

[@makita_service2794]

И как вам нравится это видео? Ремонт Makita DDF458... kzbin.info/www/bejne/m32loKKshcSEgNE

[@GerardoZuniga]

This is the MUTE guy 😂😂😂😂

[@TheLabOtomy]

...

[@jpillstream]

3:48 minutes with porn music

[@corrydriscoll6920]

*FUNK

[@danielpirela2391]

si quisiera oir musica no visitara este sitio, acaso eres mudo ???? esto es perder el tiempo

[@TheLabOtomy]

Aparentemente no puedes leer ... ¿Entonces quién es mudo?

[@justincase8532]

Holy Bejeesus the music is awful.

[@TheLabOtomy]

Hallelujah!

[@briankscott06]

Too bad you didn’t get the memo about adding stupid music to your videos, I’d of given you a thumbs up had you left the music out!

[@TheLabOtomy]

Too bad you did not get the memo about me not caring about thumbs up...

[@MatyasArby]

@@TheLabOtomy LOL, I liked the music, felt like I was watching Knight Rider!

[@nawazshaikh2671]

Thanks

[@TheLabOtomy]

Welcome