How to Diagnose and Repair a Capacitor Start Motor
HTML-код
- Опубликовано: 28 июн 2019
- How to diagnose and repair the capacitor on a capacitor start motor.
Multimeter for testing capacitor: amzn.to/2YrV49J
SOATMON Blog page: www.Soatmon.com
SOATMON Amazon Page: www.amazon.com/shop/soatmon 
Хобби
This was a great video. Helped me understand why my fan motor wasn't working. Thank you!
You're welcome!
I just came across this video and I think I will be able to fix my table saw. Thank you.
Awesome. Hope it works out for you!!
Thank you so much. Extremely helpful. 😊 👍
You're very welcome!
this video was what I was looking for. I am not experienced with electricity, and a fried said I can shock myself on the capacitors on the motor i want to fix (from my plate compactor).
I believe the "starter capacitor" is the problem on mine also, it hums, tries barely to spin or not and then breaker goes out after a few seconds.
Hope It goes well, and I remove them safely so I can (hopefully!) find and get new capacitor to try!
Thanks for the great video!
Very informative, Thank you.
You are welcome!
very useful, thanks!
You're welcome!
Great explanation
Glad you found it helpful. Thanks for letting me know!
Thank you for that sharing sir.
You're very welcome!
Great video!
Thanks!
Thanks for the video =)
My pleasure!
Sure do appreciate you presenting this one. It always was a mystery to me about those capacitors on the motors. Never realized it was something we could find and change. By the where did you go to find the replacement. Possibly you did say but my computer is acting up and the sound didn't come through on parts of the video. Have a good weekend and stay cool.
I usually get them on Amazon. Most of the time you can type in the number and get the exact same one. If not I would type the number into google and see what comes up. The original one was not a very robust capacitor so I changed to one that had the same specs. If the motor just hums, turns freely by hand and the brushes are good, this is usually the problem. I have changed a bunch of them on AC compressors over the years. I just bought the meter to check it and was glad to find it. In the past they were too expensive for me to buy. I used to just buy a new capacitor and see if it fixed it, now I can check it first. Good to talk to you Glenn.
I found mine with the same MFD range on E-Bay for $17.15 including tax and free shipping. I cleaned the burned contacts in the end-bell but the motor still wouldn't start under load so I knew it had to be the capacitor.
I love that I'm learning from a guy who seems to have lost part of his index finger.
Just the video I was looking for though. Thank you.
You're welcomed!
Used your link to get that voltage tester, it'll be here tomorrow. ( baldor industrial 2 HP compressor motor ) thanks!
I hope you get it fixed!
Awesome explanation , thank you.
You're welcome!
Thank you, very informative! Just pointing out that mFD means millifarad, which is 1000 times larger than one uF or microfarad, so 1 mF = 1000 uF.
Awesome! Glad to help!
They are the same. mFD is the older abbreviation.
Thank you. Super helpful.
You're welcome. Glad it was helpful!
By centrifical clutch you should have said centrifical starting switch. Most elec motors use a starter winding along with the starting capacitor to assist starting the motor. Once up to speed a pair of centrifical weights swing out and remove the starting coil from the circuit. You can hear them click on motor spin up and again as the motor winds down.
Yes, thank you for the correction. It's funny when you edit your own videos you hear what you think you said. Thanks for letting me know.
TY
You're welcome!
1:36 love that sound .........
Thanks!
1:12 (super loud hum) 15A AC GFCI Shorts Green Wire andThe White Wire Outlet Breaker: POP!
Nice video. At work a motor has same problem. They wanted to buy a new motor at $600.00! I told them let’s replace the capacitor first, only $55.00. Hope it works, I’ll earn some brownie points with owner if it does!🤣
I hope it worked out!!
Thank you for the video. Have a 6" joiner that has not been running and now I know why. Do you know if the supplied power to the unit will cause the capacitor to wear out faster. I'm wondering if the cable run to the shed and an extension cord to the joiner may be contributing to the failure? Thanks again for the video, I'm heading out to the shed to pull off the capacitor.
Hope you got it fixed. Sorry I don't know about the power effecting the capacitor. It can cause your motor to over heat though.
good stuff. I appreciate you posting this.
You're welcome Mike!
Hi,where did you get the capacitor? I have a Hilka/Wolf bench grinder,I have to spin the wheel then it starts,Is there an equivalent capacitor I could use,The one on the grinder is blue, Two terminal connectors,it reads 5 uf +- 5% ,we 350 .Ac 50 Hz .60 Hz .The grinder is 1/2 Hp 240 v 370W 50Hz 300 single phase.i don’t understand equivelant size capacitor I could use,I’ve looked on EBay but not one equivalent.Any advice would be grateful.Thanks
I have a Vevor 5hp 15amp motor and I just blew the capacitor on the right side as you're looking at the shaft. Is that the starter capacitor or the run capacitor? This is a new motor on an forging press. What causes them to blow? Thank you
Great video - simple and to the point. Thanks!
You're welcome! Thanks for taking the time to let me know.
Thanks, I didn't know about the 12% rule.
You're welcome.
One of my prongs is gone on my capacitor and the wire looks a little burnt. Do you have an idea as to why?
Does the polarity of the capacitors matter the way you connected the wires?
For film caps doesn't matter
I did this repair for my bandsaw motor and I can use it to cut wood now but I have to spin the pulley by hand to help the motor to start turning. Once it starts it stays at full speed and has good power. The old capacitor reads : motor starting capacitor cap 300 mfd and w.v 125 v.ac type 1287 Seika electric co The one I used to "fix" the motor is the only one I could find that was even close to the original it reads: ABS Motor starting Capacitor CAP 400 MFD W.V 250 V.AC Y759 YC Electric Co Do you know where I can buy the same size/ type capacitor as the one that came with the machine as stated above and do you think it will work better and the motor will start up normally? Thanks
the capacitor no matter the size for the moment , but if you replace the capacitor and the motor don't star in his won the switch is open ,check the switch for close circuit ( NC) when the motor is stop and unplug
Help! My Ryobi band saw wouldn't turn on without a spin on the wheel. I let it run until the motor smoked. I turned it off. Did I burn up the motor? I'm hoping I need a capacitor but I don't know where it is. I took the motor off but it looks sealed. How do I get it open?
Hey, I just got given a Metabo Dust collector, and I plugged it in and nothing. I even changed the plug, thinking maybe a fuse. But same. When I turn it on, I don't even get a hum. There's nothing, would you know how I could get this running?
Check with a multimeter to make sure you are getting power to the motor. If it's the capacitor it should hum when turned on. Sounds like you are not getting any power.
Good video, but the uf is actually a lower case mu, which is used to denote micro-farads (mfd)
Thanks!
I really hope the capacitor replacement will fix my problem.
the motor is not starting but it seems like it's trying, gets VERY hot, and then the fuse blows after few tries. I hope it's nothing worse than the bad capacitor.
thanks for such a great and useful tip video!
Good luck! I hope you get it fixed. Don't let it overheat, it will ruin the motor very quickly. If it don't start turning turn it off immediately.
@@SoatMon cheers man!
I hope I haven't toasted the motor yet.
Can bad capacitor blow a breaker
Does it matter how you reconnect the wires I notice they’re both the same color on mine and no indication that the wires need to be connected to a certain wire on the new cap
I'm using a 110Vac single phase vacuum pump, I've measured the capacitor and its reading matches its description.
The pump end has not much drag, I can spin with my hand easily.
And the motor coil is fine, it can work without too much current after its been warmed up? I think...
Its just the motor can't start properly in the first few tries. Any suggestions what should I check next?
If it has a starter capacitor it should have a clutch that will be engaged when starting and then disengage when the motor gets spinning faster. I would check to make sure the clutch is making contact when it's not spinning. Make sure the clutch is free moving and the springs are pulling it into contact and that the contacts are making an electrical connection. Once the motor starts and gets spinning the clutch has to disconnect and you should hear it click. Good luck!
Thanks mine is making the same noise and the capacitor is swollen from one side too
Sounds like that's your issue. I hope you get it fixed!
Hey.
I have a question.
My table saw starts up normal, but when I push the stop button, and de motor stands still a hear a ticking sound for about 5 seconds.. But when I pull the plug, the ticking stops right away.. Could this be the capacitator? Or is this something else?
Thanks in advance..
Dear Soat Mon, Our furnace (circa 1981 Borg Warner/Trane natural gas, still in good condition) blows the screw in breaker (locate on outside of it) whenever the blower tries to start. [Everything else (outside AirCond compressor/condenser) work fine]. With the motor electrically disconnected from the system, the start relay actuates, and fuse is not burned (& AC unit runs fine). It's only with the furnace blower motor connected that the fuse blows at start. ¿Is this motor bad or start cap, kindly? The blower assembly turns freely inside the plenum. I've measured the blower motor's run cap and it seems fine (reads 12 micro Farad/10 Micro Farad rating). I've changed the run cap with a new one, but am afraid of trying to run said blower motor for fear of blowing another ($6) fuse (screw in Edison type S). ANY advice or comments much appreciated. Thank you much. Thank you for your video.
When you are checking the capacitor with the multimeter is it set a ohms for resistance? Thanks
Neither. You need a meter that can check capacitors. I have one listed in the description of the video. Good luck!
Great video. If the centrifugal switch is not releasing would this cause for the motor to draw higher current. My motor runs approximately 3amp without load and about 4-6 amp with load. I have found when the switch is not opening the current jumps to 22amps. The problem was a dead capacitor which I feel was the cause from the centrifugal switch not releasing when motor on. I find that the switch only doesn't release when the load is on the motor soon as I put some load after turning the motor on and off eventually the switch doesn’t release and the current jumps higher. The switch looks clean and no damage. Any help to diagnose is appreciated. Cheers
Does the capacitor protect the motor from over voltage? E.g if I connected a 110V motor across a 220V supply, would a 125V rated capacitor give out before the motor is damaged?
It's not used for protection but to kick start the motor.
Is one of the capacitor lugs negative and the other a positive lug? Can I hook them up either way?
It depends on the capacitor. It should be marked if you have to hook it up a particular way.
Great video! I could really use your help!! Im having the exact same issue and I went and replaced the capacitor. It just blew up on me! I cant figure out what i did wrong? Do you have a contact I can reach you personally? Thx
Why is it that all the electricians I know are missing a portion of a digit? Absolutely Feckin Awesome!
Mine was a table saw. I published a video last week explaining it...
I've got a single phase electric motor that is part of a standard single stage vacuum pump that will not spin. It has been running flawlessly for about a year on my Harvestright freeze dryer. The shaft spins freely by hand (after taking off the cover to the fan).It doesn't make any noise, or very little noise. It has two capacitors and I tested them with the multimeter and they are within spec and have greater than 1 meg of resistance after 5 to 10 seconds on the ohmmeter. When I plug it in and turn on the switch, sometimes it will spin a tiny bit, maybe 5 degrees or less and no hum. Otherwise it does not spin (or hum) at all. Both capacitors have about 120Vac across them when turned on. So I am kind of stumped. ANy ideas??
I also tried to spin it manually while energized and it did not help at all. It was like it was turned off.
Sounds like it's not getting power. The only thing I can think of is a centrifugal switch. Google that and see if your motor has one. It might not be working properly. Good luck!
I purchased a new 1.5 hp 110 volt replacement motor for a table saw from somebody on Craigslist. It would not run full speed, I checked the capacitors and the run capacitor was bad. I bought an exact replacement one off of eBay and put in it. I ran it without a load for about 2 minutes then it blew the run capacitor again. What are my options? Can I put a bigger one in? How would I check to see what is wrong with it? Thank you!
If it has a start capacitor it will have a clutch that engages to start the motor and then disengages when the motor spins up. You should hear a definite click when it gets spinning. I would check to see if the clutch is stuck. Hopefully that will help, other than that I don't know.
This is new to me. A new capacitor installs with or without a charge?
You need to make sure the capacitor is discharged. Watch a video on it.
Touching a charged one is like touching the mains
The capacitor will charge after you put it in. They don't charge like a battery, it's instant.
What is the reason capacitor keep damaged?
I just put 9 brand new capacitors on my 30 HP baldor motor and it still won't start.
Is it possible that the new ones are bogus [as in not the rating they claim]?
Sir,, how can u set the multimeter to check the micro farrad
Unfortunately a normal multimeter cannot test a capacitor. You need one like this: amzn.to/34UuLkV
What if it trips the breaker almost instantly? The belt only moves a couple inches.
Sounds like a short someplace.
Notice that the video image faded when you started the motor without the capacitor connected. I can guess the cause, but does anyone know the definitive answer?
i have a new motor but the capacitor is missing how do i find the right one Hope you can help Thanks
I would search for the motor online and see if that would lead me to the capacitor. Other than that I don't know.
My motor always needs to be Kickstart on the fan with a screw driver. I cleaned it but it always needs to be jump started. Could it be the capicitor
Very well could be
Hey I've replaced 3 capacitors on a electric log splitter, 1 popped, 1 started smoking,the last one the company just swapped out a new one saying they might of given me a bad one. Free of charge. I put the new one on and fired up the splitter it ran great through about 3 cycles then it exploded. The whole system runs just fine but I can't figure out why I'm blowing capacitors. Or where to look to fix it. Can you help giving me a direction to go on fixing this? Please and thank you.
You're missing some sound for about 20 secs at the beginning, 17 seconds in. 👍
Thanks for letting me know. I just removed that part to fix it, I hadn't said anything worth hearing... I had an issue with my editing software, actually a user error. Thanks again for letting me know.
Isn't a starter capacitor polarized?
I have the same vacuum and that's a Jet 2 hp motor. It had a Seika 400mfd 125 volt capicitor. Mine just blew and now it makes two...... I just took the motor apart and think it might be a "starter relay".
Thanks for identifying the motor.
Thanks for the info. Very helpful.
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?
mpp cap 350v 12uf size replace it with a 12uf 450v
Will that be ok
That should work. A higher voltage is fine.
@@SoatMon thank you very much it's basically the same motor as yours but it runs a big sander
Does it make a difference which terminal the wires are connected to? My motor has two identical black wires from the motor...….
Nope - either wire works
Sir im from Philippines. My problem is i already change the capacitor the run and start capacitor but still humming
Check the wiring to make sure it is correct, check to make sure you have the correct capacitors, make sure the axle will spin. If all of that is correct the windings may have gotten too hot and ruined.
May be best to short out the Capacitor prior to testing on the meter and as taking on this helpful teaching role it may be better to teach the correct wording rather than MFD or UF 'microfarads' being better and actually completely correct
that missing finger!!
Yeah, I can't find it anywhere.
Soat Mon
That was a great answer!!
Watch your fingers
Safety Nazi alert! Regarding shorting the leads with a screw driver, could a resister be used to drain the capacitance? It is my unexperienced knowledge that large capacitors can cause some dangerous discharges and actually arc and melt screwdriver tips. Please comment and let me know if this comment is out of line. (No disrespect intended)
No problem. You are correct, I definitely am not the one to follow for safety concerns. That is the way I have always done it and for capacitors this size and smaller I have never had an issue however on bigger ones you could certainly damage a screwdriver. I think for a resister you would have to figure the correct resister and get a large one because you could easily blow a resister, not sure but I agree there would be smarter ways to do it. No offense taken.
Easy, as a mechanic I will answer, You just use one of your shitty screw drivers for jobs like this,
I have mac screwdrivers that are 30 years old from my grandfather But those are the one I treat well.
Sir great explanation but what happened to your finger?
Tablesaw
Shorting a capacitor with a screw driver gives it a huge internal shock Not recommended. Use a resistor or even a light bulb to drain the voltage.
😂
uF and mF are NOT the same! It is a 1000x different. uF = Micro Farad, mF = mili Farad 1/1,000,000 and 1/1,000 respectively.
Correct
The little u is actually the small m in Greek μ