Repair of the start switch on the centrifugal motor.
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- Опубліковано 15 сер 2017
- This one shows how to repair the start switch on the centrifugal start motor. This video is part of the heating and cooling series of training videos made to accompany my websites: www.graycoolingman.com and www.grayfurnaceman.com to pass on what I have learned in many years of service and repair. If you have suggestions or comments they are welcome.
If you are a homeowner looking to repair your own appliance, understand that the voltages can be lethal, the fuels are highly flammable and high pressures are used. Know your limits. - Навчання та стиль
Thank you very much. When I watched your video, I solved my problem differently
Very helpful video on how to fix the centrifugal switch on split phase motors. I was able to repair a similar motor after watching this video. Thanks!
This video helped me out a lot today and I just wanted to say thanks!
I picked up a used 1 1/2 HP motor from Craigslist, and it worked fine for a few days, then suddenly it stopped and just hummed until the breaker would pop. I dug in and found the capacitor tested fine, so I was thinking I just got sold a crappy motor with probably bad windings or something. I cleaned up the contacts on the centrifugal switch and she sprung right back to life. Thanks!!
wanna thank you for all your time and your willingness to share your knowledge i am a us marine veteran and 7 years sober your videos are very helpful i do currently work in the feild
Thanks for the support. Glad you are in the field. Thanks for your service. By the way, marines are crazy, glad I was in the Army.
GFM
Thanks boss, now I finally understand. This was so helpful to me. Much appreciation.
Thank you,I have one of those motors,that I want to use for a project,your video was very helpful.
That was a ease fix. You saved couple dollars there. Good job.
Thanks brother, I have this kind of trouble with my 5hp ingersoll rand compressor motor, I will try that at home
Gary......keep doing videos.......your are a wealth of information and very much appreciated!
Thanks for the support.
GFM
saved another one from the scrap pile, nice work gfm!!
Brilliant! easy to understand and ofc you will get 20 years out of this! i just did something similar to my hayward pump when the motor wouldnt start and it works now. cheers and liked and subbed ofc!!
still learning sth almost every day at 45 yrs old.
Awesome job, thank you
VERY VERY VERY Helpful.. Thanks a bunch!
Great video, I found a bunch of wasp nests inside one motor on an air compressor.
this is a great video on failed start switch/circuit, first one I repaired was early to mid 90's, the springs broke on the centrifugal weights on a deep well jet pump, the tank bladder was bad and it was short cycling like mad :)
the contact setup rather cheap looking to start with and of chinesium motors are fairly cheap now.
it's still a good skill to be able to repair things on short notice, you just never know :)
I have had the spring problem also. It was an easy fix.
Thanks for the informative vid.
thanku sir I faced same problem now u solved it
Great explanation, thanks for sharing..
Welcome
GFM
Well done! Thank you for sharing this - I think I’ve got the same problem on my compressor motor. It operates in a very dirty environment.
You sound just like Hank from King of the Hill! I didn't know you worked on electric motors too!
Yep same problem with my compressor motor, a general electric, and sure enough that was the problem, thanks buddy.
Welcome
GFM
Very well done thank you sir fix my air compressor
Open relays can have lots of things in them. I heard of a roach caught between the contacts when it closed.
The switch is probably making contact but it sounded awfully scratchy like the centrifugal governor wasn't retracting away from the switch like it should. I also noticed there was no "click" from it when it started and wound down again.
thanks, you just saved me $200.00
Thanks for the video. But my problem is the plate that makes and breaks the contracts that is mounted on the rotor behind the contacts. (It has springs) I can't find a replacement! Have a pic but can't send
I have a 1978 Craftsman 11 amp radial arm saw with a direct drive motor, and it's a beautiful motor in mint condition with a capacitor start. The problem is, it is super squeaky. From what I can tell the centrifugal contacts in my motor are sticking and not opening, because the motor runs great but continues to squeak and when it winds down you can't hear the "click" as the contacts close again. I think people rush to replace motor bearings, when it's actually the centrifugal switch causing noise or squeaky. I am not exactly sure yet how to fix it. I'm hesitant to put lubrication on anything, but I might try spraying the spring and non-electrical moving parts with silicone spray.
In my opinion, it's a shame that so many otherwise good parts are scrapped because of minor problems like a little dirt in the contacts. Great video though!
Nice video. I would have shot some contact cleaner in there before using abrasives. But nonetheless good video to prove not everything you condem is garbage.
Thanks for the video again.
Funny, I tore a motor open today that won't start unless it has some help spinning up, but it's showing the exact opposite behavior. Measuring across the start switch gives me a reading regardless of whether the contact is closed or not. Could this be from a shorted winding somewhere? I'm stumped, going to probably have to order a new motor for the tool.
Thanks for this video! I have a motor that sat for a few years that starts up fine but then never switches to run mode and thus pops the breaker. I am going to dig in tonight and see if the start switch is stuck or gunked up.
it sounds like its grinding during the last part of the video. its going bad?
Just the info I’m looking for to explain the magic smoke coming out of my 5 hp split phase motor I might be able to fix it now thank you
Magic smoke in these motors is very limited once it comes out it's next to impossible to replace .
if you sand the plating away, do the contacts have more of a chance of arc-welding themselves closed, permanently? does the plating protect the contacts from being eroded away by repeated opening and closing of the start switch?
Yes they can weld together. The plating is, I believe, a silver alloy that resists corrosion during the high temperature arc of the contacts opening.
GFM
This is a very good video!.. Thank you for sharing your knowledge.I wonder what is the little brown box with three wires on the back plate of that motor. I thought that was the switch, and tried to pull it out, and...(!!!) did damage it, can one get a replacement?..It says on it MEJ38AX...
Its a high temp limit. Very hard to get this type of part for a motor.
GFM
Can you tell me if the terminals when disconnected should be showing short or open?.. or any other combination?...
It is a normally closed switch.
GFM
Yes, indeed. I found another one and found that out.
Sir you sound like hank hill with all due respect
☝️ this made me laugh 😂
on some gas pack roof top units, how the induced draft motor centrifugal switch works? woukd you help to explain please?
I have a video on these: ua-cam.com/video/ZOjWdQ5RndA/v-deo.html This one does not include the Carrier RTU that uses a small generator on the end of the inducer shaft that interfaces electronically with the control board of the RTU.
GFM
Thanks for the video.
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?
You probably have a failure in the electronics. Look for burned components mounted on heat sinks.
GFM
Can't you replace the contacts, like we used to in cars
Thanks, good video
James
The parts aren't available. Also, these parts usually fail at the end of the life of the motor. Replacement results in a repair that may not last long.
GFM
Thanks. Any ideas on a similar motor that hums and spins very slowly? When I put light hand resistance on the shaft, it either bogs down entirely or wants to change direction.
You can try a new cap, but the windings are probably shorted.
GFM
@@grayfurnaceman Thanks. Cap tested fine. And found that the centrifugal switch is busted, too. Easy come easy go for this salvage project.
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
If the switch does not open at 75% of motor speed, either the switch is bad or the load it too high. Try it with no load.
GFM
How about the Hall Effect switch for a Carrier rooftop?
I have never been able to do anything to get one of those to work when they fail.
GFM
If the contacts are plated, is the coated base a conductive metal or a non conductive substrate, if it is a conductive metal then an fine abrasive is no issue, a non conductive substrate then will render it unusable?.
The plating is there for a good reason. It conducts well even during arcs. The substrate is metal but does not work well with arcs. No abrasive.
GFM
bring it to my shop
Can You Help me? I Have a Dayton 5K968g 220v 5 hp Motor For my Shops air Compressor. The Points are missing a connector. do You Know where I can find a switch? There's No Part # on the Switch
Unfortunately, there are generally no parts available for smaller motors. You can try a motor rebuild shop.
GFM
Great video! I noticed something interesting though. At 5:15 when you started the motor the first time, it looks like it spun one direction. But when you started it at 5:45, it looks like it was spinning backwards. Why is that, or is it just an optical illusion? Thanks
I did not notice that at the time, but you are not the first to say that. I don't think I still have that motor but I will look.
GFM
@@grayfurnaceman Oh okay I thought I was losing my mind for a second LOL. Could there be a defect in an AC motor that causes it to intermittently spin backwards?
I have seen it happen.
GFM
@@grayfurnaceman That is very interesting!
I’m going to see if this works for my green house
A little help please. My pond pump motor does the same thing. when I give it help it starts and runs. I opened it up and it is very similar to your motor. In the center around the shaft is a disk than has two positions it pops in and it pops out. When the motor is off it is popped out the disc pushes against the centrifugal switch causing the contacts to touch. I did every you did put the motor back together and it started right up, but only once. When I opened it back up I noticed the center disc was in the in position. Popped it out tried again same thing. I tried stretching the spring arms a little and lubing every thing up. Still only starts once center disc remains in. Any suggestions as to an adjustment. Thanks
Also the centrifugal switch doesn't seem to have any regular coil type springs just some sort of spring steel devices?
The problem is probably not permanently repairable. You will end up replacing the motor.
GFM
Is there any thing I can try. I did stretch out the steel spring system and it helped a little it started 3 times by itself. I"m afraid if I stretch them too much the centrifugal function will not work and it will burn up the start windings. I want to post a pic how?
You could try cleaning the contacts.
GFM
What are you using to power that motor?
Its 120 volts AC.
GFM
Sir your video is too much good.but sir I have a question this motor is one run winding and one start winding normally after power on run and start winding both are energised and after 70%speed start winding disconnected and motor run by run winding.no capacitor use here is it's working principle. Please give feedback.
The start winding, when energized will give the rotor a boost because it is out of phase with the run winding. If more starting torque is needed, a capacitor is added to increase the out of phase condition. Hope this helps.
GFM
@@grayfurnaceman thank you sir for your reply.
Finally! someone says something besides, "Change the capacitor." But there ain't none!
But uh... mine still hums. Can a guy buy a new start switch?
Unfortunately no. But you could try hitting the motor lightly with a hammer. It may break the switch loose, but it will fail again.
GFM
Yes you can. If you know the model number you can change the switch. Check Amazon they have a bunch of them.
@@stocktondad Interesting. I will check it out.
GFM
Al White Bought a switch today and changing mine on a B&G motor as I speak. Had on hand at our local distributor. Saved tons of $$$😀.
EXCELLENT VIDEO grayfurnanceman!!!
So why did the motor run clockwise the first time you started it, but ran counter-clockwise the second time you started it?
In the end, I was not able to use that motor as the run winding had a short inside, but it made a good demonstration of how to replace the start switch.
GFM
Sounds like it would make a good demonstration of how to use a megohmmeter too. (wink, wink, nudge, nudge.) ;-)
Question: Which swear words, work the best? The ones I am using, are not helping.
My father always used "God %#$&* the thing".
GFM
if you fold the sand paper in half, you sand both sides at once...
I may be seeing things. But the motor on its last two starts up rotated CW and then second start CCW. ????? Something not right.
Yup, you see'd it right, something amiss there Ed. .
bearings should be replaced as well,hands down
This video is not really advocating replacement of start switches or for that matter, bearings. Most of these motors are not worth the hassle to replace these parts. Replace the motor.
GFM
lo how can i call u ? ill pay u for data
will i get 20 years out of it lol
dust caked and killed mine
Very common
GFM
@@grayfurnaceman and i just fried the capacitor after replacing the centrifugal switch. smoked it. went too deep to the plate, i guess . off to orvac tomorrow
Shame you can't fix women this easy.
testify brother!
No comment.
GFM
Michael Mace wow
you probably need more swear words... lol
Michael Mace very manly joke
Do not hit the axle and the motor bearings, you will pay the consequences, after hitting the axle the bearings, if you change them, will get stuck in the axle.