Fan got stuck while I was asleep.

Discussion in 'General Electronics Chat' started by Sightscout, Jun 4, 2016.

  1. Sightscout

    Thread Starter New Member

    Jun 4, 2016
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    Hi guys so I have a fan running at 120V 0.5A 60Hz and the other day I tried adding a filter to it. Well at night the filter became entangled in my fan and now it won't start. This happened before but I was able to turn off the fan and untangle it. I guess I just didn't install the filter correctly. So I inspected my fan(Unplugged of course) and the threads are not burnt out, it still spins freely on its bearings and the wires seem to be unburnt as well as connected properly. (There doesn't seem to be a temperature cutoff circuit anywhere on the coils. I guess it was made not to run at a speed that it could overheat at.) So I am assuming it is the capacitor because the regulator still sends power through (I only checked once so I need to double check). Do you guys know if the fan being stuck like this could've caused the starter capacitor to short out? It is a 250v 3uF 50/60Hz capacitor.
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    Model? Link?
     
  3. #12

    Expert

    Nov 30, 2010
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    6,814
    Let's see, "I jammed the fan motor and let it stall for half the night. Can you guess which part failed?"
    Yes. The motor overheated and the windings are bad.

    "Please tell me the $3 capacitor failed."
    Sorry. Can't guess which part from here. Just try replacing the capacitor like anybody here would. If that doesn't fix it, the motor is bad.

    Is it worth trying a new capacitor? Your choice.
     
  4. Sightscout

    Thread Starter New Member

    Jun 4, 2016
    2
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    yeah Vornado 630

    www.vornado.com/circulators/630-Mid-Size-Circulator
     
  5. dl324

    Distinguished Member

    Mar 30, 2015
    3,248
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    Welcome to AAC!

    I'm with #12; motor died.
     
  6. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
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    That fan has a shaded pole motor. The capacitor isn't for starting; it's for speed (phase) control. There's a possibility that a thermal cutoff opened instead of the coil insulation failing. Any such thermal cutoff would be wrapped in contact with the coil windings, sometimes buried in the windings so repair may be infeasible.
     
    nsaspook likes this.
  7. ISB123

    Well-Known Member

    May 21, 2014
    1,239
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    Most likely windings failed but still for a fan that costs 80$ I would expect some sort of protection.
     
  8. Tonyr1084

    Active Member

    Sep 24, 2015
    535
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    Just about all fans have fusible links in them. They are Fuses AND they are Links that can melt with temperature. Their function is to prevent a fire AND to blow in case too much current is drawn.

    I have a fan downstairs that I'm keeping for the magnet wire. It too has a blown fusible link. Spins freely and all. Radio shack sells them for less than $2.00. Since I only have the motor, not the fan blades - the motor is just being kept for parts for later on.

    Mother-in-law had a washer go bad. "Mode Shift Coil Failure". When I checked the coil - it read Open. GE wanted $135 for a complete new mechanism. I just wanted a new coil - which they refused to sell. So I opened the coil and found the fusible link. Tested it - it was open. The rest of the coil was pristine. After calculating the running current and estimating the temperature I concluded that the fusible link they installed was rated for 102% of normal operation. I upgraded to a fusible link rated for 120% normal operation and put it all back together. Machine has been running fine ever since. All for less than $2.00 (not to mention tax). Big difference between $2.00 and $135.00 PLUS paying someone to install the mechanism. (I wasn't going to do it)

    If your motor won't run then check the common to any and all other coils. If they show open then - fusible link has blown. Like regular fuses, once they blow they're done. Just be sure to replace it with the proper rated link, otherwise you run the risk of it getting stuck again, possibly starting a fire next time.

    Capacitor? Eh ~ I'm skeptical about that. But since I can't test it for myself I can't say for sure.

    Quick note on my choice for 120% normal operation: High end equipment is generally engineered to operate at 133% of normal operating conditions and medical, cars and aircraft are all engineered to 150% normal operation conditions. I worked for a steel fabrication shop that built water tanks (and other). If a tank was to operate at 120 PSI normal conditions it was tested to 180 PSI. If it passed the higher test it was certified. If not - it was sold for scrap. We never scrapped any tanks. That's good engineering practice.
     
  9. #12

    Expert

    Nov 30, 2010
    16,305
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    The only 20 inch box fan I bought has the fuse hidden in the power plug!
    Of course, I immediately wrote on the fan, "Fuse hidden in plug".
    That's the first 20 inch box fan I ever bought because I have survived by picking up discarded fans at the side of the road and replacing the fuse in the motor for the last 40 years.
    I have also saved 24 volt control transformers by cutting into the paper and replacing the fuse. I have one that has been working properly for 35 years since I replaced the fuse. Just another scam to sell you an expensive part instead of a $2 fuse. Much like using a microprocessor instead of a 555 timer and an op-amp.:mad:
     
  10. merts

    New Member

    Apr 1, 2016
    8
    0
    I agree.It could also be a fusible semiconductor hidden in the windings.
    Check your coils for continuity.
     
  11. wayneh

    Expert

    Sep 9, 2010
    12,137
    3,054
    Given the time of day of your post, we'll let it slide. If it was 8AM, I'd say we were off to a grumpy day. o_O
     
  12. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    All of that has been covered. It's good form to read the entirety of the thread before replying to avoid duplication and a needless increase in thread length. If you find what you had intended to say already posted, you can indicate agreement or appreciation of the post by clicking the "Like" button at the bottom of said post.
     
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  13. #12

    Expert

    Nov 30, 2010
    16,305
    6,814
    I will still hate microprocesors pretending to replace two chip analog circuits tomorrow.:mad:
    If I can find a place that will replace any defective MPU and its programming for the price of the MPU, I promise to get over my vendetta against using over-complication to obstruct repairs and achieve higher cash flow.
     
  14. wayneh

    Expert

    Sep 9, 2010
    12,137
    3,054
    My microwave just went tits up. The PCB appears to be dead, and stupidly costs as much as a new microwave. :mad::mad:

    So now the shell, turntable, magnetron, transformers, switches, temperature fuses, fan and more, are all worth precisely zero. Less my cost to take it to a recycler.

    I get it that you need a micro to throw up the nice digital display and all that, and to know how to cook popcorn or potatoes. But a PCB that costs more than the whole microwave? WTF? The greenies are worried about how many squares of toilet paper I use to wipe my...exit area. How about some attention to guaranteed obsolescence?
     
  15. panic mode

    Senior Member

    Oct 10, 2011
    1,320
    304
    "Hi guys so I have a fan running at 120V 0.5A 60Hz and the other day I tried adding a filter to it. Well at night the filter became entangled in my fan and now it won't start."

    if this happened to someone in Korea, they would be relieved... ("dodged bullet" ;))

    https://en.wikipedia.org/wiki/Fan_death
     
  16. MrAl

    Well-Known Member

    Jun 17, 2014
    2,438
    492
    Hello there,

    In the past i had repaired several fans where the thermal fuse opened sometimes for no reason at all, and of course that opens the circuit so the fan does not get power anymore. This was the main problem with several fans. The thermal fuse is often hidden somewhere that might not be seen until the fan is disassembled. Once you get the coil section visible you should see something by following the wiring. The wiring will have to lead to the thermal fuse because it is soldered to the wire in series.

    The second problem that comes up is the armature jams due to the lubricant drying up, and that could cause the thermal fuse to go too. This requires taking the armature out and cleaning all the bearings, then oiling again. The best oil i have found to use is the synthetic motor oil as that lasts the longest before it needs oiling again.

    You can check the plug to the fan with an ohmmeter. If the coil is open you wont see any resistance when the switch is turned on. Also, if you turn the fan on with it plugged in and you hear a slight 'groan' then the armature is jammed. If you do not hear any groan then the coil is open, either because of bad wire or because of that thermal fuse.

    Good luck with it.
     
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