Introduction: FAN Repair

I had accumulated three floor standing fans which had stopped rotating. Had cleaned and oiled its shaft bearings and even changed the squarish capacitor but still not turning. Was about to throw them away when I thought "... what's the harm in dissecting them, I could learn something from it...!!"

I had asked a few servicemen and all I got was a short "...there's an internal thermal fuse...". I trawled the web for months but just could not find any info on where the fuse was and how to replace it. Finally I decided to sacrifice one of the fans and dissected all the wires going into the windings. 

From this came the schematics of the fan, but only up to the motor windings.

This instructable comes in 2 parts: (I)Troubleshooting and (II)Fuse replacement.

Step 1: Materials Required

Cross head screw driver
Flat tip screw driver
Scissors or Pen knife
Soldering Iron and some Solder
Some string about 0.5mm in diameter 
Spare wire, about 60cm long
Capacitor 1.4uF 450VAC (if required)
Thermal Fuse 130degree C, 1A, 250Vac
  (note: I could only find a 2A 130deg replacement @$1.50SGD a piece from the local electronic component shops. Sorry I don't have equivalent part number from Mouser, RS n Digikey)

 

Step 2: Troubleshooting

WARNING:
If you are NOT trained in electrical repair, please STOP here.
It would be wise to spend the money for a replacement fan and give the faulty one to someone who knows. We are dealing with 250VAC, so be extra careful. You proceed at your own risks.

The Schematics :
At this juncture, I assume you know and have verified that the timer and speed selector are working fine (i.e. voltages are present at output of the speed selector (grey, orange and red wires)), see schematics and picture.

The colors of the wiring used in my fan may be different from yours, so make a note.
 
Troubleshooting the Thermal Fuse :
1. Disconnect power to the fan.

2. Open up the control unit cover.

3. Take your time to trace the wiring and note down its color and location. It should be similar to the schematics above.

4. Using the spare wire, connect from point “A” to “B” to shunt the fuse. For my case, “A” was the blue “neutral” wire on the terminal block and “B”, the grey wire on the big squarish capacitor.

Once done, make sure your fan (without the blades of course) is resting properly and securely as we are going to power it up.

5. Connect and power up the fan motor. If the fuse is faulty, the motor will rotate, mine did. If it did not, it might also be that point “C” was used instead of “B”, since you could not know which terminal it was. No worry.

6. Disconnect power. Move point “C” to “B” and power up the fan again. If it still would not rotate, it’s likely the capacitor. 

7. Disconnect power and remove the spare wire.

Replacing the Capacitor:
1. Disconnect power.

2. De-solder (or cut) the wires at capacitor terminals and connect them to a new capacitor (same type).

3. Power up the fan. If the motor still refuses to rotate then I believe the problem is with the motor windings and it's time to say bye-bye to the fan.




Step 3: Thermal Fuse Replacement

Once the thermal fuse has been determined to be the cause, here we go...

Removing the Thermal Fuse:

Disconnect power to the fan before proceeding.

1. To make fuse replacement easier, we need to free the motor from the control unit keeping its wiring harness as long as possible. The harness has 5 wires going into the motor housing. By tracing this harness, starting from the motor housing, I found the Ground (green/yellow) and Neutral (blue) wires ending at a terminal block and another three (grey, orange, red) ending at the speed selector.

2. Remove the Ground and Neutral wire (no cutting required) from the terminal block. De-solder  the grey, orange and red wires at the speed selector, note their location first. (You may have noticed that I cut the whole harness about 10cm from the motor…big mistake...but that was way before I decided to do this!!)

3. Using a flat tip screw driver as a lever, pry the motor housing mount rod away from the control unit.

4. Remove the oscillating unit and detach the capacitor.

5. Remove the metal housing screws. Carefully remove the rotor and the windings slowly by giving it enough slack from the harness.
 
6. The windings are tied by strings and coated with some kind of lacquer. We need to cut some of them (see the “X” points in the picture) using pen-knife or sharp tip scissors. Look for a bulge (where the fuse is) and notice where it ends.

7. Carefully slice open the black sheath cover to expose the brown woven sheaths, also tied with strings.

8. Trace the blue Neutral wire from the harness towards the windings. You will notice it ended inside the biggest sheath which is on top. This is our target. Cut the strings tying this sheath.

9. This big sheath, which is flattened, holds the fuse and another sheathed wire. Use fingers to lift it and press on its sides to form back its tubular shape. 

10. With wriggle, press and pull action, slowly remove this sheath and the thermal fuse will be exposed. Put the removed sheath aside to be reused later.

11. Notice that one of the fuse’s leads is also sheathed to prevent electrical contact. Slice the SIDE of this sheath lengthwise about 10mm. Expose the lead through this cut.

12. With both leads exposed, cut them off as close to the fuse as possible. This will give us enough room to solder the new fuse.

13. Trim the leads of the new fuse to about 10mm and tin them with solder.

14. Solder the new fuse, polarity is not important but you may follow the old fuse direction.

15. Move the cut sleeve to cover back the lead exposed in step #11above.

16. Cover the fuse and its accompanying wire with the big sheath removed in step #10 above.

17. String the new fuse assembly to the windings as neat as you can. Fold back the black cover and string again. Ensure no string or black cover sheath is protruding into the rotor area.

18. Carefully place back the windings and rotor into the motor housing.

19. Secure the housing and mount back the oscillator and the capacitor.

20. Insert the motor housing mount rod to the control unit, a little pressure is needed here.

21. Dress back the wiring harness and reconnect the Ground and Neutral wires to the terminal block. (For me, I had to solder back all the wires and insulate them with heat shrinking tubes. I also had to de-activate the oscillator to prevent them from rubbing against each other)

23. Re-solder the grey, orange and red wires back to the speed selector.

24. Power on the fan to test. Cover back the control unit and you are done.





 

Step 4: Finally...

I did not use lacquer to protect the windings and its been operating for nearly 2 months now at around 6 hours a day.

To prevent overheating, I modified the timer to disable the permanent "ON" selection. By using the timing mechanism there will be resting time in between, when no one is in the room or no intention to use the fan for a while.


Comments

author
CindylynnJ (author)2017-08-22

I have an Orient stand fan with 4 blades. Was working great. My husband accidentally pulled some of the wires out. Now I need to know where they go, so I can put them back. Its got blue, black, white, red. The white and black wires is what I need to know.

author
TsujanP (author)2017-06-16

Can i use 2.2 uf capacitor for 1.5 uf ???

author
mhd sahal (author)2017-01-26

Can you help me??

how the table fan oscilate

author
rivera2016 (author)2016-08-21

Hi, i need help i have a problem fixing my fan, i cleaned & oil it, but my fan doesn't work still vibrating, i tried trouble shoot it looks fine all in tack (i think). i check the capacitor still working. what seems the problem of my fan?

1) I have a question how can you know if the therma fuses is not working. (if still vibrating does it means that the therma fuse still ok?)

2) Is your fun same problem mine. (only vibrates)

author
IoannisD1 (author)2016-08-01

Hello

A simple question. On the schematic diagram shown on page 2 "Troubleshooting" point B of the capacitor is linked to neutral (blue wire) via the thermal fuse

BUT where does the C connection of the capacitor (white wire on the diagram) is linked to?

Thanks

author
Mukiez007 (author)2016-07-20

I followed all the steps and was able to fix my fan though it's a little complicated but was very adventurous and this is actually my first time....and I kind of did something though not healthy but it worked as related to my "terminal fuse" I was able to get a new capacitor but couldn't get the terminal fuse so I short-circuit the fuse don't know if that's the right word "short-circuit" but it has a good ring to it. anyway this is what I did, I rowed the fuse with a very slim wire and solder but end and boom I have me a working terminal fuse....and I CAREFULLY followed the rest steps. I don't know how long it will live but it's working awesomely well. ONLY TRY THIS IF YOU CAN'T GET A NEW TERMINAL FUSE.

author
ChrisH510 (author)Mukiez0072016-07-28

What type of fan did you work on?

author
MaggieM57 (author)2016-06-01

where does one purchase a capacitor for stand up fans.

author
IhemeduF (author)2016-05-22

how do i disconnect the timer and still have my fan working

author
melvjoe92 (author)2015-07-05

I have a panasonic table fan.i want to change the bearing of the motor but when i remove the motor i didnt realize there is a connector attached at the coil winding.the connector pulled off from the coil winding.Is there any way to solder them back or dispose the fan?

author
Raghu.YR (author)2015-04-07

I have problem, i had a bajaj table fan., fan wings are made of fibre those were broken last time because it fell down from a table, afer that i cuecked with the electrician he told also want to change the capacitor since it's not pushing to rotate, but my issue is wings are breaking all of a sudden during rotation., wat is the reason for this...?

author
nani.monku.aru (author)2015-01-26

I have a weird problem with my fan. Its panasonic's . There are no problems with the 3A fuse, the capacitor nor the grease. So i thought that maybe the circuit is out so I decided to run this stupid test. I turned the fan on, and touched the fan directly( to check whether there is any flow of current) since i dont have a test pen thaha. So i got shocked by the current! The current is present! SO WHATS THE PROBLEM HERE??? PLEASE HELP!

author
Klownfish (author)2014-01-05

Any idea on standing fans, that is able to spin briefly for approximately 2 secs and just stops. I have accumulated 3 fans of different makes and brand. They have the same trouble too! Tried replacing the capacitor which doesn't see any improvement. Also tried to short the thermal fuse contact that don't help.

author
Mihsin (author)Klownfish2014-10-27

The grease applied to the spindle gets hard by heat and time. Soften it by spraying anti rust oil, scape it, and replace it with soft heat resisting grease.

Good luck

author

see if the gear of the fan is not align

author
AngelaC1 (author)2014-09-10

i have a problem with the speed of my fan, how can i increase its speed...?

tri-staterepairs

author

repalce its capacitor

author
eddievamansec (author)2013-10-04

This instructables program help me so much. I don't have to go every now and then to repair shop.

author
edywnr74 (author)2012-12-25

i like

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