electric fan repair

8/11/2019 Electric Fan Repair

1/12

I had accumulated three floor standing fans which had stopped rotating.Had cleaned and oiled its shaft bearings and even changed the squarishcapacitor but still not turning. Was about to throw them away when Ithought "... 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 aninternal thermal fuse...". I trawled the web for months but just could not findany info on where the fuse was and how to replace it. Finally I decided tosacrifice one of the fans and dissected all the wires going into thewindings.

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

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

Step 1: Materials Required
http://cdn.instructables.com/F4I/QTK9/GIRSYGM9/F4IQTK9GIRSYGM9.LARGE.jpghttp://cdn.instructables.com/FZX/0OEY/GJ7MLWVC/FZX0OEYGJ7MLWVC.LARGE.jpghttp://cdn.instructables.com/F4I/QTK9/GIRSYGM9/F4IQTK9GIRSYGM9.LARGE.jpghttp://cdn.instructables.com/F4I/QTK9/GIRSYGM9/F4IQTK9GIRSYGM9.LARGE.jpg


2/12

Cross head screw driverFlat tip screw driver

Scissors or Pen knifeSoldering Iron and some SolderSome string about 0.5mm in diameterSpare wire, about 60cm longCapacitor 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 equivalentpart number from Mouser, RS n Digikey)

Step 2: Troubleshooting
http://cdn.instructables.com/FZX/0OEY/GJ7MLWVC/FZX0OEYGJ7MLWVC.LARGE.jpghttp://cdn.instructables.com/FZX/0OEY/GJ7MLWVC/FZX0OEYGJ7MLWVC.LARGE.jpghttp://cdn.instructables.com/FZQ/UQ72/GINP163W/FZQUQ72GINP163W.LARGE.jpghttp://cdn.instructables.com/FZX/0OEY/GJ7MLWVC/FZX0OEYGJ7MLWVC.LARGE.jpg


3/12
http://cdn.instructables.com/FZQ/UQ72/GINP163W/FZQUQ72GINP163W.LARGE.jpghttp://cdn.instructables.com/F3E/F6AY/GINORUV0/F3EF6AYGINORUV0.LARGE.jpghttp://cdn.instructables.com/FZQ/UQ72/GINP163W/FZQUQ72GINP163W.LARGE.jpghttp://cdn.instructables.com/F3E/F6AY/GINORUV0/F3EF6AYGINORUV0.LARGE.jpghttp://cdn.instructables.com/FZQ/UQ72/GINP163W/FZQUQ72GINP163W.LARGE.jpghttp://cdn.instructables.com/FO5/ICB9/GINP5CND/FO5ICB9GINP5CND.LARGE.jpghttp://cdn.instructables.com/F3E/F6AY/GINORUV0/F3EF6AYGINORUV0.LARGE.jpghttp://cdn.instructables.com/F3E/F6AY/GINORUV0/F3EF6AYGINORUV0.LARGE.jpghttp://cdn.instructables.com/FZQ/UQ72/GINP163W/FZQUQ72GINP163W.LARGE.jpg


4/12
http://cdn.instructables.com/FJE/06FR/GJ7MLWZK/FJE06FRGJ7MLWZK.LARGE.jpghttp://cdn.instructables.com/FO5/ICB9/GINP5CND/FO5ICB9GINP5CND.LARGE.jpghttp://cdn.instructables.com/FJE/06FR/GJ7MLWZK/FJE06FRGJ7MLWZK.LARGE.jpghttp://cdn.instructables.com/FO5/ICB9/GINP5CND/FO5ICB9GINP5CND.LARGE.jpg


5/12

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 thefaulty one to someone who knows. We are dealing with 250VAC, so beextra careful. You proceed at your own risks.

The Schematics:At this juncture, I assume you know and have verified that the timer andspeed 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, somake 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.
http://cdn.instructables.com/FJE/06FR/GJ7MLWZK/FJE06FRGJ7MLWZK.LARGE.jpghttp://cdn.instructables.com/FJE/06FR/GJ7MLWZK/FJE06FRGJ7MLWZK.LARGE.jpghttp://cdn.instructables.com/FJE/06FR/GJ7MLWZK/FJE06FRGJ7MLWZK.LARGE.jpg


6/12

Once done, make sure your fan (without the blades of course) is restingproperly 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 usedinstead 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, its 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 anew capacitor (same type).

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

Step 3: Thermal Fuse Replacement
http://cdn.instructables.com/FIS/OEP5/GJ7MLXLB/FISOEP5GJ7MLXLB.LARGE.jpg


7/12
http://cdn.instructables.com/FIS/OEP5/GJ7MLXLB/FISOEP5GJ7MLXLB.LARGE.jpghttp://cdn.instructables.com/FIS/OEP5/GJ7MLXLB/FISOEP5GJ7MLXLB.LARGE.jpghttp://cdn.instructables.com/F59/VQGE/GJ7MLXNJ/F59VQGEGJ7MLXNJ.LARGE.jpghttp://cdn.instructables.com/FIS/OEP5/GJ7MLXLB/FISOEP5GJ7MLXLB.LARGE.jpg


8/12
http://cdn.instructables.com/F59/VQGE/GJ7MLXNJ/F59VQGEGJ7MLXNJ.LARGE.jpghttp://cdn.instructables.com/FM6/E3SU/GJ7MLXHA/FM6E3SUGJ7MLXHA.LARGE.jpghttp://cdn.instructables.com/F59/VQGE/GJ7MLXNJ/F59VQGEGJ7MLXNJ.LARGE.jpghttp://cdn.instructables.com/FM6/E3SU/GJ7MLXHA/FM6E3SUGJ7MLXHA.LARGE.jpghttp://cdn.instructables.com/F59/VQGE/GJ7MLXNJ/F59VQGEGJ7MLXNJ.LARGE.jpghttp://cdn.instructables.com/F0S/TBJF/GJ7MLXHB/F0STBJFGJ7MLXHB.LARGE.jpghttp://cdn.instructables.com/FM6/E3SU/GJ7MLXHA/FM6E3SUGJ7MLXHA.LARGE.jpghttp://cdn.instructables.com/FM6/E3SU/GJ7MLXHA/FM6E3SUGJ7MLXHA.LARGE.jpghttp://cdn.instructables.com/F59/VQGE/GJ7MLXNJ/F59VQGEGJ7MLXNJ.LARGE.jpg


9/12
http://cdn.instructables.com/F0S/TBJF/GJ7MLXHB/F0STBJFGJ7MLXHB.LARGE.jpghttp://cdn.instructables.com/FH7/S6P1/GJ7MLXM6/FH7S6P1GJ7MLXM6.LARGE.jpghttp://cdn.instructables.com/F0S/TBJF/GJ7MLXHB/F0STBJFGJ7MLXHB.LARGE.jpghttp://cdn.instructables.com/FH7/S6P1/GJ7MLXM6/FH7S6P1GJ7MLXM6.LARGE.jpghttp://cdn.instructables.com/F0S/TBJF/GJ7MLXHB/F0STBJFGJ7MLXHB.LARGE.jpghttp://cdn.instructables.com/FOM/S9OB/GJ7MLXMQ/FOMS9OBGJ7MLXMQ.LARGE.jpghttp://cdn.instructables.com/FH7/S6P1/GJ7MLXM6/FH7S6P1GJ7MLXM6.LARGE.jpghttp://cdn.instructables.com/FH7/S6P1/GJ7MLXM6/FH7S6P1GJ7MLXM6.LARGE.jpghttp://cdn.instructables.com/F0S/TBJF/GJ7MLXHB/F0STBJFGJ7MLXHB.LARGE.jpg


10/12

Show All 18 Items

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 thecontrol unit keeping its wiring harness as long as possible. The harness

has 5 wires going into the motor housing. By tracing this harness, startingfrom 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 theterminal block. De-solder the grey, orange and red wires at the speedselector, note their location first. (You may have noticed that I cut thewhole harness about 10cm from the motorbig 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 rodaway from the control unit.

4. Remove the oscillating unit and detach the capacitor.
http://cdn.instructables.com/FOM/S9OB/GJ7MLXMQ/FOMS9OBGJ7MLXMQ.LARGE.jpghttp://www.instructables.com/id/FAN-repair/?ALLSTEPS#more-anchorhttp://cdn.instructables.com/FOM/S9OB/GJ7MLXMQ/FOMS9OBGJ7MLXMQ.LARGE.jpghttp://www.instructables.com/id/FAN-repair/?ALLSTEPS#more-anchorhttp://cdn.instructables.com/FOM/S9OB/GJ7MLXMQ/FOMS9OBGJ7MLXMQ.LARGE.jpg


11/12

5. Remove the metal housing screws. Carefully remove the rotor and thewindings 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 noticewhere it ends.

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

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

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

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

11. Notice that one of the fuses leads is also sheathed to prevent electricalcontact. Slice the SIDE of this sheath lengthwise about 10mm. Expose thelead 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 removedin step #10 above.

17. String the new fuse assembly to the windings as neat as you can. Foldback the black cover and string again. Ensure no string or black coversheath 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


12/12

is needed here.

21. Dress back the wiring harness and reconnect the Ground and Neutralwires 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 theoscillator 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 fornearly 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 awhile.

electric fan repair

Documents