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[standfaninformationposts-blog]

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.

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)

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.

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.

[standfaninformationposts-blog]

How to Repair an Electric Fan

Unplug the fan and either unhook the blade guard or unscrew the pin. Pull the fan’s electrical cord out to keep it from turning on randomly while you’re working on it. Feel around the sides of the blade guards for clips that are holding the 2 parts together. If there are clips, unhook them and remove the front half. If you don’t see any hooks keeping the blade assembly together, try turning the circular center of the fan counterclockwise. If it loosens, unscrew it and set the front of the blade case down.[2]The pin is the piece of metal in the center of the fan that the blades and case rotate around.The blade guard, or blade casing, refers to the plastic or metal case that keeps people from getting hurt by the blades. On most fans, it either holds together with clips where the 2 pieces meet, or it relies on a cap in the middle to keep the case screwed tight.If you see screws holding the case together, unscrew them with a screwdriver to remove the case that way.Whether the blades aren’t spinning or the fan is making tons of noise, most issues with an electric fan are caused by poor lubrication or blockages in the vents. To solve most problems with an electric fan, disassemble the fan, lubricate the central pin and bearings, and clean out the vent and motor case. Repairing an electric fan can be tough if the problem has anything to do with the motor itself, which may be dead if the fan makes no noise when it’s turned on and the blades don’t turn at all after cleaning and oiling the pin. Since electric fans tend to be inexpensive, it’s usually not worth it to bother trying to repair the motor on your own and you should consider simply buying a new fan.

Part 1 Disassembling the Fan

Turn your fan on to make sure that the motor works. Plug your fan in and turn it on to the highest power setting. If the fan blades move a little or it starts to turn, the motor is probably still good. If you don’t hear anything, put your ear up to the middle of the case behind the blades. Press the button to turn the fan off and on again, this time listening closely for the motor. If you hear it humming or buzzing, your motor is likely still functioning.[1] Check the fan in multiple outlets. It’s possible that the circuit breaker on an outlet was flipped and the fan simply wasn’t getting an electrical signal. Tip: For most table and standing fans, it won’t be worth it to tinker with the engine to try and get it to start again. The motor is probably dead anyway. You’re better off just buying a new fan if the engine isn’t firing. Feel free to disassemble the engine if you really want to try it yourself though!

Unplug the fan and either unhook the blade guard or unscrew the pin. Pull the fan’s electrical cord out to keep it from turning on randomly while you’re working on it. Feel around the sides of the blade guards for clips that are holding the 2 parts together. If there are clips, unhook them and remove the front half. If you don’t see any hooks keeping the blade assembly together, try turning the circular center of the fan counterclockwise. If it loosens, unscrew it and set the front of the blade case down.[2] The pin is the piece of metal in the center of the fan that the blades and case rotate around. The blade guard, or blade casing, refers to the plastic or metal case that keeps people from getting hurt by the blades. On most fans, it either holds together with clips where the 2 pieces meet, or it relies on a cap in the middle to keep the case screwed tight. If you see screws holding the case together, unscrew them with a screwdriver to remove the case that way.

Turn the blades or washer in the center of the fan counterclockwise to remove them. Every fan is different, but the blades are either locked in place with a small washer on the pin or by the case of the pin itself. If there is plastic blocking the center of the blades, twist it counterclockwise until it comes loose and slide the blades off. If there is no washer, twist the base of the blades while holding the pin in place to loosen them off of the pin.[3] Depending on the model of your fan, there may be a latch on the side of the pin locking the blades into place. This latch usually slides back and forth to lock or unlock the blades.

Slide the back half of the blade guard off of the pin in the center.

Remove any plastic or metal washers that are in front of the back half of the blade guard first. You may need to unscrew a few screws to access the back half. Remove any washers and slide the back half of the blade guard all the way off of the pin.

If there was a plastic washer in front of the blades themselves, then there likely won’t be a washer in the back. If there wasn’t a plastic washer in the front, it’s highly likely that it’s in the back. The washer usually acts as a stabilizer to hold the blades in place.

If there’s some plastic cover or case on front of the motor, unscrew the plate blocking the body of the motor.

[standfaninformationposts-blog]

How to Repair a Stand Fan

Typically, the more reliable components of a stand fan are the base, fan and motor. Conversely, the more unreliable components are the height and angle-adjustment mechanisms on the tube of a pedestal fan. A broken fan-blade assembly is easily replaced with a new one. If the motor is noisy or doesn't work, you should take the fan to a repair shop. Repairing a wobbly tube or worn adjustment mechanisms that don't remain tight is not difficult. In a short time, your fan will be circulating the air to your liking.

1

Unplug the power cord for the stand fan from the electrical outlet.

2

Tighten the screws that secure the circular flange at the lower end of the tube to the top of the base, using a screwdriver. If the lower end of the tube fits into the base, tighten the large locknut at the base of the tube with adjustable pliers.

3

Loosen the height-adjustment knob at the tube and allow the fan to lower to the lowest setting. Fully loosen the knob and pull the knob and attached threaded stem out of the bracket at the tube.

4

Slide a lock washer onto the end of the threaded stem and against the base of the knob. Insert the stem into the bracket and stop when the end of the stem is in the gap between the inner edges of the bracket. Fit a lock washer onto the end of the stem at the gap. Screw the stem fully into the bracket using the knob. Raise the fan to the desired height and tighten the knob.

5

Ask an assistant to hold the fan steady to fix the angle-adjustment for the fan. Loosen the adjustment knob and pull the knob and attached threaded stem out of the adjustment bracket. Repeat the previous step to install two lock washers on the stem, and tighten the knob.