Fan Repair

Joshua R. T. Purba

2024-01-28

I have a pedestal/standing fan I bought in 2016. It is Cosmos 16-SDB. As the name suggests it is a 16 inches (40.64cm) diameter fan. Over the years it frequently slowed down, sometimes even stalled, the AC motor became hot, and made disturbing squeaky noises. Usually when this happened I disassembled it, cleaned it, and oiled the bearings. Sometimes I also cleaned the old grease in the gearbox and re-apply new grease. In 2023 it got bad enough I replaced the bearings, the nylon and stainless steel washers, and the capacitor, all in separate occasions.

Now in January 2024 it stalled again, with even worse noises. I did the usual ritual: disassembly, cleanup, oiled the bearings, re-grease the gearbox. This time though the improvement is much negligible than usual. The AC motor still got hot, the spin still slow (even with the fastest setting). Most importantly the squeaky noises were driving me nuts.

This is the old faulty assembly seen from the side that shows the capacitor. The AC-motor metal covers are grey. — The old AC-motor-and-gearbox assembly.

Same as before but I flipped it to the other side. — Other side of the old assembly.

Same as before but from the top side. There is a sticker that says:<br>HD Motor Model: HD-40 16"<br>220VAC, 50Hz, 50W<br>Specified Speed: 1200 r/min<br>Insulation Grade: E — Top side of the old assembly.

What to do? I checked in local online marketplace: a new replacement AC-motor-and-gearbox assembly (including capacitor) cost only about ⅕ the price of the entire fan when I bought it new in 2016. No brainer here, I bought the replacement assembly 🤑.

The replacement assembly arrived. After a cursory look I concluded that the dimensions matches the old one. Not exact match though, the replacement is about 2mm thinner, and an original screw from the old gearbox needed to be replaced because the screw hole in the new gearbox is larger.

This is the new replacement assembly seen from the side that shows the capacitor. The AC-motor metal covers are yellowish typical of galvanized steel. — The new AC-motor-and-gearbox replacement assembly.

Without further ado I did the replacement.

It is time to separate the old assembly from the switch box. I need to open the switch box first. — The switch box still connected to the old assembly.

The switch box was open showing wires and the rotary switch. This was the only thing that I needed to search because I have never opened this switch box before. — The switch box was opened.

This shows how the wires of the old assembly was soldered to the rotary switch.<br>Grey = Speed 1 (Slow)<br>Orange = Speed 2 (Medium)<br>Red = Speed 3 (Fast)<br>Blue = AC neutral (connect to mains neutral) — The solder lugs side of the rotary switch.

I labeled the switch positions to make the replacement easier.

Instead of simply soldering the replacement assembly wires to the rotary switch, I opted to crimp the old wires with ferrules. I will connect them with the replacement assembly with spring terminals. — After cutting the old wires I crimped them with ferrules.

I crimped the wires from the replacement assembly with ferrules, and then connect them to the old wires using spring terminals. For the replacement assembly:<br>Blue = Speed 1 (Slow)<br>White = Speed 2 (Medium)<br>Red = Speed 3 (Fast)<br>Black = AC neutral (connect with mains neutral) — Connected the old wires with the new assembly using spring terminals.

I immediately tested it after done connecting and before reassembly. It worked. All switch positions worked. No smoke and no squeaky noises. The replacement assembly only got a little warm which is normal. — Testing after connecting. It worked!

I just needed to tidy up the wires with zip ties, and then close the switch box again. — Reassembly with the new assembly.

Same as before but flipped to the other side. The switch box had been closed again. — Reassembly with the new assembly, the other side.

The reassembly was done. Here showing the top of the fan (the pedestal not shown). — Reassembly done.

This shows the fan-blades spin. The photo is a bit blurry because I have to turn off flash to capture the movement of the blades. Everything work fine again. No noises, the fan did not get hot, every position worked, and the side-to-side sweeping motion also works. — It worked after complete reassembly.

It is done. Now my fan works fine again, spins almost like brand new even.

I was surprised by how cheap the replacement assembly was and how easy it was to perform the replacement. The only thing I need to search while doing this was how to open the switch box. This was one of those “everything went as expected” repair project, which is great! Most importantly I am happy my room feels cooler again 😊.

Lastly, this was useful for me:

Wires of old/original assembly	Wires of new/replacement assembly	Rotary switch position	Speed
Gray	Blue	1	Slow
Orange	White	2	Medium
Red	Red	3	Fast
Blue (connect to AC neutral)	Black (connect to AC neutral)	Not connected to switch	N/A

See you later.