Lasko or Air King fan suddenly stops working.
I just figured this out with the help of a local electric motor repair shop (thanks Portty) and thought I share the information since it seems to be a common problem but no one has directly addressed it. Never by pass safety mechanisms! Replace them at your own risk and use your head!
If your fan suddenly stops working (as opposed to taking longer and longer to start turning) it is likely that one of the two main safety systems has been triggered. It's hard to know if it's the safety plug or a thermal fuse in the motor. These are two likely causes for your fan stopping working.
The safety plug, as I understand, has a standard fuse that trips when the current flow gets above some threshold (I suspect the threshold varies between models). For example, my 16" window fan is listed as using 0.8 Amps so they likely used a 1 or 3 Amp fuse in the plug. If the current goes above that it means something is wrong and so, as a safety measure it cuts the current, permanently. You can create your own, fixable alternative by replacing the plug and putting an inline fuse into the power cord above the plug. I would try to find a fuse that is not easy to open since you'll be exposing 120V when it is open.
A second possible cause is the thermal fuse that is located in the motor. This fuse triggers when the motor gets above its normal operating temperature. I've seen references for a 115C cut off, but I don't know for sure what it's threshold temp. is and, again may vary between models. There are numerous YouTube and Instructables that describe how to replace the thermal fuse. For my window fan, I had to disassemble the entire motor in order to able to replace the fuse. Be careful when soldering the new fuse not to overheat the fuse or else you'll blow it and have to put another one in.
More importantly, the fact that either one of these safety systems were triggered means there something wrong with your fan and you'll want to fix that before you restore the tripped safety feature.
One possible and common cause is the motor running out of lubricant. The motor spindle should turn freely when the fan is unplugged. Nice and smooth and very little effort when the blades are removed. If it is stiff, try oiling the axle at both ends. There are some small holes near where the axle comes out that is designed for oiling the motor. Try adding oil there, spin the motor, pull it back and forth, oil some more, repeat until it turns smoothly. Don't worry about using too much oil, you can just wipe any excess off once it starts turning easily.
#lasko #safety_plug #thermal_fuse #air_king
on Jun 10, 2015 | Lasko Dryers