Dehumidifier not working - suspect fault in fan motor; easy fix?

[seanspotatobusiness]

My grandmother's dehumidifier isn't working. It sounds to me as though the refrigeration system is still working normally, but the fan doesn't rotate. I took a photo of the motor. I don't have my multimeter available, though I suppose I could get one.

The motor looks very strange. I don't know why it has fins and heat-tubes. Don't see why it would get that hot. A weird bit on the motor is wrapped in yellow plastic and its sticker includes the code WT-15D1-02 but I can't find anywhere selling such motors on the Internet. I think if I can just make the blades turn at a reasonable speed, the function of the machine will be largely restored. What is the thing wrapped in yellow plastic?

 

[CocaCola]

Check for a fuse or thermal reset on the fan or on the fan wires, it might have popped...

If you can't find one of those you can take a multimeter and test the leads of the fan and see if you are getting power, it should be 220-240 VAC mains voltage so mind your safety...

If you are getting power to the fan and it's not running, something is wrong... The Love Star company is a large volume OEM manufacture so you likely won't find a replacement without contacting an authorized repair center for your unit and having them order in the part... It's likely a stock motor but the part number is almost certainly an OEM rebrand number so cross referencing it will be complicated, thus the reason I suggest an authorized repair center...

And last but not least you might be able to take the fan out of the unit, and soak it the shaft area with WD-40 while spinning the fan, and repeatably soaking it to wash out any grime, it might very well just be gummed up... If the rotating of the fan gets noticeably smoother after a WD-40 treatment, you can wipe off all the excess, and possibly let it sit for a bit to drip dry... Install it and see if that fixed the issue...

 

[duke37]

Shaded pole motors such as this run hot and the output bearing can seize. If the motor appears stiff then it may be possible to strip it and clean the bearing.

If you do dismantle, rebuild the same way or the motor will run backwards.

 

[debe]

On the right hand side of the motor where the red wire goes into the plastic & comes out again, you will probably find a thermal fuse is blown.

 

[seanspotatobusiness]

The fan turns very easily, so I don't think it's seized up. I've looked, and unravelled some of the yellow tape which wraps a coil whose function I can't determine. I can't see any thermal fuse in there but maybe it's somewhere else that I can't see.

I don't understand why it uses a motor assembly rated at 240 volts? Bear in mind that I know relatively little about electronics, but since the motor is actually connected to a PCB, a step-down has obviously occurred somewhere - they might as well have just an ordinary low voltage DC motor in there?

I'm going away now to read about "shaded pole motors". Thank you both for your insight!

 

[seanspotatobusiness]

On the right hand side of the motor where the red wire goes into the plastic & comes out again, you will probably find a thermal fuse is blown.

I missed this message. I had a feel along the wire close to that point, and shrouded in heat-shrink was a small piece which was much harder than the rest. I uncovered it and found what appears to be a thermal fuse. I will need to confirm that it's blown (no multimeter to hand but maybe I can jury rig a continuity tester) and then find out what to replace it with.

 

[CocaCola]

but since the motor is actually connected to a PCB, a step-down has obviously occurred somewhere -

False assumption, the board could still be passing mains voltage to the motor...

 

[(*steve*)]

they might as well have just an ordinary low voltage DC motor in there?

They might have, but they didn't. There are some very obvious signs that this is a shaded pole motor. When you've read up on them, you'll be able to recognise them too.

There is no reason (typically) to run them from anything other than mains voltage.

As confirmation, I would expect the dehumidifier to specify a quite restricted range of input voltages and *not* to have a switch that allows you to select (say) 110/220V operation.

 

[seanspotatobusiness]

Hi. I want to connect my new thermal fuse but I don't know how. I can't solder it because that will probably blow or at least damage the fuse, even with heat sinking. I'm not sure crimping will work because I need to connect the insulated wire of the stator coil to a leg of the thermal fuse. The insulation on the stator coil wire is so thin, I don't think I can strip it?

 

[davelectronic]

If your very light handed you could strip enough insulation off with a very sharp utility / craft knife at 90 degrees to the wire so scraping action, then a mechanical crimp is really the best option, on another thought i would be asking why it popped the thermal fuse, and if to replace the motor instead, as the fault is unknown and for total safety if it where me i would replace the motor.