|Moderated by: Steve Cunningham, Stan Adams, Rod Rogers|
|Hello Everyone, I recently acquired a Westinghosue Lively Aire and it seemed to be running fine until I left it on for 5 minutes.
It started blowing smoke out. I unplugged it. Today, i tested it again and found the smoke is coming from the stator windings. They are very hot on each side and some electric tape is melted.
Also, right before I touched the fan, and felt high static electricity about to shock me.
The fan still works but I dont want to burn it out fully.
Should I try the red spray varnish? Or are the coils fried and need rewound ?
The ohmmeter seems to jump from 15ohms-60ohms when I apply it across the motor...
Thanks everyone !!
|If the stator winding got hot enough to smoke and melt the tape in 5 minutes, it is probably in need of a rewind. The fluctuating resistance is further evidence that the winding insulation is bad and there are turn-to-turn shorts.
Thank you for the input. I have decided to rewind the fan stator and try to do it myself for the first time.
I would like to post pictures on here and show my progress.
First here are some photos of the fan:
Everything works fine except it gets really hot and the stator coils start smoking... haha
Rotor just a little dirty. It rotates smooth
Now for the stator coils...
The stator I have looks just like this one taken from here (I forgot to photo mine). One coil on each side, with wire running on bottom between them.
The coils were smoking hot and melting some of the wire/electric tape that was put on it.
Now my stator looks like this after a little hacking :
I was able to measure the following specs:
1) about 600 turns each coil (counted the pieces of coil section...)
2) about 22 AWG wire (less than .5mm diameter wire... it might by 23 AWG... )
This amounts to about 600feet of 22AWG wire total for 2 coils.
2inch x 1.5inch approx size coil in outer turns.
7 inch per coil in outer, 5 inch per turn on inner.
so average 3600 inches per coil .
300 ft per coil.
600 ft total for 2 coils.
I will probably purchase 600-700 ft of 22AWG wire. $25-$30
Above I show my drawing of how I think the coil was wound up.
Looking at the stator from the right side (front fan side is to the right). The wire lead comes in from the top, then is wound clockwise,( enter towards front on top, and come back toward backside on bottom).
Looking at the stator from the left side (front fan side is to the left). I think the wire comes in from first coil on bottom, then is wound counter-clockwise, enter toward front on bottom, and come back toward backside on top. Wire exits on top to make 2nd lead.
Looking from back side (toward front):
1) Wire enters top right (lead 1)
2) Wire comes back bottom right
3) Wire turns 600 times
4) Wire exits bottom and connects to left bottom
5) Wire enters bottom left.
6) Wire comes back top left
7) Wire turns 600 times
8) Wire exits top left (lead 2)
Now I am not sure how to make the coils.
I assume that I have to make them, then somehow get them onto the stator. Or wind them on the stator which seems would be difficult if not impossible.
I also am not sure if I need this hard insulating fabric over the coils when I am finished.
For now I am going to inspect the stator and see if a piece comes off to put new coils onto it.
|I found that two pieces can tap out of the stator. Unlocking all the secrets! haha
Next step will be to research the wire a little more, and figure out a fixture to make a tight coil.
|Al Blake wrote:
I found that two pieces can tap out of the stator. Unlocking all the secrets! haha
Hi Al. That's looking good!
For the wire, you'll want to measure the diameter of the wire with a caliper. There are charts which show how many thousandths in diameter each wire gauge is. You'll probably find it's a little in between, but you can get a size which is close. If it's dead-center in between two sizes, go smaller or the coil may not fit in the motor (voice of experience!).
When you order the wire, order "200C" or "Class F" wire. This is a very high temperature wire and will not degrade over time at normal operating temperature, as the original did.
There are supposed ot be paper "liners" in the slots of the stator core. These keep the winding from getting cut and shorting out by the iron sheets making up the lamination. For this, order Nomex paper.
For the new stator lead wires, you can get Teflon insulated wire which has a nice, thin profile and will not be bulky and hard to integrate into the coil.
Finally, to wrap the coils and hold them in the shape they need to be; you'll want Kapton tape.
And, finally, to seal and secure everything, a coating of Class F rated varnish will top it all off!
I'm no expert and have only rewound one motor. It was a 4-pole unit with removable coils.
With this type motor, the direction the motor runs is set by the shading coils. These are the copper bands which are in the stator after the winding was removed. If these are flipped around the wrong way, the motor will run backwards.
Here is a video about my first and only attempt at a rewind: https://www.youtube.com/watch?v=xjxLlDxgxKg
|Well I think I have it fixed. Still need to add heat shrink and solder it better.
I purchased :
1) 785 ft of 27 AWG magnet wire. $19
2) Kapton tape 13mm 100 ft. $6
3) Nomex paper 10 mil 4inch x 11 inch $6
First I measued the wire using a caliper, it was 0.35mm diameter, around 27 AWG wire.
I made this manual rig for winding the coils. Each coil is 600 turns (12 rounds of 50 turns is what I did manually).
It has 4 screws with plastic electrical caps in between the two pieces of wood.
The size of the coil was not correct at first and I wasted alot of wire. I actually had to purchase a 2nd 785ft coil of magnet wire because I messed it up. Next time, I would use a little wire to experiment with the right size, making small coils. Then finally create the full coil. So I wouldnt waste any wire next time.
You can see the bad coils I made on the table.
I had to carefully get the coils out and wrap them in kapton.
Also, I had to use two pieces of wood, and a clamp, to press the coil down very tight.
Parts of the coils I had to press with some pliars to make the coil tight enough to fit.
I should seal this coil with varnish to make sure nothing comes loose but I just wanted to get it working for now.
I need to take some close ups of the coils installed.
Basically, I had to carefully fit them into the tight spaces, and use the nomex paper to make sure the coil doesnt rub against the metal anywhere at all.
I also added some paper on the coil sides where it was rubbing against the fan motor body. I need to clean this up a bit.
For the wire connections (for now), all I did was rub the insulating layer off, solder the ends together, then wrap with a little bit of electrical tape. I know this is temporary and need heat shrink for the wires.
So I was very happy when i finally got them into the fan fitting, with the rotor rotating freely.
As a side note, I had to do some circuit troubleshooting, because the rotor didnt turn when I first wired it up.
1) I hooked up multimeter to measure voltage for input/output.
2) When I did this, I noticed the rotor jumped a little bit.
3) I realized my multimeter clip was completing the fan circuit.
4) I resoldered the output connection of the fan. Then I could get the rotor to jump without multimeter.
5) Put the fan top on, and blades. And like magic, it started rotating.
Here it is:
It gets a little hot on the back side.
However, I ran the fan for a few hours and then brought it inside and ran it for 3 hours with the cage on around the blades.
There is no smoke at all, no smells, and inside the fan body doesnt get that hot anymore. I can hold my hand on there easily.
I will upload some more pictures, and also try to make the circuit better with heat shrink. and maybe replace the cord to the wall. Then maybe repaint and clean it all up.
Thank you very much for your help David.
|Wow, I am very impressed. If I possesed your skillset and knowledge of electricity, no fan would ever die or go unrestored. Well done sir! Great save.
|Al Blake wrote:
Well I think I have it fixed. Still need to add heat shrink and solder it better.
Hi Al! I'm delighted you were able to make new coils for your fan! Those look like they will last quite a while. That little motor was built to be rewindable, that's for sure!