So my little 2-speed fan just stops running.

http://harborside-color.amazonwebsto...B000WLVKZG.htm

I workbench it and try to figure what the problem might be. It's
getting power. Nothing appears to be burnt.

Can anyone identify the type of elec. motor in the pics?

http://imageshack.us/photo/my-images...anapart001.jpg

http://imageshack.us/photo/my-images...anapart002.jpg

The pics are the 2 sides of the same motor.

Any info and or hints about the principles of operation of this type
motor would be much appreciated.

TIA,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Puddin' Man wrote:
So my little 2-speed fan just stops running.

http://harborside-color.amazonwebsto...B000WLVKZG.htm

I workbench it and try to figure what the problem might be. It's
getting power. Nothing appears to be burnt.

Can anyone identify the type of elec. motor in the pics?

http://imageshack.us/photo/my-images...anapart001.jpg

http://imageshack.us/photo/my-images...anapart002.jpg

The pics are the 2 sides of the same motor.

Any info and or hints about the principles of operation of this type
motor would be much appreciated.

TIA,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Shaded pole rings a bell. I have had motors like this that lock up on power
up. It would be hard to turn. It should turn freely with no power. If
nothing happens I would suspect open winding.

Greg

On 4/9/2012 11:23 AM, Puddin' Man wrote:

So my little 2-speed fan just stops running.

http://harborside-color.amazonwebsto...B000WLVKZG.htm

I workbench it and try to figure what the problem might be. It's
getting power. Nothing appears to be burnt.

Can anyone identify the type of elec. motor in the pics?

http://imageshack.us/photo/my-images...anapart001.jpg

http://imageshack.us/photo/my-images...anapart002.jpg

The pics are the 2 sides of the same motor.

Any info and or hints about the principles of operation of this type
motor would be much appreciated.

TIA,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."


Well if there is power up to the motor windings then they are probably
open circuit or there is a thermal fuse embedded in the windings which
has gone open. You may be able to dig it out or bridge it at your risk.

Puddin' Man wrote:

So my little 2-speed fan just stops running.

http://harborside-color.amazonwebsto...B000WLVKZG.htm

I workbench it and try to figure what the problem might be. It's
getting power. Nothing appears to be burnt.

Can anyone identify the type of elec. motor in the pics?

http://imageshack.us/photo/my-images...anapart001.jpg

http://imageshack.us/photo/my-images...anapart002.jpg

The pics are the 2 sides of the same motor.

Any info and or hints about the principles of operation of this type
motor would be much appreciated.

http://en.wikipedia.org/wiki/Shaded-...chronous_motor

Search on "shaded pole motor".

More info please?
How long does it run before it stops?
About what speed does it run? About 3400 RPM?
Does it stop abruptly or does it slow down and then stop?
Does it stop when you move the various wiring bits?

--Winston

On Sun, 08 Apr 2012 23:46:18 -0700, Winston wrote:

http://en.wikipedia.org/wiki/Shaded-...chronous_motor

Search on "shaded pole motor".

Thanks for ID. Interesting, but over my head. :-(

More info please?
How long does it run before it stops?
About what speed does it run? About 3400 RPM?
Does it stop abruptly or does it slow down and then stop?
Does it stop when you move the various wiring bits?

Purchased ~ 4 years ago.
Used extensively mostly in summer of 2011 (maybe 10 hours/day).
Made strange sympathetic vibration sound, ~C#.
Worked OK about 3 weeks ago.
Stopped functioning altogether.

The shaft turns freely. No evidence of a heat problem.
Gets 120v thru feed wires.
No contacts on coil (cannot test voltage there).
Just sits there and looks dumb when powered.

Can't find -any- specs on it (Model MH-20UL)

Chinee wonder mystery, probably not worth further consideration?

Thx,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Puddin' Man wrote:

So my little 2-speed fan just stops running.

http://harborside-color.amazonwebsto...B000WLVKZG.htm

I workbench it and try to figure what the problem might be. It's
getting power. Nothing appears to be burnt.

Can anyone identify the type of elec. motor in the pics?

http://imageshack.us/photo/my-images...anapart001.jpg

http://imageshack.us/photo/my-images...anapart002.jpg

The pics are the 2 sides of the same motor.

Any info and or hints about the principles of operation of this type
motor would be much appreciated.

TIA,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

You have a shaded pole motor..

check the spindle slop or stiffness.

You don't want either.

also, did you recently spray this down with parts clearer of
something? Does the core seem to get hot to you?

If yes to either, trash it.

Jamie

Puddin' Man wrote:

On Sun, 08 Apr 2012 23:46:18 -0700, Winston wrote:

http://en.wikipedia.org/wiki/Shaded-...chronous_motor

Search on "shaded pole motor".

Thanks for ID. Interesting, but over my head. :-(

More info please?
How long does it run before it stops?
About what speed does it run? About 3400 RPM?
Does it stop abruptly or does it slow down and then stop?
Does it stop when you move the various wiring bits?

Purchased ~ 4 years ago.
Used extensively mostly in summer of 2011 (maybe 10 hours/day).
Made strange sympathetic vibration sound, ~C#.
Worked OK about 3 weeks ago.
Stopped functioning altogether.

The shaft turns freely. No evidence of a heat problem.
Gets 120v thru feed wires.
No contacts on coil (cannot test voltage there).
Just sits there and looks dumb when powered.

Can't find -any- specs on it (Model MH-20UL)

Chinese wonder mystery, probably not worth further consideration?


Do you have continuity through the winding? If not, then there is a
thermal fuse somewhere inside the motor. Usually, right under the point
where the wires enter the motor. If there are terminals, look and see
what size & type wire goes from them. If one is larger than the other,
that will be a lead from the fuse.


--
You can't have a sense of humor, if you have no sense.

Michael A. Terrell wrote:

Puddin' Man wrote:

(...)

Purchased ~ 4 years ago.
Used extensively mostly in summer of 2011 (maybe 10 hours/day).
Made strange sympathetic vibration sound, ~C#.

'Sounds like a failed bearing.

Worked OK about 3 weeks ago.
Stopped functioning altogether.

The shaft turns freely. No evidence of a heat problem.
Gets 120v thru feed wires.

As Michael mentioned, presenting 120 V to the coil does
not necessarily mean there is current through the coil.




No contacts on coil (cannot test voltage there).
Just sits there and looks dumb when powered.

Can't find -any- specs on it (Model MH-20UL)

Chinese wonder mystery, probably not worth further consideration?

'Probably true. Please use your multimeter to measure the resistance
of the switch when on, wires, connectors etc.

As Michael implies, your first - order test would be a resistance
measurement from prong to prong on the unplugged A.C. connector.

If it is 'open' and the switch and power cable tested OK, you're
probably not going to be able to repair the motor economically.
It is your call whether you want to unwrap the winding to discover
an open fuse as a matter of edification and entertainment,
before you throw it away.

If you are really economical (as I can be), you can salvage a low-
mileage shaded-pole motor out of a scrapped microwave oven and
use that in your fan. I see four in my scrap box from where
I'm sitting!

Shaft adapters are left as an exercise.

Do you have continuity through the winding? If not, then there is a
thermal fuse somewhere inside the motor. Usually, right under the point
where the wires enter the motor. If there are terminals, look and see
what size& type wire goes from them. If one is larger than the other,
that will be a lead from the fuse.


--Winston-- Salvage Safely! Some components can maintain sufficient
charge to knock you on your keester.

On Mon, 09 Apr 2012 17:31:39 -0700, Winston wrote:

Michael A. Terrell wrote:

Puddin' Man wrote:

(...)

Purchased ~ 4 years ago.
Used extensively mostly in summer of 2011 (maybe 10 hours/day).
Made strange sympathetic vibration sound, ~C#.

'Sounds like a failed bearing.

I doubt it. It made that sound all summer. No evidence of a burnt
bearing. No play in the fan shaft.

Worked OK about 3 weeks ago.
Stopped functioning altogether.

The shaft turns freely. No evidence of a heat problem.
Gets 120v thru feed wires.

As Michael mentioned, presenting 120 V to the coil does
not necessarily mean there is current through the coil.

Understood.

No contacts on coil (cannot test voltage there).
Just sits there and looks dumb when powered.

Can't find -any- specs on it (Model MH-20UL)

Chinese wonder mystery, probably not worth further consideration?

'Probably true. Please use your multimeter to measure the resistance
of the switch when on, wires, connectors etc.

As Michael implies, your first - order test would be a resistance
measurement from prong to prong on the unplugged A.C. connector.

If it is 'open' and the switch and power cable tested OK, you're
probably not going to be able to repair the motor economically.

Such is the case.

It is your call whether you want to unwrap the winding to discover
an open fuse as a matter of edification and entertainment,
before you throw it away.

If you are really economical (as I can be), you can salvage a low-
mileage shaded-pole motor out of a scrapped microwave oven and
use that in your fan. I see four in my scrap box from where
I'm sitting!

Shaft adapters are left as an exercise.

All of that is well beyond me.

I don't even know how to properly test because I
don't understand the wiring. :-(

Spare a minute? I comprehend that I can wrap wires around a conductor, apply
current, and have an electromagnet. If I can time the switching of polarity,
and place the em in the field of a fixed magnet, I'll have basic components
of an elec. motor. No?

Alternatively, I could have + and - fields formed with the em, and have a
fixed magnet as an armature (??) thus constituting a "motor".

But I'm still miles from understanding how this shaded pole motor works.
It looks like it has a big fixed magnet (but with copper tubes running
around it), a large winding presumably between the N and S poles, and
a separate armature (with fan shaft) in the middle of the fixed magnet.
This describes what I see in the pics.

If you can explain how these components relate to my miniscule understanding
of the basic components of a "motor" (above), I would award you with a
(virtual) "Cigar And A Beer". :-) I'm obviously missing a bunch. Hope I
haven't mangled the terminology too badly.

Thanks,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Puddin' Man wrote:
On Mon, 09 Apr 2012 17:31:39 -0700, wrote:

Michael A. Terrell wrote:

Puddin' Man wrote:

(...)

Purchased ~ 4 years ago.
Used extensively mostly in summer of 2011 (maybe 10 hours/day).
Made strange sympathetic vibration sound, ~C#.

'Sounds like a failed bearing.

I doubt it. It made that sound all summer. No evidence of a burnt
bearing. No play in the fan shaft.

Worked OK about 3 weeks ago.
Stopped functioning altogether.

The shaft turns freely. No evidence of a heat problem.
Gets 120v thru feed wires.

As Michael mentioned, presenting 120 V to the coil does
not necessarily mean there is current through the coil.

Understood.

No contacts on coil (cannot test voltage there).
Just sits there and looks dumb when powered.

Can't find -any- specs on it (Model MH-20UL)

Chinese wonder mystery, probably not worth further consideration?

'Probably true. Please use your multimeter to measure the resistance
of the switch when on, wires, connectors etc.

As Michael implies, your first - order test would be a resistance
measurement from prong to prong on the unplugged A.C. connector.

If it is 'open' and the switch and power cable tested OK, you're
probably not going to be able to repair the motor economically.

Such is the case.

It is your call whether you want to unwrap the winding to discover
an open fuse as a matter of edification and entertainment,
before you throw it away.

If you are really economical (as I can be), you can salvage a low-
mileage shaded-pole motor out of a scrapped microwave oven and
use that in your fan. I see four in my scrap box from where
I'm sitting!

Shaft adapters are left as an exercise.

All of that is well beyond me.

I don't even know how to properly test because I
don't understand the wiring. :-(

Series circuit. AC hot to switch, from switch to motor,
from motor to AC neutral, pretty much.
That is what you see, yes?

Spare a minute? I comprehend that I can wrap wires around a conductor, apply
current, and have an electromagnet. If I can time the switching of polarity,
and place the em in the field of a fixed magnet, I'll have basic components
of an elec. motor. No?

See below.

Alternatively, I could have + and - fields formed with the em, and have a
fixed magnet as an armature (??) thus constituting a "motor".

But I'm still miles from understanding how this shaded pole motor works.
It looks like it has a big fixed magnet (but with copper tubes running
around it), a large winding presumably between the N and S poles, and
a separate armature (with fan shaft) in the middle of the fixed magnet.
This describes what I see in the pics.

If you can explain how these components relate to my miniscule understanding
of the basic components of a "motor" (above), I would award you with a
(virtual) "Cigar And A Beer". :-) I'm obviously missing a bunch. Hope I
haven't mangled the terminology too badly.

Please review the results of your Internet
searches WRT motors in general and shaded pole motors
in particular. I expect some have very illuminating
illustrations and perhaps a cartoon or two.

My understanding of these things is marginal
at best, so I hereby bump your question to
those more knowledgeable and articulate.



--Winston

On Tue, 10 Apr 2012 17:16:54 -0700, Winston wrote:

I don't even know how to properly test because I
don't understand the wiring. :-(

Series circuit. AC hot to switch, from switch to motor,
from motor to AC neutral, pretty much.
That is what you see, yes?

No. All I'm really familiar with is common house wiring. 3
wires, black (and maybe red), white, and bare (or green).
Connect black and white to device, close circuit, device
runs (if functional). 120v potential between black and
white. 240v between black and red (?).

Per the pics, shaded pole is wired red, black, and
blue. Where is Common?

Thx,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

"Puddin' Man" wrote in message
...
On Tue, 10 Apr 2012 17:16:54 -0700, Winston
wrote:

I don't even know how to properly test because I
don't understand the wiring. :-(

Series circuit. AC hot to switch, from switch to motor,
from motor to AC neutral, pretty much.
That is what you see, yes?

No. All I'm really familiar with is common house wiring. 3
wires, black (and maybe red), white, and bare (or green).
Connect black and white to device, close circuit, device
runs (if functional). 120v potential between black and
white. 240v between black and red (?).

Per the pics, shaded pole is wired red, black, and
blue. Where is Common?

Thx,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."


Its probably a tapped coil to provide two speeds. In this case, Black is
"common" to both speeds (not necessarily neutral but it probably is
connected to the neutral side of the cord), Red and Blue represent two
speeds, fed by the switch, which in turn is fed from the mains side of the
cord. Test ohms from Black to red, and from Black to blue; they should have
some value other than 0 or infinity.

It has been mentioned before in this thread that the most common failure is
in the brass slip bearings often used in these things. The tiniest bit of
uneven wear will allow the rotor to lock to the stator.
If it locks up when powered, suspect the bearing.
If it spins free when powered, suspect the switch or the motor.
If it spins when powered or hums, but seems to have reluctance, suspect the
motor.

Scott

On Thu, 12 Apr 2012 17:20:41 -0500, "Anon" wrote:

Its probably a tapped coil to provide two speeds.

I ran a search on "tapped coil": wasn't much help. Howzit woik?

In this case, Black is
"common" to both speeds (not necessarily neutral but it probably is
connected to the neutral side of the cord), Red and Blue represent two
speeds, fed by the switch, which in turn is fed from the mains side of the
cord. Test ohms from Black to red, and from Black to blue; they should have
some value other than 0 or infinity.

Unplugged. Black to red: 0. Black to blue: 0. Blue to red: 1.

Found more info:

Thermo-fuse Rot CW
|--------- Black --------------------------
| |
|--------- Blue (Lo) ---------- Line
| |
|----------Red (Hi) -----------------------

It has been mentioned before in this thread that the most common failure is
in the brass slip bearings often used in these things. The tiniest bit of
uneven wear will allow the rotor to lock to the stator.

Not observed.

If it locks up when powered, suspect the bearing.
If it spins free when powered, suspect the switch or the motor.
If it spins when powered or hums, but seems to have reluctance, suspect the
motor.

It just stopped running. Shaft turned freely.

I'm not really concerned about this motor. I just *hoped* to understand
something of it's electromagnetic workings and how that related to the
wire colors, etc.

Thx,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

"Puddin' Man" wrote in message
...
On Thu, 12 Apr 2012 17:20:41 -0500, "Anon" wrote:

Its probably a tapped coil to provide two speeds.

I ran a search on "tapped coil": wasn't much help. Howzit woik?

In this case, Black is
"common" to both speeds (not necessarily neutral but it probably is
connected to the neutral side of the cord), Red and Blue represent two
speeds, fed by the switch, which in turn is fed from the mains side of the
cord. Test ohms from Black to red, and from Black to blue; they should
have
some value other than 0 or infinity.

Unplugged. Black to red: 0. Black to blue: 0. Blue to red: 1.

Found more info:

Thermo-fuse Rot CW
|--------- Black --------------------------
| |
|--------- Blue (Lo) ---------- Line
| |
|----------Red (Hi) -----------------------

It has been mentioned before in this thread that the most common failure
is
in the brass slip bearings often used in these things. The tiniest bit of
uneven wear will allow the rotor to lock to the stator.

Not observed.

If it locks up when powered, suspect the bearing.
If it spins free when powered, suspect the switch or the motor.
If it spins when powered or hums, but seems to have reluctance, suspect
the
motor.

It just stopped running. Shaft turned freely.

I'm not really concerned about this motor. I just *hoped* to understand
something of it's electromagnetic workings and how that related to the
wire colors, etc.

Thx,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."


"Rot CW" means it was design to rotate Clockwise.
"Thermo fuse" means it has a thermal fuse that would open when it gets too
hot.

Black and Red are the ends of the primary coil. The Blue wire is either
"tapped" off the coil (some number of turns) short of Red end, or is wound
as a smaller secondary coil. Black to Blue provides a weaker magnetic field
for Low speed. From your Ohm readings it appears there is a break in the
primary coil or Black wire connection, likely the thermal fuse wound into
the coil.

When the sine wave of 120V Alternating Current is fed into the coil, the
steel core is magnetized, reversing N-S poles at 60 Hz. The arrangement of
copper "tubing" inserted the steel core provides a secondary/induced
magentic field in the core, lagging behind the primary coil's sine wave.
This is the "shaded pole". The phase difference in the primary sine wave
and the induced shaded pole drive the rotor around.

A shaded-pole motor is a type of induction motor.

Scott
Dunedin, FL

On Mon, 16 Apr 2012 10:48:42 -0500, "Anon" wrote:

"Rot CW" means it was design to rotate Clockwise.
"Thermo fuse" means it has a thermal fuse that would open when it gets too
hot.

Black and Red are the ends of the primary coil. The Blue wire is either
"tapped" off the coil (some number of turns) short of Red end, or is wound
as a smaller secondary coil. Black to Blue provides a weaker magnetic field
for Low speed. From your Ohm readings it appears there is a break in the
primary coil or Black wire connection, likely the thermal fuse wound into
the coil.

When the sine wave of 120V Alternating Current is fed into the coil, the
steel core is magnetized, reversing N-S poles at 60 Hz.

Thank you.

The arrangement of
copper "tubing" inserted the steel core provides a secondary/induced
magentic field in the core, lagging behind the primary coil's sine wave.
This is the "shaded pole".

Thank you, again.

The phase difference in the primary sine wave
and the induced shaded pole drive the rotor around.

A shaded-pole motor is a type of induction motor.

This is the sort of explanation I sought.

Many thanks,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."