Dryer motor smoker

[Ray L. Volts]

Got a GE 4.8A clothes dryer motor here which emitted some smoke one day
shortly after powering it up. I've been using this blower assembly for
solder fume extraction from my bench, so it had no drum loading the
motor down.
I shut it down before the thermal protection kicked in. I then blew all
the dust out that I could get to with an aerosol duster and hooked it up
to a switched, breaker outlet strip outdoors where there would be no
fire hazard (other than to the motor itself) so I could check it out
further.
Powered it up, it ran about 10 secs then smoked again. There was no
duct attached and the bearings turned freely (both before and after the
first smoking event), so it wasn't binding.
Tried it again, this time allowing it to run until the thermal
protection shut it off. After a couple more times powering it up and
letting the thermal protect do its thing, it worked perfectly from then
on – no smoke, no thermal runaway, no noticeable loss in CFM. It
continues to run flawlessly and does not overheat or smoke, even when I
block the inlet to purposely strain the motor.

Question is, what the heck was smoking? If it were dust burning off,
the motor would have had to have gotten hot enough TO burn it off, yet
the first time it only smoked a lot and didn't shut itself down. On the
other hand, if winding varnish were melting off, damaging the motor, why
is there no loss in performance, no more overheating and no signs there
was ever a problem??

I obviously can't trust this motor as I had, even though the thermal
protection does appear to be working properly. This thing would be a
real bitch to disassemble and rewind, though – assuming I can even get
my hands on the right gauges of magnet wire.

So, whaddya think? Should I continue to use this motor and just monitor
it carefully, or should I attempt a rewind just to be on the safe side?
Sure, I could buy another motor ($$$), but as I said, this one IS
working, so I'm not sure replacement is necessary at this point.

Anybody care to share their experience with these motors in terms of
expected lifespan after an overheating incident (or three)?

 

[hr(bob) [email protected]]

Got a GE 4.8A clothes dryer motor here which emitted some smoke one day
shortly after powering it up. I've been using this blower assembly for
solder fume extraction from my bench, so it had no drum loading the
motor down.
I shut it down before the thermal protection kicked in. I then blew all
the dust out that I could get to with an aerosol duster and hooked it up
to a switched, breaker outlet strip outdoors where there would be no
fire hazard (other than to the motor itself) so I could check it out
further.
Powered it up, it ran about 10 secs then smoked again. There was no
duct attached and the bearings turned freely (both before and after the
first smoking event), so it wasn't binding.
Tried it again, this time allowing it to run until the thermal
protection shut it off. After a couple more times powering it up and
letting the thermal protect do its thing, it worked perfectly from then
on - no smoke, no thermal runaway, no noticeable loss in CFM. It
continues to run flawlessly and does not overheat or smoke, even when I
block the inlet to purposely strain the motor.

Question is, what the heck was smoking? If it were dust burning off,
the motor would have had to have gotten hot enough TO burn it off, yet
the first time it only smoked a lot and didn't shut itself down. On the
other hand, if winding varnish were melting off, damaging the motor, why
is there no loss in performance, no more overheating and no signs there
was ever a problem??

I obviously can't trust this motor as I had, even though the thermal
protection does appear to be working properly. This thing would be a
real bitch to disassemble and rewind, though - assuming I can even get
my hands on the right gauges of magnet wire.

So, whaddya think? Should I continue to use this motor and just monitor
it carefully, or should I attempt a rewind just to be on the safe side?
Sure, I could buy another motor ($$$), but as I said, this one IS
working, so I'm not sure replacement is necessary at this point.

Anybody care to share their experience with these motors in terms of
expected lifespan after an overheating incident (or three)?

 

[hr(bob) [email protected]]

Got a GE 4.8A clothes dryer motor here which emitted some smoke one day
shortly after powering it up. I've been using this blower assembly for
solder fume extraction from my bench, so it had no drum loading the
motor down.
I shut it down before the thermal protection kicked in. I then blew all
the dust out that I could get to with an aerosol duster and hooked it up
to a switched, breaker outlet strip outdoors where there would be no
fire hazard (other than to the motor itself) so I could check it out
further.
Powered it up, it ran about 10 secs then smoked again. There was no
duct attached and the bearings turned freely (both before and after the
first smoking event), so it wasn't binding.
Tried it again, this time allowing it to run until the thermal
protection shut it off. After a couple more times powering it up and
letting the thermal protect do its thing, it worked perfectly from then
on - no smoke, no thermal runaway, no noticeable loss in CFM. It
continues to run flawlessly and does not overheat or smoke, even when I
block the inlet to purposely strain the motor.

Question is, what the heck was smoking? If it were dust burning off,
the motor would have had to have gotten hot enough TO burn it off, yet
the first time it only smoked a lot and didn't shut itself down. On the
other hand, if winding varnish were melting off, damaging the motor, why
is there no loss in performance, no more overheating and no signs there
was ever a problem??

I obviously can't trust this motor as I had, even though the thermal
protection does appear to be working properly. This thing would be a
real bitch to disassemble and rewind, though - assuming I can even get
my hands on the right gauges of magnet wire.

So, whaddya think? Should I continue to use this motor and just monitor
it carefully, or should I attempt a rewind just to be on the safe side?
Sure, I could buy another motor ($$$), but as I said, this one IS
working, so I'm not sure replacement is necessary at this point.

Anybody care to share their experience with these motors in terms of
expected lifespan after an overheating incident (or three)?

Is there a centrifical (sp?) switch that opens a starting winding that
maybe wasn't opening due to some dirt???

 

[Meat Plow]

Got a GE 4.8A clothes dryer motor here which emitted some smoke one day
shortly after powering it up. I've been using this blower assembly for
solder fume extraction from my bench, so it had no drum loading the
motor down.
I shut it down before the thermal protection kicked in. I then blew all
the dust out that I could get to with an aerosol duster and hooked it up
to a switched, breaker outlet strip outdoors where there would be no
fire hazard (other than to the motor itself) so I could check it out
further.
Powered it up, it ran about 10 secs then smoked again. There was no
duct attached and the bearings turned freely (both before and after the
first smoking event), so it wasn't binding.
Tried it again, this time allowing it to run until the thermal
protection shut it off. After a couple more times powering it up and
letting the thermal protect do its thing, it worked perfectly from then
on – no smoke, no thermal runaway, no noticeable loss in CFM. It
continues to run flawlessly and does not overheat or smoke, even when I
block the inlet to purposely strain the motor.

Question is, what the heck was smoking? If it were dust burning off,
the motor would have had to have gotten hot enough TO burn it off, yet
the first time it only smoked a lot and didn't shut itself down. On the
other hand, if winding varnish were melting off, damaging the motor, why
is there no loss in performance, no more overheating and no signs there
was ever a problem??

I obviously can't trust this motor as I had, even though the thermal
protection does appear to be working properly. This thing would be a
real bitch to disassemble and rewind, though – assuming I can even get
my hands on the right gauges of magnet wire.

So, whaddya think? Should I continue to use this motor and just monitor
it carefully, or should I attempt a rewind just to be on the safe side?
Sure, I could buy another motor ($$$), but as I said, this one IS
working, so I'm not sure replacement is necessary at this point.

Anybody care to share their experience with these motors in terms of
expected lifespan after an overheating incident (or three)?

Maybe some sort of start circuit failed to switch off causing the
smoke/problem but it's impossible to be certain without the model #
of the motor.

 

[James Sweet]

Maybe some sort of start circuit failed to switch off causing the
smoke/problem but it's impossible to be certain without the model #
of the motor.

Even if you had the model number for the motor, what good would it do? It
was probably made just for that series of dryer so that's probably all it
will get you, not technical details of what they consider a non serviceable
component.

 

[Meat Plow]

Even if you had the model number for the motor, what good would it do? It
was probably made just for that series of dryer so that's probably all it
will get you, not technical details of what they consider a non serviceable
component.

Well you never know what data is available if you don't look.

 

[Michael Kennedy]

Maybe some sort of start circuit failed to switch off causing the
smoke/problem but it's impossible to be certain without the model #
of the motor.

I've had that problem with these motors before. The start switch goes and
makes the thing overheat and smoke. The real problem was that mine was
rivited togeather, so I didn't even bother to try to fix it.

Mike

 

[Meat Plow]

I've had that problem with these motors before. The start switch goes and
makes the thing overheat and smoke. The real problem was that mine was
rivited togeather, so I didn't even bother to try to fix it.

Mike

It's probably not fixable but knowing for sure would fix my curiosity and
add to my knowledge base for future reference.

 

[Michael Kennedy]

It's probably not fixable but knowing for sure would fix my curiosity and
add to my knowledge base for future reference.

Well, it wasn't apparent at first but the switch is where the smoke came
from on mine and as I said I didn't bother to disassemble it because of the
rivits. Didn't seem worth the effort of grinding them out to get to a
centrifugal switch that I probably can't fix.

Mike

 

[Sam Goldwasser]

Even if you had the model number for the motor, what good would it do? It
was probably made just for that series of dryer so that's probably all it
will get you, not technical details of what they consider a non serviceable
component.

I'd go with a problem in the starting circuit. If the centrifugal
switch contacts stuck, the starting winding would overheat very quickly
as it's not designed for continuous operation.

However, I haven't actually looked at a dryer motor in 20 years or so.
I assume they are still induction motors!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[hr(bob) [email protected]]

I'd go with a problem in the starting circuit.  If the centrifugal
switch contacts stuck, the starting winding would overheat very quickly
as it's not designed for continuous operation.

However, I haven't actually looked at a dryer motor in 20 years or so.
I assume they are still induction motors!

--- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
 Repair | Main Table of Contents:http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ:http://www.repairfaq.org/sam/lasersam.htm
        | Mirror Sites:http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line.  Or, you can contact me via the Feedback Form in the FAQs.

Unfortunately I have, they still have a starting winding on the one I
worked on.

 

[Jamie]

Got a GE 4.8A clothes dryer motor here which emitted some smoke one day
shortly after powering it up. I've been using this blower assembly for
solder fume extraction from my bench, so it had no drum loading the
motor down.
I shut it down before the thermal protection kicked in. I then blew all
the dust out that I could get to with an aerosol duster and hooked it up
to a switched, breaker outlet strip outdoors where there would be no
fire hazard (other than to the motor itself) so I could check it out
further.
Powered it up, it ran about 10 secs then smoked again. There was no
duct attached and the bearings turned freely (both before and after the
first smoking event), so it wasn't binding.
Tried it again, this time allowing it to run until the thermal
protection shut it off. After a couple more times powering it up and
letting the thermal protect do its thing, it worked perfectly from then
on – no smoke, no thermal runaway, no noticeable loss in CFM. It
continues to run flawlessly and does not overheat or smoke, even when I
block the inlet to purposely strain the motor.

Question is, what the heck was smoking? If it were dust burning off,
the motor would have had to have gotten hot enough TO burn it off, yet
the first time it only smoked a lot and didn't shut itself down. On the
other hand, if winding varnish were melting off, damaging the motor, why
is there no loss in performance, no more overheating and no signs there
was ever a problem??

I obviously can't trust this motor as I had, even though the thermal
protection does appear to be working properly. This thing would be a
real bitch to disassemble and rewind, though – assuming I can even get
my hands on the right gauges of magnet wire.

So, whaddya think? Should I continue to use this motor and just monitor
it carefully, or should I attempt a rewind just to be on the safe side?
Sure, I could buy another motor ($$$), but as I said, this one IS
working, so I'm not sure replacement is necessary at this point.

Anybody care to share their experience with these motors in terms of
expected lifespan after an overheating incident (or three)?

You're to late, you let the smoke out!... there is no hope now!


--
"I'd rather have a bottle in front of me than a frontal lobotomy"

"Daily Thought:

SOME PEOPLE ARE LIKE SLINKIES. NOT REALLY GOOD FOR ANYTHING BUT
THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.
http://webpages.charter.net/jamie_5"

 

[Ray L. Volts]

Is there a centrifical (sp?) switch that opens a starting winding that
maybe wasn't opening due to some dirt???

It does use that type switch, yes. I checked the pins; contacts were
good; movement of switch lever was good. It could have been
sporadically sticking, I suppose; I guess I'll never know, but it
certainly isn't sticking now. I opened the switch assembly up and the
contacts are in good shape – I'll still burnish them to like-new
condition, though.

 

[Ray L. Volts]

Even if you had the model number for the motor, what good would it do? It
was probably made just for that series of dryer so that's probably all it
will get you, not technical details of what they consider a non serviceable
component.

Indeed, I found it impossible to squeeze any info out of GE at all on
this thing – it's got a great many sorts of identifying numbers on it,
none of which GE themselves could reference. I got the entire blower
for a song – and a little bit of time as a captive audience (the guy was
bored and lonely – from an appliance repair shop. The shop owner
couldn't tell me which dryer it came out of, so I can't go on that kind
of info, either.

 

[Ray L. Volts]

Well, it wasn't apparent at first but the switch is where the smoke came
from on mine and as I said I didn't bother to disassemble it because of the
rivits. Didn't seem worth the effort of grinding them out to get to a
centrifugal switch that I probably can't fix.

Mike

I opened this one up. In my case, no drilling or grinding was required.
It was a simple matter of prying up the rivet rims with a jeweler's
flat blade driver and pushing them through with an appropriate size hex
driver.
The switch contacts are in decent shape and the switch levers move
freely (and appear to have done so all along, as it's clean around the
pivot points). There's also a fairly powerful spring pushing down on
the starter switch lever, ensuring disconnect – from the compression
force required (calibrated finger, admittedly), this spring seems quite
adequate to break a sticking contact. I honestly can't see this switch
as the culprit, but it's possible.