welding vent fan - shaded pole - how to trouble shoot

I picked up a used $10 Nutone 300 cfm vent fan that I want to use over
my welding table. THe problem is that the fan motor runs - slowly (it
is rated at 1600 RPM). THe exact replacement motor is the same cost
as buying a new fan asm (about $155+). THis is a 3.3 inch (dia),
single speed, double shafted shaded pole motor. If I open up the
motor can, is there any hope of a minor repair? I have already lubed
the sleeve brgs - no change in RPM. Running it for 30 sec to a
minute, the motor sounds OK and the motor does not heat up, nor does
it smell burnt.
The Nutone motor number is 58840. It looks like Grainger has a
similar motor (hex mounting feature on the ends, but w/ 0.25 shaft dia
instead of 5/16). I could always turn some sleeves. I have also
found a Fasco D367 where I would need to modify the mounting of the
motor to the blower housing and cut down the shaft length but the
shaft dia is correct at 5/16. I still need to stop at either the
orange or blue big box and see what other vent fan options/prices are
available.
Reply to
aribert neumann
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Is the motor possible made for 240 volts and you are running at 120 volts?
Paul
Reply to
Paul Drahn
How many RPM does it run? Some are rated at 1300 RPM.
The JA2M291N motor is cheaper at $105 but at 1300 RPM would convert your unit to 200 CFM operation.
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Might this be sufficient?
--Winston
Reply to
Winston
Try Herbach and Rademan on the web. They have a bunch of blowers at fairly reasonable prices.
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Dan
Reply to
dcaster
Did it vent frying fumes? Cooking oil slowly polymerizes into Linoleum. You might be able to salvage it by washing out the bearings with solvent or it may need to be disassembled and scrubbed.
jsw
Reply to
Jim Wilkins
"Jim Wilkins" fired this volley in news:jhavvv$dg$ snipped-for-privacy@dont-email.me:
I'll second that. (well, Varnish, not Linoleum, which has paper fibers in it, too )
There's just not much that can go wrong with those shaded-pole motors. Most are even "impedance protected", so they won't burn out even if stalled.
For grins, try "lubricating" the bearings with an excess of a solvent- based break-free like P-Blaster or Kroil. Try not to get it on the coil, but let the excess run out of the bearings into a rag. After it soaks a while, try the fan again, and when it finally runs free, lubricate it with a light machine oil.
Hint. When you spin the fan by hand, it should turn so freely that it will coast 15-20 turns on its own after you give it a flick. If it doesn't, the bearings are gummed up.
I've repaired many the muffin fan with a few drops of xylene in the bearings, followed by oil.
Lloyd
Reply to
Lloyd E. Sponenburgh
"Lloyd E. Sponenburgh" fired this volley in news:Xns9FF85698B5525lloydspmindspringcom@216.168.3.70:
Oh... if the fan is plastic, keep it off that, too. Many of the plastic fans are made of polystyrene, and P-Blaster will dissolve styrene. (fast!)
LLoyd
Reply to
Lloyd E. Sponenburgh
When you need solvent, always reach for the WD-40...
Reply to
Dave__67
When I need solvent, I reach for acetone, MEK, xylol, lac thinner, methylene chloride, naptha, paint thinner, ethanol, methanol, or a couple of others not on the tip of my tongue. Certainly never reach for WD-40 when I need a SOLVENT. Nor when I need a penetrating oil. Only when I need a water-displacer (hardly ever).
YMMV, but if it does, I would recommend reconsidering.
Bob
Reply to
Bob Engelhardt
Thanks All.
The motor is labeled 120v, 1600 rpm. I also thought the sleeve bearings were dry / gummed up and I tried to lube them w/ some Tri- Flow and also some air tool oil (its what I had on hand in my basement where I dismantled the motor from the squirrel cage housing). When I spin the shaft by hand, there is no obvious stiction but the effort seemed to high and it stops rotating within 1/3 to 1/2 turn after I release it. I did not think of using a solvent to try to wash the bearing interface out. Do you all think that merely dripping solvent into the oil lube access will eventually dissolve the varnish? Or should I remove one of the motor end plates - this motor does not use tie bolts - local slots in the motor can are staked to the end-plates - just a bit more work to dismantle and reassemble.
Reply to
aribert neumann
Try a bit of Easy-Off to dissolve the gunk, and like the others have said, avoid the wires.
Reply to
Denis G.
That depends on what it is, I can't tell from here. Try all the non- destructive methods first, including running it for a while with light oil in the bearings to break up the softened crud. I've salvaged some slow or stuck motors with just solvent and oil, others needed to be disassembled and even drilled to add oiling holes,like the heater fan on my truck.
This and Norvey 'Turbine Oil' have worked well enough for me:
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Neither lasts forever.
jsw
Reply to
Jim Wilkins
What comes to mind to me, is to flush out the motor with brake cleaner. I've also used ether starting spray. Usual flammable cautions apply. Relube the bearings with zoom spout turbine oil (ND-20 or ND-30 or two cycle mix oil are acceptable). I've been known to also put a bit of graphite into the oil. See if that helps.
A friend of mine has Nutone bathroom vent fan, that has taken a couple dissembly and relube to get it right.
Please let us know how things work out.
Christopher A. Young Learn more about Jesus
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.
Thanks All.
The motor is labeled 120v, 1600 rpm. I also thought the sleeve bearings were dry / gummed up and I tried to lube them w/ some Tri- Flow and also some air tool oil (its what I had on hand in my basement where I dismantled the motor from the squirrel cage housing). When I spin the shaft by hand, there is no obvious stiction but the effort seemed to high and it stops rotating within 1/3 to 1/2 turn after I release it. I did not think of using a solvent to try to wash the bearing interface out. Do you all think that merely dripping solvent into the oil lube access will eventually dissolve the varnish? Or should I remove one of the motor end plates - this motor does not use tie bolts - local slots in the motor can are staked to the end-plates - just a bit more work to dismantle and reassemble.
Reply to
Stormin Mormon
Just bite the bullet and disassemble it. The bushings have felt surrounding them which hold oil. If you don't disassemble you can't flood this felt with oil and your half assed repair job won't last very long. BTDT. Take the time and do it right. My bathroom fans now last 3+ years between oilings. Mark everything prior to disassembly so you can get it back together correctly or it just may run backwards. BTDT too. Art
Reply to
Artemus
The holes I mentioned drilling in my truck's heater fan give access to this felt to add more oil with a sewing machine needle oiler.
jsw
Reply to
Jim Wilkins
I used lacquer thinner as my solvent. At first I tried dripping a few drops down the motor shaft, spinning the shaft by hand, repeat for about a dozen times, flip over and do the other side. Still felt like the armature was spinning in STP or honey. I started dripping the lacquer thinner down the oiling holes and after a while I could spin by hand, release and get **a full rotation** before the armature stopped spinning. Then I plugged it in and while running started spraying in 3-in1 aerosol (originally posted it as Tri-Flow). Put an optical tach on it and read 1700+ rpm (motor label says 1600 rpm). I let it run w/o either of the squirrel cages attached while adding a drop or two of air tool oil every few minutes until the motor can got too hot to hold for more than seconds at a time. SHut it off, added more oil during cool down and then ran it some more - all the while adding a drop of oil every now and then. I have not seen any excess oil dripping out - I'll leave it on the bench for a few days and maybe add a few more drops before reassembling the motor into the housing.
Again - thanks for the replys. I am so looking forward to being able to draw welding fumes out near the source rather than using the furnace blower that I have set up to draw from a hole in the ceiling (18 feet away from the welding table) and to vent out of the garage gable. Using the big furnace blower can be a serious waste of heat in the winter time.
Reply to
aribert neumann
SHut it off, added
Most of these motors with sintered bronze bearings have a felt oil reservoir around the bearing. They can actually take a LOT of oil, but it takes a while to soak in. I'd add a lot more than a few drops, maybe a couple CCs per bearing. You may be able to see enough of the felt to tell when it is getting saturated.
Jon
Reply to
Jon Elson
And a piece of duct tape covers the hole until it's needed the next time.
-- Fear not those who argue but those who dodge. -- Marie Ebner von Eschenbach
Reply to
Larry Jaques
Duct tape didn't survive the engine compartment heat. Aluminum autobody repair tape has been OK so far.
jsw
Reply to
Jim Wilkins
Oh, I thought it was an underdash thang. Aluminum duct tape works under the hood, too. That stuff'll take a finger off if you're not careful with it.
-- Fear not those who argue but those who dodge. -- Marie Ebner von Eschenbach
Reply to
Larry Jaques

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