Shop/Barrel/Drum Fan Electric Motor

I've always wanted a big fan for my shop, as it gets miserably hot June-October; but wasn't willing to pay $400+ for one (I've survived with several smaller fans running). Recently, I found a 42" "Country Tuff" (Orscheln's Farm & Home chinese brand, single phase, 1/2hp, 2 speed) fan in nearly new condition, priced right, but it has an issue: Whether low or high is selected, the motor will starts great, but will cut out/quit at 1-3 minutes and stop. Having fried motors before, I always shut the power off when it does this, so I'm not sure how it would react if power was left on to the motor. You can feel very slight warmth in the motor housing, but it's only ever ran 1-3 minutes, so it's not hot. It has a 25uF CBB61 "Run" capacitor that I immediately suspected & replaced; without a change in results. My next thought was that there may be a thermal switch/issue located in the motor, so I've now removed the motor and have taken it apart. Unless there's a switch located in this zip-tied wrapped mess (which is on the interior of the housing tied around the windings).....I'm not seeing one. In hindsight, I should have wired it up direct and tested before removing/disassembling.

I have other motors that I could retro for this application; but nothing short/compact enough to be an easy fit & remain inside of the enclosure/guards. I'll include pics in a following post.

Any advice/thoughts/words of wisdom?

Thanks-

If you leave it alone for a while, presumably it starts?

Yes, likely the thermal cutout. It has one, probably a flat thing about 10 x 20 x 5mm that is stuffed in among the end turns pf the windings.

Case may not be hot, but windings may be. Or the cutout may be bad, the wrong type, etc. Or, since 1 to 3 minutes is not very long, it may have a problem, and the cutout is doing it's job.

I'd not expect to feel any real heat in the case if the motor ran that long. Depends on what you call "warm", vs what I would.... "what we think" is not a "measurement".

BTW, that s a "run" capacitor, and that motor looks small. I do not see any darkened windings, so probably not actually overheating, especially if you do not smell any "hot varnish" smell.

Motor RPM? Not shown on tag, but if that is direct drive, it will be pretty low.

Are the pulleys (if any) original as far as you can see?

I appreciate the reply-

JST said:

If you leave it alone for a while, presumably it starts?

Click to expand...

-Yes; if allowed to sit for just a couple of minutes, it will restart fine......run a couple of minutes and quit again.

JST said:

Yes, likely the thermal cutout. It has one, probably a flat thing about 10 x 20 x 5mm that is stuffed in among the end turns pf the windings.

Click to expand...

-Nothing like that is apparent on either side of the motor windings; do you think agree that it's within the wrapped/zip-tied portion? Should I start snipping zip ties....? Was just a little concerned about being able to get it back together....correctly.

JST said:

I'd not expect to feel any real heat in the case if the motor ran that long. Depends on what you call "warm", vs what I would.... "what we think" is not a "measurement".
BTW, that s a "run" capacitor, and that motor looks small. I do not see any darkened windings, so probably not actually overheating, especially if you do not smell any "hot varnish" smell.

Click to expand...

-Yeah, I realize that "warm" was subjective.....it was an 85° day, and I could only *barely* feel any heat on the housing. No "burnt" smells at all (& I gave it the sniff test).

JST said:

Motor RPM? Not shown on tag, but if that is direct drive, it will be pretty low.

Are the pulleys (if any) original as far as you can see?

Click to expand...

-It isn't a direct drive, a v-belt connects the motor & the fan shaft. The pulleys are original; they've never been off, and it obviously hasn't ran much since new. The RPM isn't listed on the tag.....but the fan is nearly identical (except for the Hi/Low/Off switch) to these models offered at other outlets:

KOOL-FLO 48.9 in. H X 42 in. D 2 speed Drum Fan - Ace Hardware

Error | DNS Resolution | Northern Tool + Equipment

Before removing/disassembling the motor, I removed the belt to see if there was any change to the motor's operation without a load. Same story; it quit after a couple of minutes.

The cutouts can develop a bad connection, or even be damaged when installed. After that, the high resistance of a bad connection will often cause them to open after some undetermined time. Combination of normal heat plus extra heating due to bad connection.

Still could be an actual problem, although the odds in favor are going down a bit.

The cutout probably will not be down in a slot, no room, and the cutout might not work too well. More usually in the end turns, which heat up faster because they do not have iron around them to soak up heat.

Some of them are made to sense current, and those might be anywhere. Those can also go bad, or be poorly located where they get extra heat.

It's in there, somewhere.

Do you have a clamp-meter? Check if it's still drawing current when it's stopped. I expect it's not, and that would point towards a bad connection or cutout.

JST said:

It's in there, somewhere.

Click to expand...

I just wanted to circle back, say "thanks" for the replies, & report the solution (so that it may help someone down the road). After working up the nerve to gently cut the lacquered yarn & zip ties off of the windings where the connections are.....I was able to sort out the high & low speed windings, along with the neutral, which connected with one of the black wires shown in the picture below, that ran to the thermal switch that was deeply nestled in the ends of the windings. While it likely isn't "OSHA Approved", I cut & connected the black wires, to bypass the switch. Zip tied everything back together and voila!! Works like a champ-

Thanks again!