"Continuous Air Over Duty" motors - AKA "Totally Enclosed Air-Over"

[John Mowgli]

I have a line on some 1 HP 1725 RPM motors for a great price.
The only catch is that they're "Continuous Air Over Duty" as opposed to TEFC.
They're intended purpose is continous duty fans, hence the air over cooling.

I think they should be fine for the 1/2 hour at a time or so that my lathe might be on for.
I think it's worth a try at $50 for a new 1 HP motor.

Anyone have any experience with using Continuous Air Over Duty motors on lathes?

Thanks

[Richard Madison]

Sounds like a different name for the same thing. What is different about the motor from a TEFC motor?

[John Mowgli]

Sounds like a different name for the same thing. What is different about the motor from a TEFC motor?

TEFC is fan cooled (internally)
TEAO are cooled by air running over the outside of the motor, such as in powering a continous duty fan
The body of the motor must act as a heat-sink

[Richard Madison]

Not cooled internally John.

A TEFC enclosure on a motor means "Totally Enclosed, Fan Cooled". This is probably the most commonly used motor in ordinary industrial environments. It costs only a few dollars more than the open motor, yet offers good protection against common hazards. It is constructed with a small fan on the rear shaft of the motor, usually covered by a housing. This fan draws air over the motor fins, removing excess heat and cooling the motor. The enclosure is "Totally Enclosed". This ordinarily means that the motor is dust tight, and has a moderate water seal as well. Note that TEFC motors are not secure against high pressure water.

[Denis Puland]

If it is designed to drive a fan with the air moving over it then forget about it!!!!
Get the proper motor and save yourself some headache and money in the long run.

Denis

[Dennis Ford]

As had been said, the TEFC motors have a fan attached at one end. The "air over" motor is designed to drive a fan so it does not have a fan included with the motor. TEFC motors are easily found for reasonable prices, I would not bother with an "air over" rated motor.

It may work on a lathe for you or you may burn it up. This will depend on how you use it. If it fails, you have learned something. If it works, you have saved a few dollars.

[Richard Madison]

Ok, now it makes sense. The TEAO is intended to be located in the airflow of the fan it drives. With no airflow over the motor, it will overheat, as would a TEFC motor if you removed the shroud and fan and ran it that way.

[Allen Neighbors]

I have a TEAO motor, Richard. I also have fans in my shop, and used one of them to blow on the motor when I used it on an old craftsman lathe. A 1HP motor is worth the $50 bucks, for sure, if they are any good to begin with.
I have small motor that is gear operated... it is not totally enclosed, but it ran hot when I mounted it on my HF tumbler. To solve the problem, I taped a small pancake fan to the back of the motor, and it solved the overheating problem. I can now turn the motor on and tumble a HF with rocks inside for 8 hours at a time without it overheating. There may be a similar way you could cool the TEAO 1HP motor. The choice is yours, of course. Only you can determine if it would be worth it.
If you have the fans on hand, and don't have to purchase them, in addition to the motor, it might be.

[Richard Madison]

John,
So back to your original post, the TEAO motor might indeed work well for the short (you said 1/2 hour) stints you mentioned if allowed to cool between uses. And you might not be running it fully loaded which would help. Could always add a small auxilliary fan as Allen suggested. How to tell if it is too hot without instruments? If you can hold your hand on it (about 125F or less) it's ok. If you can hold your hand on it briefly (130-135F) it's probably still ok. Beyond that it is too hot.

[John Mowgli]

John,
So back to your original post, the TEAO motor might indeed work well for the short (you said 1/2 hour) stints you mentioned if allowed to cool between uses. And you might not be running it fully loaded which would help. Could always add a small auxilliary fan as Allen suggested. How to tell if it is too hot without instruments? If you can hold your hand on it (about 125F or less) it's ok. If you can hold your hand on it briefly (130-135F) it's probably still ok. Beyond that it is too hot.

That sounds like my kind of formal precision test.
If it burns my hand it's too hot.

He has 22 of these left.
He said he sells 2-3/week.
I'll see if I have any extra $50's in a few weeks and probably get one.
I know it's good bang for the buck if it lasts.

I could use the office fan I use to circulate the hot air from my woodstove if I need to but I'll see in a few weeks if it'll even be worth getting.
I just turned a a long rectangle into a dowel to test my tool sharpening skills (EPIC fail!) and It seems my current setup should be sufficient for a while.

I'll post back here with results if I do get one.
Thanks for the input