Hello!
I found an old McLean Engineering cooling fan. I removed the squirrel cage fan assy from the chassis.
The motor is marked "115v, 2A, 3100rpm, Capacitor 4mfd @ 400V, Class F, thermal protection", etc.
A wiring sticker on the chassis: "Air Flow Switch: White=common, Black=N.O., Green=N.C."
It moves a LOT of air, like a leaf blower. It's smooth but the fans are a bit loud. It's a hog: startup peak is 2.4A, 250w for almost 2 seconds. Running = 1.15A, 140w.
The fan assy is small enough to fit in a short wood-joist "ductway" in my house that allows heat from the woodstove to distribute into an adjacent room.
My project is to modify the fan assy so that it runs much slower (quieter and uses less power), and then install it into the ductway to pull heated air into the other room. Conveniently, I have romex passing thru the ductway, so I can install a junction and receptacle and maybe even a switch.
**broken link removed**
**broken link removed**
Questions:
1 - what is the purpose of the Nytronics 4mfd 40vDC capacitor on the N.O leg? The cap was mounted to the exterior steel surface of the chassis. Is this an oil cap, or dry? Is it a filter of some kind, or related to startup draw, or what? (these questions are just for my education, thanks
)
The existing motor is strong and smooth and quiet by itself; no slop in the bearings/bushings; turns real easy.
2 - What's the best approach? Is there a reasonably efficient way to slow down the existing motor? Or do I need to replace the motor with a smaller one?
The fans come off easily. They are on 1/4" shafts on either end of the motor, held in place with set screws.
3 - Is there a chart somewhere that lists rpm/fan diameter/cfm lookups?
Possibly, I could get a motor with one output shaft and use only one fan instead of two.
4 - What about DC motor running off a wall wart or other transformer?
5 - lastly - where does one buy small and medium size electric motors? Are surplus motors okay, or is it better to buy new? Links to favorite suppliers?
Priorities: reasonable budget, efficient.
THANKS!