Interesting AC monorized impeller

[bobkoure]

I ran across this

at American Science and Surplus for $9.95.
Although they only hint at it, I'm pretty sure it's a Papst R23133.
I've ordered a couple to play with and will follow up - but I'm focused on quiet, so I'll use a fan controller to slow it down.

I thought someone else here might find these of interest, so I'm mentioning 'em now (AmSci/Surp runs out of stuff all the time).
If I wasn't a low-noise guy and wanted an external rad box, I'd think about building a box the same width and depth of my PC, but only four inches tall or so. One or two of these impellers in the top, one or two sides with one of those 14"x3.5" single pass heater cores on the long side(s) and I'd be in business.
Just a thought, of course...

[jlrii]

I have 2 of them. They are an EBM, full model # is R2S133-AB25-22. Rating is 115v 60hz 40w or 115v 50hz 45w. Unfortunatly the motor is a shaded pole which doesn't respond as well as a PSC motor to speed control and is not as efficient.The motor is totaly enclosed non-ventilated, insulation class "b" which is 130 deg C...read they run very hot. They do however move a LOT of air. Waiting for a new speed control for mine with a minimum setting. I was hoping they were the PSC variant still deciding whether or not to use them.

EDIT: this is what concerns me abbout reducing the speed

"Suitable motors with matching fan loads can provide a range of speed variation from maximum speed to say 30% of maximum speed. For standard motors, the minimum speed should not be lower that say 80% of maximum speed (air flow rate reduced by approximately 35%). In any event, for standard motors, it is wise to ensure temperature limits are not exceeded at reduced speeds."

Since slowing a shaded pole motor is acomplished by increasing slip, and considering that they already run hot (too hot to hold in your hand). I think speed control may burn these up. Heat sinks for motors anyone?

[satanicoo]

Water-cool them.

[jlrii]

Hmm...just found this on EBM's site tho:

"SPEED CONTROL
All ebm external rotor motors are 100% speed controllable
by voltage reduction or other means and operate at very low
voltages without overheating or reducing reliability. The outstanding
advantage of ebm/Papst motors, when speed controlled,
is their STABILITY which permits proper balance between
air flow and noise."

gonna have to break out the digital thermometer.

[redleader]

Anyone have a photo of one? Looks interesting.

[bobkoure]

Originally Posted by jlrii

I have 2 of them. They are an EBM, full model # is R2S133-AB25-22.

I've tried searching ebmpapst for this model but can't find it. Any chances of posting a link?
If I manage to get one of these throttled back to near-silence and it still pulls a decent CFM through a 2" core, but the motor gets too hot, I'd consider buying the 24V version, even though I'd have to pay lots to get it through Newark (or someplace like that).
Having looked at the flow diagrams that JapanServo publishes (see some of my earlier posts) it looks as though they are focused on making a forward-bladed fan quieter - and a reverse bladed fan shouldn't have the same turbulence (look at the leading edge of the JS fan - it's nearly a reverse blade). Given this, I don't understand why reverse bladed fans should be louder than forward bladed ones. Maybe the snail housing cuts some noise?

Originally Posted by redleader

Anyone have a photo of one?

AS&S isn't really fast at shipping (and I ordered the cheapest "by donkey cart" shipping ) but I'll follow up with photos when I get one in-hand.

[jlrii]

Check your link, first post, top unit in chart. Sorry I listed their part # not model #.

[bobkoure]

As promised, pictures of one of the units I got in (click thumbnail for a bigger picture)




The speed controller from Edmunds seems to work OK. I've tried running this one with the motor speed-controlled down to under 30dB somewhere and, after a half-hour it's not too hot to touch. Turned all the way up, it pulls lots of air and with good suction.
This one is dated 1990 and is a take-out. You can get a new one at Newark
I'd been thinking of getting an equivalent DC model so maybe a R1G133 but they're something like $US185 .
Either way, as a low-noise guy, this represents a failed experiment - they don't appear to move much air when speed-controlled down under 20dB - time for me to chase thin (low resistance) radiators
FWIW, these motorized impellers are much better quality than the comair/rotron ones I found earlier at allelectronics. The impeller is well centered and balanced - just plug it in and go. If I didn't mind some noise, I'd be very happy using one of these to pull air through a radiator...

[BillA]

failed noise perhaps, but rather informative nonetheless

[bigben2k]

Excellent info, thanks!

Which part got hot, the controller or the fan motor?

edit: a bigger diameter should get you to your target.

[bobkoure]

Originally Posted by bigben2k

Which part got hot, the controller or the fan motor?

The fan motor (more specifically the back side that stays stationary) is the part that gets hot. If I was going to mount this fan on a plate, I'd use thermal compound and screws in all six mounting holes so as to use the plate as a heatsink.
I think you're right about lower noise from larger diameter, although if it's a matter of noise going up with fan blade airspeed, then I dunno...