How can I reverse this fan?

Salty

Salty

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Salty
Is there a way to set up this type of fan to reverse it's rotation without disassembling every time. Disassembly to modify it is fine, but I want to be able to flip a switch or something and have it rotate the other way.

Alternatively, a different fan that is belt drive (quiet) no more than 36" (30 is ideal) that can be reversed would be even better. It does not have to be mobile because I will be mounting it permanently anyway, but so far, these are the cheapest I can find. But I've not found any that reverse yet at any cost.

1220312
 
It depends on the motor, but it's not likely reversible. But it could be, so it's worth investigating. Beyond that, the large fans we had in our building only blew outward; there were days we wished otherwise.
 
Change over to a 3P motor and add a VFD and you get reversing and variable speed with a couple of button pushes.
 
Don't some whole house fans have the ability to reverse?
 
eman1200 said:
turn it around?
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Turning it around won't reverse the rotating direction. I worded my question carefully to avoid this kind of smart aleck response.
 
I did that a few times when I was a kid, just because I liked to take things apart and burn out fuses. All I did was reverse the polarity of one of the windings (but not both).

Of course, I was probably about 10 the last time I did it, so my memory could be off.

Rich
 
Craig said:
Change over to a 3P motor and add a VFD and you get reversing and variable speed with a couple of button pushes.
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Can you say that in English?
 
Salty said:
Turning it around won't reverse the rotating direction. I worded my question carefully to avoid this kind of smart aleck response.
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Turning it around was my thought also.... A pusher airplane engine don't turn opposite than a puller... My Breezy had a 172 engine :)
 
Mtns2Skies said:
Use a 3phase motor, aka 240Volt or 480Volt motor and a variable frequency drive. This will work, he's right.
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Okay, we're making progress. I understood all those words. ;) How do I find a 3 phase motor? 240V AC? And what is, and how do I source a "variable frequency drive"?

PS> This sounds like it's going to cost me a fortune.
 
pigpenracing said:
Turning it around was my thought also.... A pusher airplane engine don't turn opposite than a puller... My Breezy had a 172 engine :)
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But my requirement IS to be able reverse the rotation. A pusher airplane is irrelevant.
 
still curious how reversing the rotation would be useful but turning it around would not serve the same purpose! Must be awkward or too tight a space to flip it? (after all, it is wheeled already)
 
Twist the drive belt?

Replace the belt and pulleys with drive gears?
 
If a fan normally blows air from left to right, reversing it would blow right to left, just like turning it around. Why can't it be turned around?

If turning it around won't work then flip it 180 about the horizontal axis. (But not the axis of rotation)
 
Maybe he wants it permanently installed on the side of a shed or something
 
Salty said:
Okay, we're making progress. I understood all those words. ;) How do I find a 3 phase motor? 240V AC? And what is, and how do I source a "variable frequency drive"?

PS> This sounds like it's going to cost me a fortune.
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Do you have 3 phase power?
 
Mtns2Skies said:
Use a 3phase motor, aka 240Volt or 480Volt motor and a variable frequency drive. This will work, he's right.
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Just because it’s 240V doesn’t mean it’s three phase. And the odds of having three phase power at a home or even business in non industrial areas is poor.

If you did, reversing any two of the three hot wires would reverse the rotation (Don’t do it while the motor is running!).

Single phase 110 or 220 requires access to the motors internal wiring which may or may not be possible. And still never do it with the motor running!
 
Salty said:
It does not have to be mobile because I will be mounting it permanently anyway, but so far, these are the cheapest I can find. But I've not found any that reverse yet at any cost.
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I finally re-read your post. You put a portable fan in your picture, but you want a perma reversing fan.

How about this: Construct an enclosure to mount it in, and flip it to the flow direction you want?

I presume the different flow direction doesn't change all that often.
 
Salty said:
Okay, we're making progress. I understood all those words. ;) How do I find a 3 phase motor? 240V AC? And what is, and how do I source a "variable frequency drive"?

PS> This sounds like it's going to cost me a fortune.
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Rather more than the cost of the fan, yes.

If you reverse the motor it'll be less efficient because of the curvature of the blades. It'll still blow, but a lot slower, just like mounting a propeller backwards on an airplane. With a fan like that, why don't you just turn it around? Why do you need to reverse it?
 
Replace the belt with an oversized one. Put a double wheel arrangement on a lever. Lever in reverse position, the clockwise drive pulley turns transmission wheel #1 counterclockwise, transmission wheel #1 turns wheel #2 clockwise, transmission wheel #2 turns fan pulley counterclockwise. Lever in forward position, the transmission wheels disengage, an idler pulley engages and clockwise drive pulley turns fan pulley clockwise.
 
asicer said:
Replace the belt with an oversized one. Put a double wheel arrangement on a lever. Lever in reverse position, the clockwise drive pulley turns transmission wheel #1 counterclockwise, transmission wheel #1 turns wheel #2 clockwise, transmission wheel #2 turns fan pulley counterclockwise. Lever in forward position, the transmission wheels disengage, an idler pulley engages and clockwise drive pulley turns fan pulley clockwise.
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That sounds like a $15.00 project... He wants this done free :)
 
Ravioli said:
I finally re-read your post. You put a portable fan in your picture, but you want a perma reversing fan.

How about this: Construct an enclosure to mount it in, and flip it to the flow direction you want?

I presume the different flow direction doesn't change all that often.
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Salty said:
Maybe he said that in the original post
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Oh I read that. But permanently mounting does not mean that the enclosure that it's mounted in isn't variable. 2 bolts and a pin and it's done. Cost at Lowes: less than 5 bucks.
 
EdFred said:
Oh I read that. But permanently mounting does not mean that the enclosure that it's mounted in isn't variable. 2 bolts and a pin and it's done. Cost at Lowes: less than 5 bucks.
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Would require too much space and be too unwieldy in the location to be installed.
 
pigpenracing said:
That sounds like a $15.00 project... He wants this done free :)
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I never said free. The 3phase motor solution was looking like it would approach or exceed $1000 with the fan and other parts.
 
Mount a second motor to the other side.
Forward use front motor
Backwards use back motor
 
asicer said:
Replace the belt with an oversized one. Put a double wheel arrangement on a lever. Lever in reverse position, the clockwise drive pulley turns transmission wheel #1 counterclockwise, transmission wheel #1 turns wheel #2 clockwise, transmission wheel #2 turns fan pulley counterclockwise. Lever in forward position, the transmission wheels disengage, an idler pulley engages and clockwise drive pulley turns fan pulley clockwise.
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This seems like it might work, but I’m not Sure how to implement it
 
Back on that three phase motor thing (and assuming you have three phase available), it makes no sense to install a VFD. All you need is a switch to reverse two of the power leads and bam, there is your reverse.

Otherwise see post #7, follow the link and it will give you detailed instructions for both capacitor start and dual winding single phase motors.
 
pigpenracing said:
Mount a second motor to the other side.
Forward use front motor
Backwards use back motor
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Not sure exactly how other than maybe having a shared shaft. I wonder how much drag the unused motor would create when the other is turning it. I also wonder if it would do damage to the circuitry acting as a generator.
 
Sac Arrow said:
Back on that three phase motor thing (and assuming you have three phase available), it makes no sense to install a VFD. All you need is a switch to reverse two of the power leads and bam, there is your reverse.

Otherwise see post #7, follow the link and it will give you detailed instructions for both capacitor start and dual winding single phase motors.
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Don’t have 3 phase. Will look at that link, I haven’t yet.
 
There's a video on how to reverse a single phase motor. Looks like it could be done with some strands of 14 gauge copper and a switch.
 
Salty said:
Not sure exactly how other than maybe having a shared shaft. I wonder how much drag the unused motor would create when the other is turning it. I also wonder if it would do damage to the circuitry acting as a generator.
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AC motor, no permanent magnet, it will neither generate electricity nor impose much in the way of drag. Ever notice what a window fan does in the breeze? It freewheels.
 
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