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Re: Fan wiring
I am assuming that the fan you are using runs straight 120 volt AC and
probably plugs into the wall.
If so, return the potentiometer, go to the hardware store or WalMart and buy
yourself a light dimmer (just like you would use to replace a wall switch),
a plastic receptacle box that it will fit in, three wire nuts for 12 to 16
gauge wire, a short outdoor type extension cord, and a light switch cover
plate if the dimmer switch doesn't come with one.
Pick a spot in the middle of the extension cord and cut it in half, making a
plug end and a receptacle end. Strip the outside insulation back about two
inches from the cut on both pieces. The inner wires exposed should be
white, black and green or bare. Strip the insulation back on these wires
about one inch. The receptacle box should have punch outs in each end.
Thread the cut ends of the extension cord into the box from opposite ends,
so that you have an extension cord with a box, with a lot of wires coming
out of it, in the middle.
The dimmer switch will likely have color coded wires and installation
instructions. If it's just got two wires, wire it into the black line and
reconnect the white and green. To wire it, hold the bare ends of the wire
together side by side, twist them together clockwise and then screw the wire
nut on clockwise. If the inside wires are not color coded, the wire that
attaches to the plug blade on the left as you look straight at it, the
smaller blade if there is no ground, equates to black, or hot.
Stuff everything tight into the box, screw the dimmer in and put the cover
plate on. You now have a dimmer cord, or reostat cord and you can plug into
To answer your question about ruining the motor. If you run an electric
motor too slowly with too much load on it, it will over heat. I don't think
you will have that problem, but you might put your hand on the motor now and
see how hot it runs, if it's noticeably hotter after you slow it down, it's
A couple of words of caution: The rig I describe here is susceptable to
being pulled apart so you might tie a knot in the cord to keep it from
pulling thru the punch outs in the box and stressing your connections, or
tie the cord in a square knot on the back of the box after it's finished.
The rig is also susceptable to getting wet. Keep the box in a dry location.
Metal receptacle boxes are made with connections that will clamp down on a
cord. Tradesmen use these boxes to build a variety of interesting extension
Another possible source of a reostat is a kitchen range hood. Most of them
have infinitely variable fan speed, via a reostat.
Having said all this, I'm still not sure you are going to get the results
you seek. Fan noise can come from a poorly balanced fan, poorly balanced
motor, or poor mounting. If possible you might try running the fans in an
attitude 90 degrees from what it is running now, mounting it with soft
rubber washers to isolate it, or mounting it solid if it is currently soft
mounted. If the fan is a propeller type and it will easily come off it's
shaft, you might set it on top of a dishwashing liquid bottle on a flat
level surface. Balance it there and let it go. Turn it 90 degrees and let
it go again. If the same blade tips down smartly each time, the fan is out
of balance. Shave a little material off the end of the heavy blade until it
balances. You won't likely get a perfect balance this way, but at least a