Wiring a Box Fan

Factual Questions
1

I know this is a weird request.

I have a 3-speed box fan (low, med, high)
& I want to Wire it to we’re the fan will run on
Low speed no matter if I have the
Switch selected on low, med, or high.

I want to use the fan existing speed switch.

Can you explain how to wire this or
A simple wire diagram?

Thanks

2

Would like to see a wiring diagram to give a definitive answer. But I would think it can be done by simply cutting the medium speed and high speed wires that are going to their respective output terminals on the switch, and then connecting the low speed wire to each of the three output terminals on the switch (low, medium, and high).

3

I agree with Crafter. Without seeing the actual wiring, I would assume the actual speed is handled by the motor and not the switch. If this is the case, you should see 4 wires going to the switch. One in and 3 out.
All you would need to do is cut the 3 coming out and connect all three of the cut wires on the switch side to high setting on the fan side. Make sure to mark which is which before you cut them. Maybe a colored mark or different color piece of tape on each one at each end.
Figuring out which is witch, assuming no labels isn’t difficult with a multimeter or voltage detector.

I did something somewhat similar when I put an LED bulb in my stove hood. It had a high and low setting and rewired it so both selections are ‘high’.

ETA: I just glanced at my cheap box fan and that’s exactly the setup it has. 4 wires into the switch. So that’s 120v in and the switch sends power out through 1 of 4 wires. It then likely has a multi speed motor. It’s going to be up to you to figure out which wire is which. It’s not difficult with a meter, but if you do it wrong you’ll probably end up with A)nothing happening B)a short C)the fan is always on or D)the motor destroying itself in one way or another.

4

Two more things, I meant “low” in my post not “high”

Depending on the application, another option the OP has is to simply cut the wires for the speeds they don’t want used. That would mean the if the fan is set to High or Medium it’ll turn off. I don’t know if that option is worthwhile, but it might be easier.

5

Ok thanks for helping, I appreciate it.

So basically what I do is

  1. Find & identity the incoming hot wire
  2. Cut the 2 wires that’s going to the medium & high speed settings on the motor
  3. Connect these 2 cut wires to the slow speed
    Side of the motor, so now I would have all 3 wires connected to the slow side of the motor
  4. Now when I select either slow, medium, high
    On the switch the fan would run in slow speed.
    Does this sound correct?
    Thanks
6

pdf drawing

It assumes the order of the rotary switch is off → hi → med → lo.

If the order is off → lo → med → hi, it should be pretty obvious what to do.

7

Thank you!

8

Color me curious, but may I ask why? I mean, wouldn’t it be a more flexible approach to just use “low” for low and keep your other options open?

9

I’m going to take a WAG and speculate that the OP has “someone” who thinks the fan should be running at a higher speed. But, even with that consideration, I would be reluctant to mess with the wiring. At best, everything is fine. But there is that very small chance that something gets screwed up. And you never can tell when you might want the fan to run on high (e.g., clearing smoke or dust from a room, ventilating an area while you’re working, A/C goes out or it’s a super-hot day). I also think about what I’ll do with the fan if I no longer need it. My conscience wouldn’t let me donate it or gift it to someone, even if I put the wiring back the way it was originally. Just saying.

Finally, what if the worst possible thing happens and the fan someday causes a fire? Even if the reason for ignition is NOT related to the modification, the investigators are going to figure out that the fan was tampered with. That’s not a good thing.