Slowing Down A Fan

[USchabon]

I have a 10" fan that runs fast, super fast and warp speed. Is there a regulator I could use to lower the voltage it gets so that it draws less and runs slower?

Main thing is cheap safe and durable since I want to plug it and forget it, but a dial knob and an on off switch that I could run about 4-6 feet from the plug, or 3 feet from the fan would be awesome of under 10-20 bucks.

Glad to build it too, would be a nice little beginner's project actually.

[stj]

Re: Slowing Down A Fan

depends on the type of motor

[artstv1]

Re: Slowing Down A Fan

Install a dimmer switch in the ac line.

[R_J]

Re: Slowing Down A Fan

Dimmers are for dimming lights(resistive load) they are not for controlling a/c motors (inductive load)

[rhomanski]

Re: Slowing Down A Fan

I had an overhead fan in my living room on a dimmer switch, worked fine. Had the same kind on my whole house fan. They used PWM and and never had a problem with them.

[kaboom]

Re: Slowing Down A Fan

I had an overhead fan in my living room on a dimmer switch, worked fine. Had the same kind on my whole house fan. They used PWM and and never had a problem with them.

They do not use "PWM." It's phase angle control.

Just because you've never had a problem doesn't mean you didn't do a hack job- the proper control is a fan control, not a "dimmer."

A common "light dimmer" control has only two wires; it derives its trigger signal through the load (it can because incan lamps are resistive) during the "off" time.

A "fan control" has an extra wire for control power. These do not derive the trigger via the load return; they cannot because the load (fan motor) is inductive, which disturbs the symmetry of the triggering.

Put a "light dimmer" on a motor and the triac is triggered asymmetrically. Tell me, how does an induction motor deal with the effective DC offset? The motor "rumbles" and hums. If the core saturates, the triac blows, usually one half. Once that happens, you put DC straight into the motor.

Again, tell me how that'll go...

Don't post "hack stories" and misguided "advice" to new members and expect some kind of reward; this isn't betanews.

Oh, I've screencapped this post should it "disappear by accident," as others have...

[budm]

Re: Slowing Down A Fan

https://cdn.badcaps-static.com/pdfs/...224bd7f185.pdf

http://www.kbelectronics.com/Fan_Spe..._Controls.html

We still do not what kind of Fan he has.

[rhomanski]

Re: Slowing Down A Fan

I didn't tear it apart and check it out. Just read the package. It said it was safe for fans and it had, I'm thinking, 3 wires. It was twenty years ago. It wasn't a hack job.

[kaboom]

Re: Slowing Down A Fan

I didn't tear it apart and check it out. Just read the package. It said it was safe for fans and it had, I'm thinking, 3 wires. It was twenty years ago. It wasn't a hack job.

Sounds like the right one.

But don't call it a "dimmer," it just adds confusion... I only made a "big deal" over it because our stupid locals think there's no difference and use the part that's "cheeper."


It may have the same triac and variable trgr ckt as a "dimmer," but it's not the same thing.

We still do not what kind of fan he has.

You don't put a "dimmer" on a motor, period. You use a "fan control," (or variac, or resistor bank if long ago) and not haphazardly either; never with a "split-phase" motor with a start switch. Run them too slow and the start winding never gets switched out!

On PSC or shaded pole motors, they're usually OK. For a single reduced speed, an AC rated cap in series will also work.

[rhomanski]

Re: Slowing Down A Fan

It was expensive, became a pain in the a$$ too. I was trying to put door stops and brass plate light switches on at the same time. The only plates were three gang regular holes. I put two rectangular "fan control/Dimmer" with the one switch. I had to drill holes and nibble and finally file it square. Took a couple months to replace all of them plastic switch plates. The house was new and needed a lot of little touches. Towel racks and toilet paper holders too.

[budm]

Re: Slowing Down A Fan

Sounds like the right one.

But don't call it a "dimmer," it just adds confusion... I only made a "big deal" over it because our stupid locals think there's no difference and use the part that's "cheeper."


It may have the same triac and variable trgr ckt as a "dimmer," but it's not the same thing.



You don't put a "dimmer" on a motor, period. You use a "fan control," (or variac, or resistor bank if long ago) and not haphazardly either; never with a "split-phase" motor with a start switch. Run them too slow and the start winding never gets switched out!

On PSC or shaded pole motors, they're usually OK. For a single reduced speed, an AC rated cap in series will also work.

That is my point since he did not identify what kind of fan he has and people start suggesting using light dimmer without knowing what kind of fan it is before giving the answer such as post 3. Post 2 asked OP the right question.
If he indicates the AC in the beginning then he could have gone to the KB link I provided, LUTRON website also indicates not to use dimmer with inductive load, they also make FAN speed controller. If it is DC motor (what type of DC motor)) then another kind of controller (PWM, etc.) will be required. Not completed info does not help.
BTW, I did not suggest to use light dimmer either.

[USchabon]

Re: Slowing Down A Fan

Hello guys. Sorry about the delay. here is a photo of the motor.

[USchabon]

Re: Slowing Down A Fan

BTW, I have no clue what kind of motor that is, that is why I posted a photo

[kaboom]

Re: Slowing Down A Fan

BTW, I have no clue what kind of motor that is, that is why I posted a photo

C-frame shaded pole motor- perhaps the most common "modern" small fan motor...

[USchabon]

Re: Slowing Down A Fan

Cool, thank you for your replies.

Just cause I am a bit of a noob and I don't want to make the wrong purchase, what would be the best way to control the speed on one of these (and hopefully be able to turn on/off and control from about 3-4 feet from the fan itself)?

[budm]

Re: Slowing Down A Fan

Just do the search for 'shaded pole motor speed control'.
You may also be able to find one with wireless remote control too.

[sam_sam_sam]

Re: Slowing Down A Fan

Where I work we have a air dryer that the system was going on and off to fast because
The condenser fan was running to fast it has a fan motor very similar to your fan the only difference is that this motor is sealed to keep the dirt out

You can find motor controller for this type of motor
On these controllers you have to adj the min speed pot so the
motor run smooth other wise the motor will not run and may over heat

Here is where you can find one not from Johnstone Supply but the company that makes the controller

I hope this helps

I have use these before and they very good

https://m.johnstonesupply.com/storef...ep?pID=G22-731