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trying to replace capacitive ceiling fan control

I recently installed three ceiling fans in a warehouse space. Of the three units, one of them failed shortly after installation (the installer didn't know what he was doing and blew it up), and someone else replaced the wall controller with another unit. The replacement wall controller had a 4 position slider (Off / Low / Med / Hi* ) like the original, but I don't think it's exactly the same internally because in the "Off" position, the fan is still moving at a very slow rate (2-4 cycles per minute). Plus the slider goes the wrong way, but that's just cosmetic.

The fans have a single hot wire going to them (and a neutral coming back), so there's no fancy tach/feedback stuff going on here, just supply power manipulation.

I'd like to replace the failed controller with the exact same model by the same mfg (Rhine Electronic, Model UC9020, apparently Taiwanese) but their website is nonfunctional and I can't even figure out who their distributor in the US might be. So now I'm looking into at least getting a controller that works the same.

I took the failed controller apart and it is built around two large capacitors, labeled 8.0 uF and 12.0 uF (actually they're rated "uFJ", whatever that means). There are a few resistors, the 4 position slider switch and then that's it. I assume that this serves to cut the AC waveform or drop the voltage somehow.

If I go buy a replacement fan controller, what should I be looking for? Are there different types? (e.g. voltage limiting? current limiting?) All the failed controller label says is the current rating (1.5A). Obviously it is possible to get the wrong kind, because that's what I've got now.

Reply to
chris-google
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Obviously, the original fan controller switched the capacitors around to change speed. Typical for a split phase motor. And I don't think you can control a split phase motor's speed with just two wires... there has to be a hot and neutral, but also a third wire that connects to the appropriate capacitor. Many fans have the capacitor(s) inside the motor housing (designed to work from a pull switch hanging from the motor). Possibly is your fan of that construction? If so, a controller having the capacitors won't work.

I'd be very suspicious of the wiring to the fan. That is probably why the fan doesn't run with the original controller.

The replacement controller that you have is probably a "dimmer" type controller, and will not work with your fan. In my opinion, your first move would be to make sure that the wiring to the fan is correct. Unless the improper installation ruined the switch, it's unlikely that the capacitors are damaged. Most likely thing is that the improper installation ruined the fan motor by burning out the split phase winding. Prepare to buy a new fan or replacement motor.

--
Dave M
MasonDG44 at comcast dot net  (Just substitute the appropriate characters in the 
address)

Some days you're the dog, some days the hydrant.
Reply to
DaveM

DaveM ha escrito:

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In the case of a ceiling fan, you can control it using just two wires. How? Using a choke (reactance) with several taps. That=B4s the way it was done until very recently. The controller had 5 speeds, and the highest speed just bypassed the choke.

Reply to
lsmartino

Reply to
Craven Morehead

That looks like the controller I have -- two big caps, a few resistors, and a slider switch; NO ICs. Is this pretty much the only way to control a fan with one hot wire? If so then I'll just look for fan controllers that show only one wire going to the fan (and the neutral coming back).

Reply to
chris-google

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Question: what do I need to read to at least try to understand what you all are talking about -- split-phase motors, need for capacitor (or coil, as above?), etc?

(I used to know *some* EE stuff, phase, etc, but that was a *long* time ago.)

Thanks!

David

Reply to
David Combs

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gives a high-level overview of common AC motors.
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tells a bit more, including wiring diagrams.

--
Dave M
MasonDG44 at comcast dot net  (Just substitute the appropriate characters in the 
address)

Some days you're the dog, some days the hydrant.
Reply to
DaveM

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