Compatibility between ceiling fan and speed controller

[Simon47]

I have a ceiling fan which currently has a remote control for fan speed and dimming the attached lights.
We're currently doing some works in the room, and I have the opportunity to add switches by the door. As SWMBO has trouble reaching some of the standard/table lamps, I'll be adding switched sockets for some of those - instead of the plug-in remote control units we currently use. Basically, I'm looking to get rid of two of the remote controls we have hanging around.
Because of the number of switches/dimmers, I'm looking to use a grid system.

The fan is by Fantasia (I picked it up cheap at a charity shop), and they offer a number of remote controls (e.g. this one) - but none of them would fit in with using a grid switch. Varilight have a "dimmer" unit sold specifically for fans.
Fantasia's FAQs say "A wall mounted variable dimmer switch must not be used to adjust fan speeds". It's hard to know whether this is no more than a case of not wanting to deal with queries from customers trying incompatible dimmers, or whether there's a specific technical reason.

I've asked Varilight, and they don't know. All they can do is speculate that the motor is designed for set voltages rather than coping with variable ones - which I find hard to believe. And they add that I should ask Fantasia.
I've asked Fantasia and they don't know. All they can tell me is that the only controls they've tested are the ones they sell.
The main difference is that it's clear the Varilight unit chops the waveform - it'll just be a version of their dimmers optimised for motor control. It's not clear if the Fantasia ones chop the waveform or use an inductive/capacitive dropper.

I could buy the Fantasia unit, and transplant the module to a grid, but the information they've told me is that the unit is approx. 50mm x 50mm x 30mm deep. That suggests I might need to leave a blank space either side in the grid which will mean I need a bigger plate - assuming the module will fit at all.

Thoughts ?

 

[Lucien Nunes]

a ceiling fan which currently has a remote control for fan speed and dimming the attached lights.

What type of device is that?

 

[Simon47]

The current remote control is a black box with some wires coming out of it - I think it's an earlier version of this one The only clues I have as to it's method of speed control is that I can hear what sounds like relays clicking - so on changing speed, I can hear a faint click, then a second later another faint click, and in between it does seem like the fan is slowing. So I'm guessing that one click is a relay turning off, and the second click is a different one turning on.
At maybe 3" long 1 1/2" wide, by 3/4" thick, I guess there's room for there to be inductors or capacitors rather than a phase control circuit.
I'm assuming light dimming is by phase control, it's a fairly smooth dim.

 

[Lucien Nunes]

Depending on how many wires from motor to black box, the relays might be selecting different taps in the motor winding, a common method of fan speed control. If you hard-wired it to high-speed, phase angle control might work, but IME can cause annoying buzz from motors that are not intended for it.

Was your plan to bypass the controller and the integral light dimmer, and just wire the motor and light separately back to your wall control? I can't imagine the black box would be happy downstream of a phase-angle controller.

 

[Simon47]

Ah yes, details I should have included !
The black box has 3 output wires - common neutral, separate lives for motor (which has to be set to high speed on its switch) and lights.
Yes the plan is to remove the black box and wire the motor and lights back to the wall switch - 3C+E for common neutral and separate lives for motor and lights.

 

[Simon47]

Well, with the bank balance "a bit lighter" I now have part of the answer. This is the wall controller Fantasia sell :




So capacitive voltage dropper
Since it's a standard switch with shaft with flat on it, I reckon there's a good change the module will fit one of Varilight's grid adapters (they do them for a range of grid systems). I guess I'll need to buy some bits and see if it fits, and how many adjacent modules it's going to block.

I do like the way it's marked as not to be used for inductive loads ...

 

[Simon47]

So I start thinking along the lines of separating the board from the switch and either mounting it in the back if the box, or in a separate box in the attic.

And tgen I think, if I do that, just do away with the controller and run a 6 core (neutral, earth, lights, 3 fan speeds) cable to the fan. With one of those "doh, why didn't I think of that sooner" moments !
I'd just have to dive into the internal wiring to bring out the 3 speed tappings, and buy a suitable switch. I'll find another use for this unit.