Capacitors for ceiling fan speed control

I have a 240VAC Vent Axia ceiling fan and a C-bus fan controller. I need to know what capacitors to use. Does this depend on the make and model of the fan?

I have been trying to find info to no avail, so any thoughts welcome. The fan controller came with capacitors fitted, but not sure if they'll work with my new fan.

 

The idea is that you use the capacitors that came with the fan. Normally this is a single 3 terminal block with 2 capacitors and a common that you remove from the fan and install in the Cbus controller. However the controller is designed so you can connect up 2 external capacitors for low and medium speed.

 

The fan didn't come with a controller unfortunately, so I'm trying to work everything out by myself. Struggling to even find any specs or details for a controller that I can reverse engineer.

 

Assuming you are certain it is an AC induction motor fan and not a DC brushless fan you can hook it up with the existing capacitor block in the controller and see if the speeds work for you. Most ceiling fans use similar values.

 

Perfect, that's exactly what I wanted to hear!

Yeah it's definitely a AC induction motor.

Just read horror stories about capacitors overheating etc, but if you think it'll be fine I'll take your word for it mate cheers!

 

Given the fan controller came with capacitors you can be reasonably confident they are motor run capacitors. Their value will just alter the speeds you get. The only issue to be aware of is if one capacitor is too small in value it may run too slowly or not at all.

What are the markings on the capacitors?

 

Please see below:

https://www.tradesparky.com/heating...s/sweep-fans/va-428049-hl90-ceiling-fan-900mm

 

What do you reckon then?

 

The capacitors when switched into the circuit by the fan controller are in series and simply alter the reactance of the circuit and hence you end up with a different speed.
Reactance is akin to resistance in an AC circuit.
So though the capacitors you have are not primarily designed for that fan, I would try them and just check the speed 1 and 2 to ensure its not too slow.
There is theoretically the chance that you could get an increase in speed, but highly unlikely read up on resonance in AC circuits, but it does get involved.
Quick check if your concerned measure the voltage across the capacitor and across the motor windings only if you are really competent and know what your doing, less than supply voltage across each component is acceptable.

 

Thanks for the reply. Much appreciated.

I kinda know the theory behind it all. It's just that I've read that if the caps aren't correct it can cause the motor to generate excessive heat etc. Not sure if it's true or not, but I always like to approach stuff like this with an abundance of caution.