Industrial Ceiling Fans - Speed Control Issue

Poorle · Apr 27, 2013

Hi Guys,

I have two ceiling fans and a speed control unit which switches on the fan and allows you to control the speed of the fans. Speed Control Unit Model is RV-05 2A max, 480W - with Forward / Reverse and OFF switching.

I only have T&E from the switch to each fan (2 x Switched Lives which are connected together to make both fans live when switched)

I have left the Reverse function disconnected (as I don't have 3-core and Earth cable installed) at both the Speed Control Unit and the Fans, so all I'm left with is switched Live "Forward".

It's fed from a 5A Fused Connection Unit.

Problem is that one fan is running at a considerably faster speed to the other one. When I turn the potentiometer on the switch to lowest setting, one fan is faster than the other.

To solve the problem I thought about disconnecting the switch wires and taking one pair of switch wires to another switch next to the existing switch, so effectively I will have one switch for each fan - but before I do that I'd like another opinion please!

Thanks

Paul

Jimsparky · Apr 27, 2013

Might be worth checking if the spindle for the pot is in the correct point of the shaft ?? Maybe you think you have it turned right down on the dial but you actually haven't ?
Have you checked voltage out of the two ?

Poorle · Apr 27, 2013

Jimsparky said:
Might be worth checking if the spindle for the pot is in the correct point of the shaft ?? Maybe you think you have it turned right down on the dial but you actually haven't ?
Have you checked voltage out of the two ?

Hi Jim thanks for reply - well the pot seems to be working correctly as I'm getting a value between 100v - 240v at each fan depending on the position of the pot it's just one is spinning faster than the other and they're currently both switched together.

Do you think it could be something to do with the way in which it's wired?

Here's how it's wired up -

Marvo · Apr 27, 2013

What type of speed controller is it ie resistive or PWM? Make and model number of the fans and the speed control would be great. If not then can you give us any photos?

Knobhead · Apr 27, 2013

Connected like that, put you’re marigolds on and clean the slow fan.

spark 68 · Apr 27, 2013

Modifying to two switches would not solve your problem, you only have one speed controller.
All this would give you is two independently switched fans.

You would need two speed controllers and two switches or a DP switch to give independent speed control to each fan.

As the others have said try checking the bearings are free to turn.

Poorle · Apr 28, 2013

Model FANTASIA RVO-5 COMMERCIAL FAN CONTROLLER

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Poorle · Apr 28, 2013

Hi, i do have 2 switch wires available- so could get another speed controller to control the second fan i think that may work?

When i first powered up both fans together, one was barely moving on half power and was flying. can't leave it as it is!

Poorle · Apr 28, 2013

I know it's connected up a different way but the manufacturer's wiring diagram showed the RVO-5 connected up with 5 fans in paralell (using 3 core and earth mind you as one function is reverse which i left disconnected) and i've got it in paralell at the minute. Can't really change the cables in walls..!

Marvo · Apr 28, 2013

If one fan is running faster and both fans are on a common controller then check the wiring again in the fans themselves. The problem with ceiling fans is they run with massive slip to the point of practically being in stall condition. This makes accurate speed control very difficult and there's likely always going to be a speed difference.