Advice - vary speed of 240v 18w 80mm fan

[TonyChapple]

Morning everyone!

I would really appreciate some advice please.
I've bought a small 240v 18w fan to help circulate air in plastic box used for drying food (biltong!)
Could someone advise me on the best way to vary the speed of the fan?
all the fan controllers I've seen dont seem to work on fans as low as 18w

So..... Anyone have any suggestions?
much appreciated
Tony

 

[telectrix]

you could try it on a dimmer switch. might work, might not, but a small expense as an experiment.

 

[TonyChapple]

Thanks telecritx - sensible suggestion.....
i had read on tinternet that fans and dimmer switches don't always work ... But as you say - cheap experiment!!

Any other adivce from others?
Cheers
tony

 

[Engineer54]

You can get exactly the same face plate fan speed control, as a straight dimmer. Most domestic fans are only 40W motors, so they should be able to control an 18W fan.... other than that, as you say, try Tel's suggestion...

 

[Marvo]

Where you located Tony? Biltong isn't a thing they'd know much about in the UK

Can you attach a picture of the fan motor?

Fan speed controllers are usually rated by the maximum motor size they can handle, they can often be used on motors much smaller than the value they're rated at.

If you're going to try using a lighting dimmer for speed control I would use a dimmer with at least 5 x the capacity to accommodate the higher starting current and the fact a motor is an AC3 (highly inductive) load.

Whatever you do to reduce the speed I would only go as low as half the original speed. If you go too low the motor will overheat especially if it TEAO

If you can post a picture or two or give us a link to an datasheet for the fan on a website you'll get better advice.

 

[D80]

Will a lighting switch dimmer not damage the motor?

 

[Marvo]

The only difference between some fan speed controllers and some dimmers is that the speed controller is configured to reduce the speed by a maximum of about 50% whereas a lighting dimmer will go down to almost zero. A dimmer can damage the motor if it's set too low for the cooling to be effective.

 

[TonyChapple]

Sorry for not replying sooner!
My biltong project is still ongoing....
The fan is 70mm diameter, about 40 mm deep from RS
it has a stock no. 509-030 (can't find on Internet) the sticker on the fan says
240v a.c. Fan
50/60 Hz 18 watt
Impedance protected
Case must be earthed
Made in west Germany

Could really do with some help !!!
Cheers tony.