using fan controllers on boxed in fan(expanding foam)

[tdsan]

HELP

i will be using sms twin fan controllers on my new project. i aslo intended to box my fans in(the leppy way )using expanding foam.i have read on various post that running fans lower than 40-50% will cause them to malfunction, over heat and set on fire. as they are self cooled.

now 2 8 inch rvk's wrapped in cling film,covered in expanding(highly flamable)foam packaged in a cardboard box dont sound to appealing.

please help me!!

[Guest Shlozi420]

Dont know about them setting on fire or malfunctioning. My sms com keeps the noise down and keeps the air circulation god during the night with enough negative pressure. If you fans are half decent they should be fine mate

[tdsan]

how low do you run your fans at when the lights are off??

[Guest Shlozi420]

the temp probe for the sms slows them down to a steady pace mate. You can manually set your desired speed too

[scraglor]

hah, gotta love a bit of chinese whispers, it was I that pointed out the fact that you shouldn't run fans below a certain voltage some time ago, nothing will set on fire for a start!! metal doesn't burn very well!

if you supply your fan with a voltage thats too low to make the rotor spin, then yes this can actually damage the windings of the motor... however, if you're doing this, then your fan wont be moving any air!!! so it'd be a bit pointless having a fan!! at around 30-40% supply voltage, your fan will be producing so little air pressure and flow, you'll have zero cooling, and you grow room will be leaking smells and your plants will be starved of co2!!. so you shouldn't be running your fans this low anyway

as for putting the fan in expanding foam, again this makes no difference to the fan, as the motor is suspended in the centre of the fan, in the middle of the airflow through the fan

[ilikebigbuds]

On 1 November 2011 at 11:42 PM, scraglor said:

hah, gotta love a bit of chinese whispers, it was I that pointed out the fact that you shouldn't run fans below a certain voltage some time ago, nothing will set on fire for a start!! metal doesn't burn very well!

if you supply your fan with a voltage thats too low to make the rotor spin, then yes this can actually damage the windings of the motor... however, if you're doing this, then your fan wont be moving any air!!! so it'd be a bit pointless having a fan!! at around 30-40% supply voltage, your fan will be producing so little air pressure and flow, you'll have zero cooling, and you grow room will be leaking smells and your plants will be starved of co2!!. so you shouldn't be running your fans this low anyway

as for putting the fan in expanding foam, again this makes no difference to the fan, as the motor is suspended in the centre of the fan, in the middle of the airflow through the fan

Yeh bang on here, I messaged systemair a wee while back whilst I was putting an extraction plan together and they confirmed anything below 80v and a centrifugal fan with a capacitor can and will overheat, so 80v would be in the mid 30% mark. 5 step voltages are as follows step 1 110v (47.8%) step 2 140v (60.86%)step 3 170v (73.9%) step 4 190v (82.6%)and step 5 230v (100%). Hope this helps someone.