Cooling Fan Power

[Nono]

I am planning on buying some fans for my power supply and plan on running them off of the capacitors for the motors..... My cap voltage is 33.6 vdc so do I use a fan with a higher rating like 48vdc or will a lower voltage fan like a 24vdc fan take the power? I think that the 48v fan is what I need but will this fan burn out because inadequate voltage?

[Al_The_Man]

If you intend buying, why not go with one 5" or 6" 120vac around 100-120cfm
http://www.blowerwheel.com/fans-cool...med-square.htm
Surplus are available and you do not have to dick around with two or three 2" fans that may be low cfm and maybe intended for lower wattage supplies.
Most industrial cabinets use 120vac type.
Al.

[Nono]

I considered using an ac fan but have access to dc fans at .99 to 2.50 each. Also would like this fan to leach off the capacitor after shutdown.

[sendkeys]

seeing your only using 33 volts you should be able to use a voltage regulator from radioshack with any 12volt computer case fans. should only be couple bucks.

Just a idea

[Nono]

Back to the question,, Can I use a fan with a higher rating like 48vdc or will a lower voltage fan like a 24vdc fan take the power with a 33 volt cap?

[Al_The_Man]

Can you even get a 48vdc fan? A 24v on 33 will turn a bit faster and maybe have a bit shorter life, but I would imagine there is quite a bit of tolerance on the voltage rating. Or use three 12v'ers in series.
Al.

[Nono]

Al 48v .23a 120cfm 48db(like a lawn mower).. Do you recomend a 24v instead of a 48v fan. I could try both and find out the life span for all to know.
Any recomendations on a timer/counter for power on time?

[Al_The_Man]

Most of the current DC fans are brushless DC which have electronic switching inards.
So They may not take to high variations of voltage compared to thier older brush type counterparts.
For a Hours Run meter, I would go with AC because of the accuracy, you can pick them up on ebay for around $10.00. If you have a powerup/e-stop relay, you could use a spare n/o contact to switch the 120ac.
Al.

[Nono]

Did anybody notice radioshack.com is gone? Al I will keep an eye out for one. will I need to run it through a relay? shouldn't I run it off my main ac on switch? It would be for mtbf's for the controller components not the machine itself. As for the machine I would want it set up off spindle power to start the timer wouldn't I?

[Al_The_Man]

Originally Posted by Nono Did anybody notice radioshack.com is gone?

I found out the day they switched over to CircuitCity, but I though they had only closed in Canada.
You could put the hours-run across the power transformers 120v in.
Al.