• Please visit and share your knowledge at our sister communities:
  • If you have not, please join our official Homebrewing Facebook Group!

    Homebrewing Facebook Group

Fan problem - help with electricity!

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

redpat2061

Member
Joined
Feb 6, 2015
Messages
10
Reaction score
0
I built a tall collar for my keezer, so of course, the last foot of beer line gets warn and there is lots of head on my first pour. I bought a bilge fan

http://www.amazon.com/gp/product/B001O0DE9E/?tag=skimlinks_replacement-20)

and some pvc piping and used a 12V dc adapter i had lying around and followed a FAQ for cutting off the plug and wiring it direct to the bilge fan.

Worked great for a day, then the fan died and my beer got warm again. Turns out my 12V dc adapter was 500ma and the fan was trying to draw 2.5 a and this was bad (this is how much I DONT understand electricity).

So I read up on this and I think the internets are telling me that my voltage was right but my amperage needs to be equal to or greater than what the fan needs.

So I bought this: http://www.amazon.com/gp/product/B0023Y9EQC/?tag=skimlinks_replacement-20

So I wired it up just like the other one and... it doesn't work. Power is getting to the fan but instead of spinning like normal it's cutting in and out every second.

What is happening? Do I need exactly 2.5 amps to make this work?

View attachment 20150225_185710.mov
 
Last edited by a moderator:
Nope, if i reverse the wires it does the exact same thing. Which is weird cause i thought if the polarity was wrong it wouldn't work at all...
 
Just watched the video. It looks like the supply may be going into an over-current shut-down mode then kicking back on again...

Cheers!
 
In the video you can see a little black cylinder attached to the wire from the adapter. I can't figure out what the cylinder is for. Could that be what's making it do the overcurrent thing? Should I cut the cylinder off?
 
Blower has been damaged I think. Get a new one and put an inline 4 amp fuse and switch in your circuit.
 
I read through the customer reviews for the power supply and found this:

"11 of 12 people found the following review helpful
Does Not Work Properly Out of the Box
By Zhillsguy on March 12, 2013
Verified Purchase
I connected this to my new Lepai 2020+ amp, and it did not work. The amp's power LED was constantly fluctuating on and off. I verified it by checking with a VOM at the power tip with no load......the voltage constantly varies between about 7 and 12 volts.

The cost of returning this defective item is not cost effective, it's simply a loss."

Maybe the power supply is defective, try connecting it to something that is known to work and see how it behaves. I agree with jonbourg that an inline 4A fuse is advisable.
 
If you have a voltage meter add it to the circuit. If you loose voltage when the fan stops this would indicate the problem is the power supply. If you do not loose voltage when the fan stops it is probably the fan.
 
I'm sure it's not what you want to hear, but IMO, that high cfm fan is not a good solution. It's overkill for cooling a foot or two of beer line. More importantly, a 2.5 amp current draw (30watts@12v) will likely heat up the air as it is moving through the fan, resulting in diminishing returns.

A small, low cfm fan would be a better solution.
 
I've come across a fan problem as well. I bought a 3" computer fan , 12v DC, .16 A, and a 3v, 700 mA AC-DC adapter with a connector I was able to wire directly to the fan. The most I can get it to do after trying all combinations of switching the wiring and connector is get it to move about a quarter inch when I plug it, then it stops. When I unplug, it moves back that quarter inch to where it started. Is my adapter just too weak at 3v to make the 12v fan spin? I did not want to run it too fast, hence the low voltage adapter.

IMAG1059.jpg
 
3v is way too low voltage to run a 12v dc fan. Try at least 5v but even that may not get the fan to start on its own..

UP THE VOLTAGE

Cheers!
 
Back
Top