PC Fans for beer fridge

[private4587]

I have recently bought two of these to place in my brew fridge, 3 pin motherboard and 4-pin (molex) power input connectors for better compatibility. My question is I know I have to cut off plugs but which wires to use to power for 12 v.
Thanks
Peter

 

[terrym]

Am I being naive or stupid, but isn't it a case of just putting a meter over the terminals you want to use and establishing which ones give you 12v or thereabouts. Then use these to find out which way the fan turns (assuming the fans take 12v) and then select the polarities to drive the fan the correct way.

 

[Dr_Unkenly]

Yellow is +12V and black is Ground.

 

[cheapbrew]

Black is usually ground but depending on the manufacturer of the fan it could be red or yellow wire for 12v so its best to check with a meter like Terry said.

 

[Dr_Unkenly]

Yellow is +12V and black is Ground.

That's the standard for a 4 pin Molex.

If it's just got the 2 wires coming off the Molex with any random colour scheme then the outer pin is the +ve and the inner one is the ground.

You won't get a voltage reading off a meter unless the fan is powered up.

 

[foxbat]

Google "pc fan pinout" and select the "Images" tab.

Tip: the 3 and 4 pin fans have a small circuit board embedded in the fan casing. Applying 12V to the wrong pin will even for a millisecond will kill it dead so be careful with dangling wires :)

 

[Dr_Unkenly]

Google "pc fan pinout" and select the "Images" tab.

Tip: the 3 and 4 pin fans have a small circuit board embedded in the fan casing. Applying 12V to the wrong pin will even for a millisecond will kill it dead so be careful with dangling wires :)

Sensible advice right there.

I'd just like to add that the 4 pin Molex isn't connected to the fan's control circuit board. It is designed to plug directly on to a PSU only so don't worry.

 

[nelviss]

i build and mod pc's, and the previous reply's are confusing, but usually its red live(+), black ground(-) and yellow is always the speed sensor.

 

[dan125]

i build and mod pc's, and the previous reply's are confusing, but usually its red live(+), black ground(-) and yellow is always the speed sensor.

You're right they are a bit confusing - I just got one of these
http://www.akasa.com.tw/search.php?seed=DFS802512L
to replace a 2 pin fan.
Do you think the red is the live?

 

[Bigcol49]

Hi!
The easiest solution is to avoid fitting the fan in the first place. I have a brewfridge that holds two FVs and get excellent results from convection alone.

 

[dan125]

Hi!
The easiest solution is to avoid fitting the fan in the first place. I have a brewfridge that holds two FVs and get excellent results from convection alone.

That's what I've been doing for ages, and have just installed the fan as a cheap upgrade after some reading up.
The 1st fan I had was nice & easy with only 2 wires, but whilst tinkering it lasted about 5 mins before I cut the tip of a finger and broke a blade in the process

 

[nigelnorris]

Most [but not all] fans have built in polarity protection, and the likelihood of burning out a fan by connecting with wrong polarity is much exaggerated. I have always just connected them up and if they don't work right then just connected them the other way around, and have never experienced a burn out. I'm not recommending that you do it because there is a possibility that you'll damage the fan, but it's fairly unlikely.

 

[Bigjas]

I'm another one who doesn't use a fan. I have an under counter fridge and like Bigcol49, I get great results just relying on convection alone. I understand why you might want to use a fan and realize it would be better, but personally I don't think its necessary in such a small area.