Replace 3 wire fan with 4 wire fan ?

Fixit7 · 03-07-2014, 10:14 PM

I got the wrong fan. It is one for cooling the computer chassis instead of the cpu.

The new one has a 4 wire connector while the old is 3 wire.

Can I use the new one in place of the 3 wire fan for the chassis fan ?

New fan does draws twice the amperage of the old.

Andy

Drakeo · 03-08-2014, 08:01 AM

yes you can if it plugs in ok and the ground and power is right test it. the fourth wire is for the control sensor it will slow it down and speed it up for quite operating. you will have one speed.
. I have done this before. remember keep your self grounded and connect it before you turn on the power that way if it is wrong the board will not go live and short out. it will just do anything. if you fiddle with it with the power on you will!!! break things,

Fixit7 · 03-08-2014, 01:17 PM

Thanks.

I disconnected the CPU and then started it up.

Fan works great.

Andy

cascade9 · 03-18-2014, 12:38 AM

Quote:

Originally Posted by Fixit7

I got the wrong fan. It is one for cooling the computer chassis instead of the cpu.

The new one has a 4 wire connector while the old is 3 wire.

Can I use the new one in place of the 3 wire fan for the chassis fan ?

Could be taken various ways (are you going to use the new fan on the CPU or are you going to use it as a case fan?)

But replacing a 3 wire fan with a 4 wire fan is not normally an issue. Though there can be issues with some non-stardard fan wiring used on some big corporate systems (e.g. dell)

Quote:

Originally Posted by Drakeo

yes you can if it plugs in ok and the ground and power is right test it. the fourth wire is for the control sensor it will slow it down and speed it up for quite operating. you will have one speed.

Nope.

Most 4 wire fans are 'PWM' fans. The 3rd pin is the speed sensor, 4th pin is for the PWM function. Fan speed can still be controled by changing input voltage.

http://en.wikipedia.org/wiki/Fan_control

cgtueno · 03-28-2014, 06:56 AM

Hi

Just a word of caution.
Ensure that:
.the fan can achieve the required RPM. A slow fan could create a very inefficient (an ultimately costly) cooling problem.
.the fan's bearings are sufficient in both design and quality (or you will end up prematurely wearing out the fan)

Just because it is electrically compatible, doesn't mean that it is a viable, or long term solution.

Regards

C.