3-PIN fan into 2-Pin socket ?

[knowledge2121]

I am trying to replace the fan in my UPS since the stock fan is noisy. but the new fan I bought is 3 pin the stock fan is 2-pin...Can I connect the 3-pin to 2-pin ? or should i buy an adapter ?

 

[clutchc]

If you get the polarity correct and the fans are the same DC voltage, it will be fine. Basically the only difference is the 3rd pin is for RPM feedback to a motherboard BIOS.

 

[knowledge2121]

the voltages are the same but the stock has a higher current 0.3 AMP compared to the replacement which has 0.07 Ampere ... the replacement is a noctua with a max input wattage of 0.84 , the stock fan needs 12*0.3 = 3.6 watts ... should I use the ULNA adapter with the Noctua fan to reduce the inputted wattage a bit ?

 

[clutchc]

If the amp rating on the new fan is less, that is good. Simply means it consumes less power (watts). Probably different design, more efficient.

 

[knowledge2121]

but wouldn't it be dangerous if the inputted power is higher that the maximum wattage of the fan ?

 

[Paperdoc]

You've actually got it backwards.

First of all, do NOT worry about too high wattage. The VOLTAGE ratings match. So the new Noctua unit, given that voltage, will only allow 0.07 amps to flow through it, consuming 0.84W. It will not "allow" the UPS unit to push more Watts through it.

My real concern is that the UPS unit apparently used MUCH more power, and this strongly suggests it blows MUCH more air that the Noctua fan will. After all, the amount of air blown is proportional to the power in Watts used by the fan. You do not appear to have checked what air flow, in CFM, the original fan was rated for, and did not try to match that spec. Thus my concern is that you will have a quiet fan blowing not nearly enough air in your UPS, and it will overheat. You need to re-evaluate your choice of a replacement fan.

 

[knowledge2121]

the old fan has 1.1 m3/min airflow .... the new fan has 0.84 m3/min airflow

the fan is for a UPS that will be powering my rig. The MAX capacity of the UPS is 700VA ... assuming my rig consumes somewhere between 400-500 watts?, I think the UPS will not generate as much heat as when it is maxed out....right ?

 

[Paperdoc]

That is probably right. Judging from that spec, I'm guessing you have a 80mm fan.

Here are hints to help make the connections.
1. On a 3-pin fan, the Black wire on Pin #1 is Ground, and Red on Pin #2 is the +12 VDC supply. Yellow on Pin #3 is the fan's speed signal to be sent back to a mobo header which your UPS does not have, so just do NOT connect the fan's Yellow to anything.
2. On each fans case you normally will find two arrows. One shows the direction of rotation when the fan is wired correctly. If your fan rotates the wrong way, reverse the connections you made. The other shows the direction or air flow when the fan is working properly, so mount the fan into the UPS case accordingly.

 

[Paperdoc]

Thanks for Best Solution.

 

[Celo]

That is probably right. Judging from that spec, I'm guessing you have a 80mm fan.

Here are hints to help make the connections.
1. On a 3-pin fan, the Black wire on Pin #1 is Ground, and Red on Pin #2 is the +12 VDC supply. Yellow on Pin #3 is the fan's speed signal to be sent back to a mobo header which your UPS does not have, so just do NOT connect the fan's Yellow to anything.
2. On each fans case you normally will find two arrows. One shows the direction of rotation when the fan is wired correctly. If your fan rotates the wrong way, reverse the connections you made. The other shows the direction or air flow when the fan is working properly, so mount the fan into the UPS case accordingly.

OLD thread.

So you can keep the yellow cable and its socket/hole UNTOUCHED? Or just in case any need to cover the hole/socket of where yellow supposed to go in? Like sticking paper or tape or something similar.

 

[USAFRet]

OLD thread.

So you can keep the yellow cable and its socket/hole UNTOUCHED? Or just in case any need to cover the hole/socket of where yellow supposed to go in? Like sticking paper or tape or something similar.

No need to cover anything.
Just leave it.

And please don't dredge up ancient threads.