How to power fans for server cabinet?

Russinating · 3 Apr 2017 at 14:51

The server cabinet's's got two 120mm fan mounts on the roof but obviously I can't just plug them straight into the mains. Is there an adapter or converter of sorts to utilise two spare fans I've got or do I need to buy some specific ones that can be mains powered?

Sp00n · 3 Apr 2017 at 14:55

Do they not have a mains plug on them?

Russinating · 3 Apr 2017 at 14:55

They're PC fans that I've got leftover so they're just 3-pin molex or whatever you call it.

Sp00n · 3 Apr 2017 at 14:59

You can get fan connector > usb adapters, or a usb fan controller, or a 12v transformer or just buy some proper fans.

d_brennen · 3 Apr 2017 at 15:02

Fan header extenders and plug them into the chassis fan headers of one of the servers?

Russinating · 3 Apr 2017 at 15:20

There's no server in the cabinet just a switch hence no internal fan connectors etc to come off. If I get a USB to fan cable can this just then be plugged into a standard USB plug like a phone charging cable?

Sp00n · 3 Apr 2017 at 15:22

Russinating · 3 Apr 2017 at 15:37

Ok next potentially stupid question... can a fan controller by powered by a USB plug via a USB->molex adapter? To then act as the the power source for the 2 fans plus control/temp/etc.

bremen1874 · 3 Apr 2017 at 16:36

Is a single switch going to generate enough heat to require additional fans?

Deleted member 77746 · 6 Apr 2017 at 08:14

bremen1874 said:
Is a single switch going to generate enough heat to require additional fans?

Defo not. Waste of time and money IMO.

bledd · 6 Apr 2017 at 12:50

You're going to have to make something.

If using USB, you can run the fans from this, but they'll be running at 5v. I use this for my Synology cooling box. Find an old thick USB cable, chop the end off and solder the red/black wires into a female molex plug.

Like this..

This will be a 5v fan header, so it's slower than normal, not all fans can start at 5v, test them..

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Or you could buy a 12v DC PSU, chop the end of the connector off and solder that into a female molex header.

http://cpc.farnell.com/powerpax/ptd...-GEN-SHOPPING-POWERPAX-Power_Supplies-PW02358

bremen1874 · 6 Apr 2017 at 13:58

It's easy enough to find power supplies with molex connectors already attached. They're used for powering HDDs when you're using IDE/SATA to USB adapters.

blueacid · 6 Apr 2017 at 14:10

If you've got any old home electronics, like a router or cordless phone etc check the power supply. Often they're at 12 volts: perfect! Cut off the old barrel connector and solder on a molex, call it a day.

Although I agree, if it's just a switch in there it'll not produce enough heat to be worth the effort.

Liquidfox · 10 Apr 2017 at 14:40

If you haven't got a server in there, why do you need fans?

Rroff · 10 Apr 2017 at 14:42

I've a similar setup and straight 5V USB wasn't enough to get the fans anything like doing something worthwhile - had to stick a boost converter in there to get it to 12V.

EDIT: This is what I use:

Grabbed a 5V USB to 9V and 12V switchable boost converter from Amazon and made a little box (gotta love the hot glue gun) with 2x 3 pin fan headers - can supply around 12v at upto 2amps with a good enough power adaptor so enough for 2 fans and can run it at 9V to reduce noise (7.5V would have been better really).

bremen1874 · 10 Apr 2017 at 16:56

What a perversely complicated way of powering a couple of fans!