Newbie question about 12Vdc fan

[tormod]

Hi there,

I have a network switch and one of the fans has stopped working so I want to replace it. The exact model of the current fan is this 12V one http://nz.element14.com/sunon/mb40201vx-0000-g99/fan-40mm-green-12vdc/dp/1824261

Does anyone know how I can tell which other fans would be compatible? If it is 12Vdc is that enough or do I need to worry about watts/amps etc?

 

[(*steve*)]

You need one that will physically fit, and have roughly the same flow rate (err on the side of greater flow).

It must be a 12V fan, and the current drawn will probably be similar and acceptable if you follow this advice.

 

[tormod]

Thanks Steve - I've found similar 40mm fans that are 12V. What about things like ball vs sleeve bearings? I also notice that some fans have 2 wires, some have 3 and some have 4. Can a fan with 4 wires be modified so that it works with a 3 pin connector?

 

[Colin Mitchell]

A ball-race is best. It must have the same number of wires or 2-wires will work with all arrangements.

 

[(*steve*)]

I'd probably go for fluid dynamic or magnetic bearings if they are available. Otherwise, as Colin has suggested, from the two alternatives you have given, ball bearings are better.

And go for the same number of wires. As Colin also suggests, a 2 wire fan will work, but it will always run at full speed and will not offer ay speed feedback to the unit. This will at least cause it to be noisier, and may cause other problems.

 

[elebish]

Hi there,

I have a network switch and one of the fans has stopped working so I want to replace it. The exact model of the current fan is this 12V one http://nz.element14.com/sunon/mb40201vx-0000-g99/fan-40mm-green-12vdc/dp/1824261

Does anyone know how I can tell which other fans would be compatible? If it is 12Vdc is that enough or do I need to worry about watts/amps etc?

If it has the same voltage and current ratings and moves air in the same direction as the old fan, it will probably work.