Hooking up two 800RPM fans to one 3 pin connector

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CountChoculaBot
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Joined: Mon Jul 23, 2007 3:48 pm

Hooking up two 800RPM fans to one 3 pin connector

Post by CountChoculaBot » Sat Dec 01, 2007 7:49 pm

Is it safe to hook up two Slipstream 800RPM fans to one 3 pin mobo connector with this?
http://www.performance-pcs.com/catalog/ ... ts_id=1311

This'll be on an X38 Maximus Formula mobo btw. I want to be able to use speedfan for all my fans but unfortunately I don't have enough headers so this is my last resort =\ I heard somewhere that X38 specs give 3 pin headers more than enough power for a single normal fan, so I was thinking that it could run two 800 RPM fans :D I'll probably do this to multiple 3 pin headers on the mobo.

Also, speedfan will be able to control the speed of both fans right (not independently, of course, since that's hoping a bit too much :D)?

Wibla
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Post by Wibla » Sat Dec 01, 2007 8:14 pm

The Maximus Formula has 8 fan connectors, all adjustable according to asus.com .. what kind of setup is this? hehe.

But answering your question, this shouldnt be a problem at all.

I'm running a Scythe Kama Bay with stock 800rpm scythe fan piggybacked off the Molex connectiors on my Nexus 120mm fan for the cpu, working flawlessly, giving more airflow over the right areas when needed :)

Those fan headers are made to handle alot more than a slow 120mm fan will use.

Felger Carbon
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Re: Hooking up two 800RPM fans to one 3 pin connector

Post by Felger Carbon » Sat Dec 01, 2007 9:03 pm

CountChoculaBot wrote:Is it safe to hook up two Slipstream 800RPM fans to one 3 pin mobo connector with this?
Yes, it's safe. If you want the tach (RPM) signal to work on one of the fans, you need to cut the tach wire to the other fan. Having both connected to the same wire makes a mess of things.

If the wires are color-coded underneith the sleeving, there'll be a black wire connected to pin 1 - that's ground. There'll be a red wire on the middle connection, pin 2 - that's +12V power. The tach signal will be on pin 3 and is most commonly yellow, although any color other than black or red is OK.

Avoid the 3-pin wyes available at Case-mod.com. Not only aren't they sleeved (how they keep the price to 99 cents), but all three wires are blue. No color coding at all! So you'd have to refer to the wires connected to your fans to figure out what wire was what. And still cut one but only one tach wire.

CountChoculaBot
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Post by CountChoculaBot » Sun Dec 02, 2007 7:18 am

Thanks for the replies.

After cutting the RPM wire to one fan, speedfan can still control the speed of both fans right?

Felger Carbon
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Joined: Thu Dec 15, 2005 11:06 am
Location: Klamath Falls, OR

Post by Felger Carbon » Sun Dec 02, 2007 7:36 am

CountChoculaBot wrote:After cutting the RPM wire to one fan, speedfan can still control the speed of both fans right?
Yep.

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