# Wiring several fans to one power source



## nish07 (Mar 16, 2008)

I'm no electrician and though I could probably figure it out, I was wondering if anyone could simply tell me how to wire several fans to one computer power source?

I'm looking at like 20 fans or so. Also, what would be good wire to use to extend the fan wires? I want to keep all three pins active as well so I can use a modulator to control the speed of the fans.

-Nish


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## onefstsnake (Jul 31, 2008)

Just connect the different colored wires to a single thicker colored wire.

Like 20 small red wires to a single thicker red wire...etc.


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## ofblong (Sep 11, 2008)

onefstsnake said:


> Just connect the different colored wires to a single thicker colored wire.
> 
> Like 20 small red wires to a single thicker red wire...etc.


not that easy. you cant just put 20 wires together and expect them to stay together, not start a fire, etc etc etc. The MAX wires you should put together is 5. with that said you can daisy chain it. take 4 red fan wires connect it to another wire. Take that extra wire and connect it to 3 fan wires and another wire etc etc until all 20 are connected. You cant put more wires together than will fit in the wire nut your using. I would wire nut them AND THEN heat shrink around that. Heat shrink will keep moisture out of the connections. With that said the limit for 1 12v Power supply last I looked was 10.

*edit oh and the "connecting wire" doesnt necessarily have to be "thicker". Just remember to wire all like colored wires together. red to red and black to black.


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## onefstsnake (Jul 31, 2008)

ofblong said:


> With that said the limit for 1 12v Power supply last I looked was 10.



10 what? 10 fans? 
Depends on what power supply is being used and the parts being powered by it.


The fans should not draw much current so heat in the wires should not be an issue.
A daisy chain would work as well.


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## Obliv79 (Oct 31, 2007)

ofblong said:


> not that easy. you cant just put 20 wires together and expect them to stay together, not start a fire, etc etc etc. The MAX wires you should put together is 5. with that said you can daisy chain it. take 4 red fan wires connect it to another wire. Take that extra wire and connect it to 3 fan wires and another wire etc etc until all 20 are connected. You cant put more wires together than will fit in the wire nut your using. I would wire nut them AND THEN heat shrink around that. Heat shrink will keep moisture out of the connections. With that said the limit for 1 12v Power supply last I looked was 10.
> 
> *edit oh and the "connecting wire" doesnt necessarily have to be "thicker". Just remember to wire all like colored wires together. red to red and black to black.



See Nish I already told you how to do it. Who's always right now?!?! lmao


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## nish07 (Mar 16, 2008)

I'm not convinced this is the best way and ideally these fans aren't going to be so near each other that I could cut the plugs off of them and wire any of them directly together without extending their wire with something else. It's just the manner of connecting them that I have an issue with. I don't know how many fans you could connect with a single power source, however, my pc power supply is rated at 500+W, so I assume it's enough to power quite a few fans. I just need some sort of schematic showing me which way I should go about connecting the wires together and then to the power supply.

-Nish


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## ofblong (Sep 11, 2008)

watts dont mean anything. You could have a 500w power supply that has 8amps on the 12v rail or you could have a 500w psu that has 40amps on the 12v rail. I thought you were just using a 12v transformer not a PSU. Just add up the amps of the fans. as long as they dont go over the amperage rating on the 12v rail you will be fine. Still be best to daisy chain them like suggested but not all in one huge clump of wires.


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## pl259 (Feb 27, 2006)

The location of the fans and your layout will dicate whether a "daisy chain" or "star" connection is best. Daisy chaining may save you wire but a single failure may take down the entire string of fans. Also, when daisy chaining, wire close to the supply carries the full current of all the fans. You'll need heavier wire. One way is to run heavier wire all the way from the supply to the location of the last fan. You just "tap" off at the points you need a fan. Kinda like you do with track lighting.

Star wiring, where you run a pair of wires from each fan back to the supply, can use more wire, but is more robust when it comes to failures. Another plus is that you can use a lighter gauge wire as it only needs to be large enough to handle the current for a single fan.

If you go with a star connection take a look at using a barrier block for making the connections. I'd also add an inline fuse if there isn't one already.

If you do decide to go star, let me know and I may be able to help you out with a barrier block or two.


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## ofblong (Sep 11, 2008)

good point on the fuse didnt think of that one. if you go the star route you could put all the wiring in some flex tubing as well .


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## Obliv79 (Oct 31, 2007)

As I stated in the chat with Nish it's ALWAYS a smart idea when messin with electricity to fuse the hot line, shrink wrap, wire loom and even electrical tape the loom as we all know electricity and humidty are not the best of companions. I'm just given you a hard time Nish, but being in the trades I deal with these conditions and equipment daily I would never steer you in the wrong direction.


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## DizzyD (Sep 19, 2006)

find stats for all fans/power source etc. Match #'s appropriately. Purchase a "terminal block" for each power source. Wire fans to terminal block properly. Done deal. A little pricey of a solution, but it's legit and easy.


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## ofblong (Sep 11, 2008)

DizzyD said:


> find stats for all fans/power source etc. Match #'s appropriately. Purchase a "terminal block" for each power source. Wire fans to terminal block properly. Done deal. A little pricey of a solution, but it's legit and easy.


except terminal blocks are harder to make water proof without putting it in an waterproof (I origionally said explosion proof becasue thats what we use at work but it doesnt need to be that type for this application lol) box.


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## jmoose (Jun 21, 2006)

Sorry for bumping old thread but since already nice advice are given here I thought I don't need to set up a new one.

Well I already have a few tanks with computer fans in them for air circulation but this time I want to set up multiple fans with just one power source, so I decide to try a star connection that was suggested here.

But since I am not electronically inclined and don't want burn down my house, I have a few questions for you guys.

I checked barrier blocks on several sites and noticed there are 10, 15 and 20amp for current rating. Which one should I get?
The fan I have says it's 0.09A and 0.96W and I like to connect up to 8 fans for 8 vivs (one each) if possible.

Also like to know what exactly an "inline fuse" is?
What does this do and where it should be connected?
Is there a specific model or type (amp or volt) I should get for my use? 

Lastly can you recommend me a good site I can get them all (barrier blocks, fuse and something else I need to work them right)?

Thank you very much


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## nish07 (Mar 16, 2008)

Someone can feel free to prove me wrong but add up all the amps that the fans are drawing and that will be the ammount of current pulled through the block. Eight of your fans aren't going to pull one amp let alone 10 so that'd work fine. A fuse would want to be just slightly over the ammount of amps being pulled at full load on the fans (I'm sure there's a way to work that out as to which fuse to choose, so that it blows in the event of a short circuit). A 1 amp fuse should work in theory but a 1.5 might be better. Get an electrical guy to confirm. I'd put the fuse between the block and the power source, though.

-Nish

P.S. I don't like the idea of blocks that are open to the air, it's asking for something like a fly or some water droplets to short it out. You could tape them over, I guess. I'm still kind of wodnering if there's something better and yet not too expensive.



jmoose said:


> Sorry for bumping old thread but since already nice advice are given here I thought I don't need to set up a new one.
> 
> Well I already have a few tanks with computer fans in them for air circulation but this time I want to set up multiple fans with just one power source, so I decide to try a star connection that was suggested here.
> 
> ...


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## nish07 (Mar 16, 2008)

By the way, you can get custom length molex connector and molex Y adaptors and branch off of the main line with Y connectors to your fans. It's what I plan on doing. One long molex connector to the first branch where one branch will go towards the first van and the other towards the next viv where another branch will take over. It should work fine for fans. I'm not sure how many would be suited to connect that way but I'm sure it'd be quite a few.

-Nish



nish07 said:


> Someone can feel free to prove me wrong but add up all the amps that the fans are drawing and that will be the ammount of current pulled through the block. Eight of your fans aren't going to pull one amp let alone 10 so that'd work fine. A fuse would want to be just slightly over the ammount of amps being pulled at full load on the fans (I'm sure there's a way to work that out as to which fuse to choose, so that it blows in the event of a short circuit). A 1 amp fuse should work in theory but a 1.5 might be better. Get an electrical guy to confirm. I'd put the fuse between the block and the power source, though.
> 
> -Nish
> 
> P.S. I don't like the idea of blocks that are open to the air, it's asking for something like a fly or some water droplets to short it out. You could tape them over, I guess. I'm still kind of wodnering if there's something better and yet not too expensive.


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## jmoose (Jun 21, 2006)

Thanks for your tips.
When I look for a inline fuse, am I looking at something like one on the bottom of the pic? If so how this can be attached in between an universal adapter and a block?









Also about molex connectors. I googled about it but isn't it more complexed or difficult than using a barrier block? 
Any advantages to go this route, like safety reasons or long lasting ... etc


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## nish07 (Mar 16, 2008)

Either fuse works the same. Whichever is cheapest as long as it's decent quality (read: not gonna fall apart) should work. Don't trust me on which fuse to use, though. Find out from someone who knows better.

About the molex wire, I considered it because the fans I buy have the molex wire and connectors already so it would be simpler to snap them together instead of splicing. I don't know how many fans you can safely string together with molex gauge wire but I'd look into it before running too many.

The block is better than running the fans in series. If one fails the rest will fail. Also, the wiring could get fried if it's too small or the connections aren't good enough. You'll just need to splice the power wire from the adapter to the block and in between add the fuse.

Again, you'll need to look elsewhere for proper fuse and wire gauge.

-Nish



jmoose said:


> Thanks for your tips.
> When I look for a inline fuse, am I looking at something like one on the bottom of the pic? If so how this can be attached in between an universal adapter and a block?
> 
> 
> ...


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## Julio (Oct 8, 2007)

there was a thread abotu the same topic a few months ago and some one posted a ppic of a manifold they created. do a search i am sure you can find it.


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## rmelancon (Apr 5, 2004)

I wire several (actually 8) to a 1500ma 12VDC power brick from Radio Shack. Just make sure the number of fans * ma rating of each fan does not exceed the 1500ma's of the power supply. Max of 1.5 amps can be carried on fairly thin wire with no dangers.

To wire a computer power supply requires a bit more electrical knowledge and soldering etc. There are diagrams to be found on the web if that is the way you want to go but 500W is probably way more power than you need unless you have really big fans or a ton of them.


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## Rich Conley (Jun 12, 2008)

ofblong said:


> watts dont mean anything. You could have a 500w power supply that has 8amps on the 12v rail or you could have a 500w psu that has 40amps on the 12v rail. I thought you were just using a 12v transformer not a PSU. Just add up the amps of the fans. as long as they dont go over the amperage rating on the 12v rail you will be fine. Still be best to daisy chain them like suggested but not all in one huge clump of wires.


8 amps on the 12v rail is still going to run more fans then you know what to do with. Typically, the fans are in the .15 Amp range.


A 12v transformer is going to be much more energy efficient, and cheaper. Typical (less than $150) power supplies run in the 65-75% efficiency range at best, and when we're talking loads of a couple of watts, you're probably below 50%.


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## rikontiki (Jul 15, 2007)

Newegg.com - fan control

you might think about these if you want to control each fan individually or simply have more control over them


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## jmoose (Jun 21, 2006)

Thanks for the tips guys.

I will be getting an universal 1300mA power adopter, so for my 0.08amp fans I can theoretically connect up to 14 fans, right?
My plan is connecting 8 of them but if that's the case I might add more in the future.

Also I will get a barrier block that has enough circuits to accommodate all fans and inline fuse to be attached between a power source and block.
I think I saw a barrier block at HomeDepot but where can I get an inline fuse? An auto repair shop?

As for a fan controller, I remember defaced (whatever happened to him?) suggested it not so long ago and someone was struggling setting up right.
So I think I'd go simpler way since it is for in viv air circulation and adjusting fan speed by changing voltage on adopter.


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## nish07 (Mar 16, 2008)

Unless you can tell me why I shouldn't, I'm planning on using a 5-10 dollar 200 watt computer power supply from newegg. I could theoretically run 22 of your fans on it. The only thing limiting it should be the wire gauge.

-Nish



jmoose said:


> Thanks for the tips guys.
> 
> I will be getting an universal 1300mA power adopter, so for my 0.08amp fans I can theoretically connect up to 14 fans, right?
> My plan is connecting 8 of them but if that's the case I might add more in the future.
> ...


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