Fan Chaining

[Sam]

Quick Guide on how to Chain fans together to reduce the number of cables and headers used, very useful for those with either lots of case fans, or a water cooling set up :thumbup1:

Firstly sort out the position of where you want your fans to go, and where you want the cables to dissapear off to, you'll need a common link point from the fans going to a header / psu cable, so bear this in mind when planning the cabling, you can get some impressive distances from the header to the fan this way.

When daisy chaining fans, the best results are achieved by running the fans in parralel to minimise voltage drop accross the fans, to do this, you'll need to connect the cables up with like colours, so red to red, black to black. The yellow cable needs to only come from one fan to avoid causing a short, as this is the fans speed sensing line, transmitting to the unit reading them.

Tools Required

Side cutters
Cable Strippers
Soldering Iron
Solder
Heat Shrink

I'm going to use the example of wiring up 3 fans on a tripple radiator as the basis for this guide, but it is easily adaptable for any circumstance.

The first thing to consider is how many fans you are going to be linking together, and the rated output current of the unit supplying them, most headers have a maximum current of 1 Amp, and most fans have a current draw of 0.2 Amps, so 4 fans is the maximum I would reccomend anyone to put together, as when fans first start up they draw more than their rated current briefly. As 3 fans are being used, we're ok.

Cut the plugs from 2 of the fans near the plug end of the cable, and cut the last plug off near the fan side of the cable, leaving enough length on the cable still on the fan to be able to strip back and solder it to the other wires. This shorter cable is to be the "Hub" for the set up. On the radiator itself. Attach the fans so that the fan with the shortest cable is nearest the header, to reduce any excess cable and make things that much neater. Next place the remaining two fans onto the radiator so that all three have their wires on the same side.

With the fans in place, take the long wires and get a measurement for how long they need to be to reach the Hub. Cut them down to suit and strip back roughly 10 - 15mm of insulation, depending on how good you are at soldering, additionaly, remove as much of the yellow wire as possible from the two of the fans, making sure to leave the one on the hub fan in place. Once stripped back, check once again that the cables will reach and tuck away nicely down the side of the fans. Next, strip back the wires on the cable with the connector still attached. Prepare any braiding you may require, as its easiest to apply at this stage, You'll need to cut lengths for each wire, as the join will make it very difficult to braid, however it may be possible to use one length of braid, feeding the wires through gaps cut into it, having never used braiding before, I cannot say for certain.

Cut three lengths of heat shrink, roughly 40 - 50mm long, depending on how much insulation you have stripped back from each wire and slide these over the wires still attached to the plug. Twist the ends of each wire to keep the individual strands together, then tin them with solder by applying a small ammount of solder to the end of the iron, then hold both the iron and the solder onto the cable from oppisite sides, as the solder starts to flow onto the wire, draw the iron and the solder towards the end. This should leave you with an ideal finish for joining the wires later.

Once all of the ends have been tinned, you'll need to join all the red wires, all of the black wires, and then the two yellow wires, the one attached to the plug, and the one still on the hub fan. Do this by twisting all of the ends together, to give the best joint have the fan wires coming in together, then the wire from the plug coming in from the other way, so that it appears the three fan wires are forming into one and continuing along the cable. With the wires twisted together, solder them together in a similar manner to how you tinned them, apply a little bit of solder on the end of the iron, then apply the iron and the solder to the wires from different sides. As you already have a decent ammount of solder on the wires, you will not require a great deal more, just make sure to get it all flowing nicely, but try not to get the wires too hot, so be as quick as you can with the iron. It may help to have anothe pair of hands for this part to hold the wires whilst you solder, as they can have a tendency to move.

With all of the wires soldered correctly, red to red, black to black, yellow to yellow, allow it to cool breifly then slide down the heat shrink to cover the soldered joint. Shrink it over the joint with something hot, preferably a lighter or a hair dryer, just avoid using the soldering iron as the heat from it is too concentrated to shrink the wrap effectively, and may burn it.

Once complete you're ready to go! plug it in to a header and test the fans operation before installing into the water loop.