DIY Power and USB Supply for external Radiator

Throughout the last summer, the temperature of my PC was mostly above its comfort temperature, so I have now replaced the parts of the internal water cooling with an external radiator (MO-RA 3¹), which should no longer have any problems dissipating the heat.

Situation

The radiator is located under the desk in 2m distance to the PC and requires both a power and USB connection to it, so that the pump and fan can be controlled.

In the german hardwareluxx forum² there is a long thread about the MO-RA3 and also various good implementations of such a connection.

I have finally decided on the following solution and would like to call with this post to their reproduction.

In the end, the radiator should be supplied with both power (5 and 12V) and USB with a single cable. An Aquacomputer Quadro³ is installed under the MO-RA fan grill, which controls a Laing DDC-1T/Plus PWM pump and 4 Noctua NF-A20⁴ fans.

Cable and Socket

I chose a Neutrik XLR plug-in solution because it has already proven itself in other projects and will probably last longer than the PC and all the cooling equipment.

Neutrik offers various plugs and sockets, 5 pins are needed for the cable (5V, 12V, GND, S+, S-), so the matching parts (available in both silver and black) are:

• NC5 MXX⁵
• NC5 FD-L-B-1⁶

The search for a suitable cable turned out to be a bit more difficult, since the Neutrik connectors allow 1.0mm2 wiresize, but there are hardly any suitable power / signal cables. Here I ended up with the Tasker TSK1048⁷ cable, which is ideal with 3x 0.75mm2 and 2x 0.22mm2 (separately shielded) at 9mm OD. To fit the cable to the connectors, the large bushing BXX-14⁸ is needed.

To spruce up the cable a bit more, a sleeve like the MDPC-X Medium Sleeve⁹ fits ideally under the end sleeve (I used titanium grey), see pictures below.

The pinout of the cable can be freely selected, I picked the one shown below, which I also used for other systems so the components can be exchanged now arbitrarily among those. I recommend to ground the shielding of the cable on one side.

Internal cable routing

The power supply is done via a Molex housing in the PC, from which 5V, 12V and once GND is used. From the USB connector only the two signal wires S+ (green) and S- (white) are used, all other wires are not connected.

In order to simplify things, you can use one of the connection cables (Aquacomputer Product Number 53215) for USB and split it.

For the Mora a 90° Molex connector is needed, also the mini connector of the Quadro. Here you have to supply both the USB and the power connector of the Quadro with 5V and GND each, and of course the two signal lines for USB. 12V is only necessary for the Molex connector of the Quadro.

Furthermore, the socket should definitely be grounded to avoid unpleasant surprises.

Footnotes