|NZXT Sentry Mix Fan Controller|
|Reviews - Featured Reviews: Accessories|
|Written by Marc Fruchtman|
|Wednesday, 31 August 2011|
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Closer Look: Interior Features
Here we come to the internals of the NZXT Sentry Mix. It comes with six 3 pin fan connectors. And 2 Molex connectors that are spliced into a 3 pin power connector that will be used to connect to the main PCB. On the first pass the overall build quality is good, but please see my many comments below for more detail. All the connectors fit snugly and without difficulty, with the exception that channel 1 is positioned such that removing the connector once it is on, is not so easy. This could be alleviated if the connector on the PCB had been rotated 180 degrees. The included cables are nicely tucked away, but can extend to approximately 28.5 inches.
Here we have a perspective view of NZXT's Sentry Mix Fan Controller. It has standard external drive mounting positions. There is not much to see on the outside looking in, so we move to the detailed interior features.
Here we have the PCB, currently in revision 4.0, though it might be difficult to see from this image. Many of the components are unmarked as this is a pre-release sample. Some of the capacitors are labeled “Qunlo”, some are labeled “china” and for some I could not find any identifiable markings.
Overall, the layout is pretty good. As mentioned, the one area that was problematic was connector for channel 1, because it is rotated such that the latch is right against the mounting screw for the board, making it difficult to remove if you wanted to remove the wiring.
Here is the switch for the LED colors. If the switch was just a little less recessed it would be do just fine.
The Sentry Mix is designed for 50 watts per channel. If an end-user were to ever actually use the full rating of the fan controller, that would be 300 watts. However, if you visit the site for Molex, and check out the spec for the maximum Ampacity of a Molex connector, you will find that it is rated for only 10 amps or if you visit your wiki, you can see Molex 8981 Series is rated at 11 amps per pin. It's somewhat confusing that such a ubiquitous connector has so many disparate values for ampacity. Nevertheless, the interesting thing is that basically, a Molex connector is limited to somewhere around 10 to 11 amps.
The formula for Power (watts) = I * V where power is watts, and I = amps, and V = voltage. So, a little math shows us that 300 Watts = I amps * 12 volts (the operating voltage of the controller).
We solve for I, and get 25 amps. Perhaps, there is something missing here, (and I will be more than glad to change these calculations if someone can provide reasonable proof of error), but it appears that the 2 Molex connectors are under sized for the maximum rating of the controller by about 3 to 5 amps (depending on who you believe, Molex or the Wiki).
Finally, the wire used to splice the Molex connector into the 3 pin connector was 16 AWG. According to the Handbook of Electronic Tables and Formulas for American Wire Gauge, the maximum is 22 amps for 16 gauge hookup wire. So, again, it appears the wiring is just slightly under sized for the maximum continuous rating of 50 watts per channel. We have forwarded this concern to NZXT and we are waiting on the final response.