Lamptron Fc5 v3 Fan Controller PROBLEM

Prochaos · 24 Jul 2015 at 11:18

So ive had this fan controller hooked up to 9 noctua industrial ppc fans since last September and i love it ascetically however i cant have the rpm below 1080 or the fans will just go off next time i turn on my pc or go off if i bring it below 800 while the pc is on, this issue has always been there but the noise of the fans from 1090 - 1200 rpm hasnt bothered me too much however with the new 750d front panel with ventilation holes the noise is a little higher and unnecessary if the case will be the same temperature with the fans at 1200 or 800 rpm which is what id like them to be at, nice and silent.

Is there a solution to this problem ? like an adapter i can attach to them to reduce the voltage ?

if i had been smart at the beginning i would have just connected them all to the psu with a and a cable connected to the mobo to control them, but id like to still use the fan controller if possible for the internal temperature sensors.

Tealc · 24 Jul 2015 at 13:09

I reckon a 3000RPM fan won't go much lower than 1000RPM and have enough power to actually start up. Fans are able to run at a lower voltage provided they have a higher voltage kick for a short duration to get them going. Once inertia is overcome they will often run quite low. A fan controller tha starts all fans at 12v and then brings them down to idle voltage would be the ideal solution, or a modification to the existing controller somehow.

Maybe try using some fans that aren't stupid fast like 3000RPM. Do you really need that amount of airflow?

Prochaos · 24 Jul 2015 at 14:23

Sorry i forgot to mention which fans im using, the following
7 x Noctua NF-F12 IndustrialPPC 2000RPM IP67 PWM 120mm
3 x Noctua NF-F12 IndustrialPPC 2000RPM IP67 PWM 140mm

Tealc · 24 Jul 2015 at 14:30

Ah they are the 2000rpm versions.

Pwm fans are sometimes tricky to slow down using voltage control (I assume your fan controller is not a PWM based device). The onboard electronics won't have such a tolerance for low voltage as they are meant to have 12v at all times.

Not much to suggest I'm afraid.

Tealc · 24 Jul 2015 at 16:21

...although you might see better results with driving them by PWM. Depends on the fan spec. The stated minimum may be higher than you are already achieving.

ttaskmaster · 24 Jul 2015 at 16:47

I'd offer to swap, but I have 9 non-PWM Noctuas running off the very same controller!

Prochaos · 24 Jul 2015 at 21:03

ttaskmaster said:
I'd offer to swap, but I have 9 non-PWM Noctuas running off the very same controller!

Do you have the same problem taskmaster ? I thought it was faulty at first but it took so much effort to wire it all in I've just left it be, but I'd much prefer if it were silent considering Ip the temperature difference from 800 rpm and 1140 rpm will be negligible

ttaskmaster · 27 Jul 2015 at 15:15

Prochaos said:
Do you have the same problem taskmaster ? I thought it was faulty at first but it took so much effort to wire it all in I've just left it be, but I'd much prefer if it were silent considering Ip the temperature difference from 800 rpm and 1140 rpm will be negligible

Ah, hang on - Just checked my facts.
I have the FC6.
It was teh FC5 V3 that I was going to get!!

However, they should basically work the same...

First thing to remember is that you have 30W per channel. You need to add up the wattage of all the fans you have plugged into each header on the FC5. If they're more than 30 (personally I'd try to stay below 25) then you may need fewer fans on each channel. This is usually just a case of adding in enough splitters/Y-Cables... I assume the Industrials come with teh usuall array of Noctua accessories?

I personally like to divide fans up between the channels according to their function.
So for example - Ch1 controls the two front intakes, Ch2 is the three internal airflow relays, Ch3 is the two side intakes, Ch4 is the two top exhausts, Ch5 is the rear exhaust... and you've a 6th channel if you need it.

Secondly - I find the Molex connector on these things can be a little loose. Check both the socket on the FC5 and the connecting cable between that and your PSU cable. Might just need the pins pushing in tight with a small flathead screwdriver.
This is why I hate Molex connectors!

Thirdly, I don't have a voltage display on mine but most of my fans only need enough power to spin them up from about 350rpm. If I turn the dials below that and then restart, they won't spin up.
I'm reckoning the Industrials need more, since they seem designed to spin rilly rilly fast!
I've had PWM fans before and they worked just as well, though.

If the Industrials don't need a high starting voltage, then I'm guessing you either have a slightly loose connection, or there's an actual problem with your FC5.
Just my guess, though - I'm not a particular expert, or anything!

Tealc · 27 Jul 2015 at 16:18

Seems the industrial PPC start around 5v and 800rpm (not sure how they measured the rotational speed) which isn't that bad for a fast spinner and isn't that far away from what you are seeing.

The blurb says they will run at 450rpm given a low enough PWM duty cycle. So my recommendation would be to PWM control your fans, hopefully the fans don't tick like some do under PWM.