pump speed not contollable by mb header

fastboy

fastboy

fastboy

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ok bit of a weird one and maybe im just missing something.

gigabyte z87 hd3 board.
has x4 4pin fan headers.

i can control both my cpu fan speeds and aio pump and rad fan speeds via the gigabyte software np..however im going full custom WC and just got myself an ek dcp 4.0 off ebay http://www.ebay.co.uk/itm/201395526727?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

pump just has a single 3 wire plug like a fan.

..now im confused because the pump will only work if connected to the cpu header or molex via adaptor,it wont work if connected to sys fan 1,2 or 3.

in cpu header i cannot control pump speed it just goes flat out,even tho if i unplug pump and plug cpu fan in cpu fan header i can control the fan speed..so the software must be working?

any ideas??

ta
dave
 
Last edited:
In order to control the pump speed via the CPU_FAN header, you need a 4-pin PWM connector - Your pump has a 3-pin, according to EK's website, which means you have voltage control only.
It also draws 18W, which may be too much for the other headers - These usually power one or two fans, which are often less than 1W draw each!

So... I'm *guessing* that, with only 3 pins, it needs all 18W to run the pump and so reducing the voltage as if it were a fan would stop the pump from working outright. The only option is to run it full speed.

I'm no expert, especially on PWM. However, I'd just power the pump from the molex, control the radiator fans PWM off the CPU_FAN and let those adjust according to whatever temperatures you set the curve to in your software.
Might be a bit noisy if the pump is on full tilt, though...


I may well be wrong and there is a way to achieve this, but that's how it's looking to me.
 
yes the pump is noisy flat out :)

i will get myself a voltage regulator then and/or make a molex up to drop the voltage.

thanks
 
You could get a buck converter from ebay for a few quid and put it between your Molex and the pump. You'll have to adjust manually though or set and forget at a happy medium. I suppose ideally you could interface PWM onto a buck converter and have it output proportionate pump speed. I'm not sure if there's anything to do that besides a DIY solution.

Some fan controllers will allow regulation of a pump.
 
Tealc said:
Some fan controllers will allow regulation of a pump.
Click to expand...
Those that allow 'up to 20w per channel' or more, I assume?
Am I correct in reckoning pumps won't run with less than the stated wattage, in this case 18w?

Asking because I was contemplating putting my own pump on FanCon and rad fans on CPU_FAN, myself...
 
i got myself one of those chinese 3 amp pwm motor controllers off ebay for a fiver delivered the other week (for my 6 fans on the radiator) and thought i would give it a try on the pump,seems to work just fine and i can now turn the pump down to about 7 volts before it stops,much quieter now so theres a viable option that way i guess?

i cut an old molex up and ran it off the psu and seems fine...touch wood :)
 
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