Help with XD5 Pump leak testing, power issues

[Corpskil]

Hello! I'm in the process of leak testing my first ever Custom loop! It has been tons of fun building and I'm finally at the leak test stage when I noticed some strange activity in the pump and would like to understand it further. AS stated in the manual, I've got the psu plugged only into the molex 4 pin connector to pump. The system primes full no problem, but during the 24 hour leak test I notice the pump is running dead slow, like a trickle out of one fitting where a bubble has formed and its measurable (I have no flow indicator in my loop). Then I started doing some digging.... and this is what I found.

 

1. when disconnect my psu from case the pump kicks up in speed, as in, when I remove the mount screws, but not full power as the dead still bubble starts to move a little more then it was. (grounding through chassis??)

 

2. when I disconnect the fan control (from commander pro channel 6) with psu removed the pump kicks into full gear 100% (just a guess as I finally seen the bubbles whip through the loops like I figured they would)

 

3. PSU mounted to chassis but fan control removed, still high speed.

 

So unless I'm missing something, it seems one of the connections on my commander pro is grounding to the case somehow?? or does the fan control also need to be unplugged when leak testing as the commander pro limits the flow?

 

and help would be much appreciated thanks

[Zotty]

while filling you should only have the pumps molex plugged in buddy., the commander pro is most likely controlling the pumps speed as its most likely running in hardware mode.

[Corpskil]

Thats what I figured, as stated it says ONLY have molex plugged in, but I figured that statement was isolated to the PSU and its cables as I have the whole system wired up and ready to go once leak testing is done.

 

Thanks for the clarification. I havent had the computer on to test anything software related for the pump as I'm still in this stage.

 

Cheers!

[c-attack]

If the pump PWM connector is set to coolant temp from one of it's thermistors, it will still run it's curve (or last known speed if without) when the PWM plug is connected. Once you remove it, the pump reverts to full speed and will stay at full speed even if you reconnect. This is typical of all D5 pumps and most other types as well. It will resume normal operation the next time you load up.

 

In big cases with large loops you probably want max pump speed on fill. However, in smaller systems or 1 block/1 radiator systems that could easily be too fast and you get to have a panic moment lunging for the PSU switch as the reservoir empties in 0.5 seconds. If you know what you are about to do, you can always set a fixed PWM % in the Commander to lock the pump at an ideal fill speed.

[Corpskil]

yeah this answers my question, I figured it was being controlled by the commander pro, just want to double check, thanks for the tips!