Fan Q

[catarrhine]

Hi, I have a question I was hoping someone could help me with. I currently have an Enermax Noistaker 600w (v.2.0) as my power supply and I have four fans in my case; three papst 120mm 4412 F2GM fans and one 80mm Adda fan that came stock with the Lian-Li PC6070 case. My setup is as follows: One 120mm fan as intake, two 120mm fans on an internally mounted radiator, and the 80mm fan mounted to exaust out the back of the case.

I was leak testing (for my WC setup) last night with the Innovatek HPPS pump plugged into a 4-pin molex. Everything ran as it should. As my rad and fans are mounted, I decided to test them as well for fun. Each fan's 3-pin connector is plugged into a 3-to-4 pin 12v-7v adaptor. The adaptor is meant to draw power from the PSU via 4-pin molex connectors.

If I plug in one fan, the PSU can power up and run both the pump and the (now) 7v fan. Example:

PSU molex-->female fan adaptor molex-->wires of the adaptor-->male fan adaptor molex-->Female molex extension-->pump

I am not sure of the terminology, but I would say that I have connected the fan "in series" with the pump. The addition of the second fan to the series results in the PSU not powering up. As an example:

PSU molex-->Fan #1-->Fan #2-->pump.

Note that all three items (both fans and the pump) are deriving power from a single molex connector from the PSU. I take it that this is bad, and that not enough juice is mustered up to power all three items from the single molex. I understand that I will probably have to connect each fan to a separate molex connection from the PSU.

But one thing plagues me: the 12-7v adaptors have both a male and female end, suggesting that something should be plugged in to both ends. Plugging in a 4-pin molex from the PSU solves half of the problem, but what of the other end; the male one? Does it have to be plugged into a female molex that is, in turn, connected to a power-drawing component in order to complete the circuit? Or can it just sit there?

Okay, here is the fan adapter:

Here is a pic of the PSU 4-pin powering the pump (nothing special, I guess, but may be useful).

And here is a pic of the 2 radiator fans plugged in to the adapters. The adapters are plugged into each other.

Now, if I take the adapters (plugged into each other) and place them before the pump, the pump will be getting 7v instead of 12? If so, that makes sense. Here is what I mean:

Now here is a different fan question that is not water pump related. The green arrow in the third picture above is pointing to a male molex that has nothing to plug into. Drawing:

If the power supply is switched on, it will not power both of the 120mm fans. Is that because the male molex needs to be plugged into something that draws power? Or is it just too much draw on the PSU to power up both fans off of the same molex connector? I have the feeling the answer is pretty simple, but for the life of me, I need help.

The PSU will start, at most, One 120mm fan and one 80mm fan. Two 120mm fans cannot be started; the PSU powers up for a second, the fans barely begin to spin, then, everything stops. This forces me to turn the PSU on and off a few times and wait before I attempt again. This happens no matter how the two 120mm fans are attached, whether in series or on separate lines on separate molex connections. In all cases, there is an unconnected molex hanging from the fan adapters. To clarify, the PSU will spin a 120mm and an 80mm fan, even with the hanging molex unconnected.

Also, I don't know how much difference it will make but I am running the PSU outside the case and not hooked up to the motherboard (I have jumpered the connectors).

 

[JTY]

That last molex connector doesn't need to be connected to anything.

As for power draw, I'd try pluging the pump into it's own lead from the PSU. However, that may not solve the problem.

What all are you running in that machine? You may be reaching the power output limit of one of the PSUs rails, or the whole PSU.

 

[catarrhine]

Thanks a bunch for the input. At the moment, the only things I am running in the machine are the pump and the fans. I used the bypass trick to be able to run the PSU without hooking it up to the mobo. So I guess only one rail is being used, even though I am using multiple strands of wires from the PSU.

Thanks for clarifying that the last molex connector need not be plugged into anything.

I tried to plug the pump into its own lead from a strand separate from the fan strand and everything worked okay:

However, when I add a second 120mm fan to the PSU, even on an independent strand, it does not work:

So that is where things are. Would it help to connect the ATX to the mobo? I am really at a loss here. The PSU is rated at 17amps for 12v rail #1 and 18amps for 12v rail #2.

Here is the configuration of the system:

Enermax Noistaker 600W version2 PSU

Mobo Components:
Athlon FX 53
ASUS A8V rev.2
Ballistix PC4000
GeForce 6800 GT
Lite-On DVD ROM

Non-Mobo components:
74GB Raptor
Three (3) Papst 4412 F/2GM 120mm fans (One as intake, two on radiator)
One (1) Adda 80mm fan
Innovatek HPPS 12v pump

I also have a rheostat that I want to use for one of the 120mm fans on the radiator. This would connect into the three-pin header on the mobo and, assuming everything was okay, could possibly eliminate one 120mm fan from being powered directly from the PSU. But even then, it still does not solve the problem of getting that last 120mm fan to power up (at 7 volts). I am not sure where to go from here?