Power Supply "Fan only" Connectors

[RollingThunder]

These power supply "fan only" molex connectors are 5v, correct?

A novice (which I more or less am with power supplies) assumes "This is where your extra get connected." So you connect a 12v fan to a 5v connector and wonder why it has to be kick started and runs so slow.

How many of us use 5V fans? I can't remember seeing 5v molex connector fans. All the fans I have are 12v. What's the point of these
5v "fan only" connectors? What am I missing?

[meionm]

No they are not. At 5v 120mm fan probably won't run. At 7v most fans will run. I have one connector fan only and it is 12v.

[Oklahoma Wolf]

The fan only connectors are 12v, run from the PSU's internal thermal controller.

[RollingThunder]

The fan only connectors are 12v, run from the PSU's internal thermal controller.

Guys,

Maybe it's me, and it probably is. When I connected 4 pin molex case fans on my Antec TP 480 to the 2 wire "fan only" connectors, they ran slow and had to be kick started. When I changed them to a 4 wire molex, they were fine. The 2 wire "fan only" connector wires are black and yellow which should be 12v but they only show 4.12v with a DMM. My fans are all 12v. Is this a manufacturing error from Antec?

What am I missing?

[T1Cybernetic]

Your best bet would be to check the manufacturer website or manual that came with your power
supply to find out for sure or grab yourself a multimeter and check them yourself just to be 100% sure.

My fan only lead on the antec 430 i have is a 5v but im pretty sure other psu's will very from model to model.

[RollingThunder]

Your best bet would be to check the manufacturer website or manual that came with your power
supply to find out for sure or grab yourself a multimeter and check them yourself just to be 100% sure.

My fan only lead on the antec 430 i have is a 5v but im pretty sure other psu's will very from model to model.

Ok, as I stated the Antec "fan only" on mine appear to be 5v as your TP is but they do check 4.12v with a DMM. I'm ready to drop in a new Corsair HX520 PS and assumed their "fan only" would be the same. I was assured they are 12v so apparently industry standards are not all the same on this.

[Oklahoma Wolf]

The 2 wire "fan only" connector wires are black and yellow which should be 12v but they only show 4.12v with a DMM. My fans are all 12v. Is this a manufacturing error from Antec?

What am I missing?

Those leads are thermally controlled based on the PSU's internal temp - you're finding out just how slow Antec wants the fans to run for silence, and why they love baking capacitors ;)

[RollingThunder]

Those leads are thermally controlled based on the PSU's internal temp - you're finding out just how slow Antec wants the fans to run for silence, and why they love baking capacitors ;)

OW,

Just about the time I think I'm learning about the intricacies of power supplies I find out I'm not!

Both of my Antecs are the same (TP 430 and TP 480). This irks me even more about Antec because essentially you lose two otherwise good connectors. At 5v for "fan only" they are useless. And my assumption this is a standard and would be the same with the Corsair HX520 are apparently unfounded.

[Oklahoma Wolf]

IIRC the Corsairs don't have fan only connectors - I consider that a good thing. Never liked them, because you always have to depend on internal PSU temps to speed up the case fans that way.

[RollingThunder]

IIRC the Corsairs don't have fan only connectors - I consider that a good thing. Never liked them, because you always have to depend on internal PSU temps to speed up the case fans that way.

OW,

They sent me a "fan only" 3 connector adaptor with the HX520 so it's an option. There is no 3 pin MB fan adaptor on it either so am I assuming correctly the PSU will infact detect and adjust fan speeds? From reading Jonny's review that's what I interpreted.

This comp isn't a "power" unit anyhow so I'm not really concerned.

[Oklahoma Wolf]

Most new PSU's have thermal fan controllers inside... only a few of them use those controllers to power outside fans (like Antec via the fan only connectors), and to my knowledge none pay attention to the fan RPM.

It's all based on how hot the PSU is running.

[RollingThunder]

Most new PSU's have thermal fan controllers inside... only a few of them use those controllers to power outside fans (like Antec via the fan only connectors), and to my knowledge none pay attention to the fan RPM.

It's all based on how hot the PSU is running.

My two Antecs have the 3 pin fan connectors for the MB. In all the time I used them both I never saw the PS fan rpms vary (via software reading). They always ran at about 850 rpm regardless of how hot it got and reinforces what you state. Perhaps this is another reason they bake capacitors and is the root of some of the issues I am having with the TP 480 thermal sensor apparently tripping and random reboots.

Hopefully that will change when the Corsair is installed..........

[Oklahoma Wolf]

My two Antecs have the 3 pin fan connectors for the MB.

Yeah - the fans have RPM monitoring, but the monitoring leads connect to nothing at all inside the unit. The fan controller is completely dependant on temperature ;)

They've always run the fans too slow for those Fuhjyyu caps... I only have one CWT made unit here (of four) that has never had problems with those caps. Coincidentally, it's the only one without a thermal fan controller, and runs its fan at full 12v all the time ;)