[SOLVED] Would it be safe to plug in multiple fan splitters on a fan hub?

[jeffyt]

I just got a new build with the Lian Li LANCOOL II Mesh Performance case. This case comes with a fan hub that has 6 available 4-pin PWM headers. I currently have it maxed out and one of them actually has a 2way splitter - 2x 120mm plugged in. So basically 7 fans to this hub.

I want to add two more fans and was wondering if I could use another splitter, 3 way this time. So take an existing fan out of the fan hub, plug it into a 3way splitter, 2 new fans into the splitter as well and then splitter into the fan hub. So a total of 9 fans on a hub that only has 6 available 4-pin PWM headers.

I've read it's dangerous and might short out the 4pin on the motherboard. The fan hub that came with the case does have a sata power connection but I can not find any info as in model number of the fan hub to actually look up more info.

It seems to have been running fine the last 2 days with 7 fans plugged in... would an extra two fans with another splitter be safe?

Also I am using ML120 and ML140 fans. Seems like google suggests they use around .299 amps each.

Brand new build
MB: X570 AORUS ELITE WIFI
CPU: Ryzen 5600x
RAM: Corsair Vengeance LPX 32GB (2 x 16GB) DDR4 3600MHz
PSU: HX850
OS: Windows 10 20H2 Build 19042.685

 

[Ralston18]

More information needed:

9 fans seems, at least to me, that something is likely astray.

Especially if your system is having temperature problems. If so, report those temperature problems.

If not, then the issue may be moot. No point in adding fans that are not needed.

Update your post to include full system hardware specs and OS information.

Include PSU: make, model, wattage, age, condition.

 

[jeffyt]

Sorry just went ahead and edited it in.

No temp problems. CPU max has been 70 but usually around 60 when gaming and GPU around 71-72. Few hours of Cyberpunk so far.
Silly reason but I am just adding the fans for more color, not temp control. I considered cheaper RGB fans but I am very sensitive to noise and require these ML series fans.

 

[Paperdoc]

What you ask MAY work, but it is impossible to be sure. The limit you're dealing with is the total max load in Amps for all 9 fans. (By the way, your post does not identify them fully, but the facts of saying they provide "more colour" and consume 0.299 A each tells us you have ML120 and ML140 PRO LED Red fans. Similar models without LEDs use less current.) That max load is 2.7 A for 9 such fans.

The limit does NOT affect the mobo headers. The way the fan HUB supplied with that case operates is that all of the fan power comes from the PSU via its connection to a SATA power output, and it does NOT draw any power from the mobo itself. However, the limit is important for the capability of the HUB. Unfortunately, Lian Li does not tell us that. We do know that, because it is fed from a SATA power connector, its limit will be no higher than 4.5 A, and your proposed load does fall under that easily. Whether the construction of the Hub itself allows that full max load to be used is not specified in the case web page. There's a good chance the answer is yes, but no gurantees. You MAY be able to get an answer from Lian Li Tech Support.

 

[jeffyt]

What you ask MAY work, but it is impossible to be sure. The limit you're dealing with is the total max load in Amps for all 9 fans. (By the way, your post does not identify them fully, but the facts of saying they provide "more colour" and consume 0.299 A each tells us you have ML120 and ML140 PRO LED Red fans. Similar models without LEDs use less current.) That max load is 2.7 A for 9 such fans.

The limit does NOT affect the mobo headers. The way the fan HUB supplied with that case operates is that all of the fan power comes from the PSU via its connection to a SATA power output, and it does NOT draw any power from the mobo itself. However, the limit is important for the capability of the HUB. Unfortunately, Lian Li does not tell us that. We do know that, because it is fed from a SATA power connector, its limit will be no higher than 4.5 A, and your proposed load does fall under that easily. Whether the construction of the Hub itself allows that full max load to be used is not specified in the case web page. There's a good chance the answer is yes, but no gurantees. You MAY be able to get an answer from Lian Li Tech Support.

Thank you very much for the detailed response.

I think you are right and I will e-mail Lian Li Tech support but I did find this image in the manual -

It looks like a very basic board that might just be connecting all these things together - like no capacitors or resistors or anything, just an adapter almost... could that be determined by just looking at this or will Lian Li have to confirm? (either way going to e-mail them right after this, just wondering what you think based on this picture)

EDIT: just sent them a Contact Us request through Lian Li main website, thanks.
Also - what do you think would happen if it exceeds the limit? would something most likely fry? like the motherboard, motherboard PWM port, the fan hub? or would it just auto shutdown?

 

[Paperdoc]

You are right, that board is a very simple device. That is all that is required for the job it does. It has two inputs, and six output ports for fan motors. One input cab;e connects to a single mobo fan header, and it does two things. It gets the header's PWM signal and merely distributes that to the Pin #4 of each output so the fans get it. This does not cause any significant load on the header. The other cable plugs into a SATA power output connector from the PSU and that is connected in parallel to all of the power pins (#1 Ground, #2 12VDC) on each output port. Thus all fan power comes from the PSU, and none from the header. In this sytem, there are two potential power load limiting factors. One is the board itself and its metal traces that distribute the power to the port. We don't have any way to know that, unless Lian Li can tell you. The other is that the contacts in the SATA connectors are limited to a max of 4.5 A being fed to the board. If you overload the board with too many fans of high current consumption, the components most likely to suffer damage are the SATA connectors contacts and maybe the board components. It won't damage your mobo header.

As I said above, your plan for 9 fans that each consume at max 0.299 A comes to a load of 2.7 A, and that is no problem for a system limited to 4.5 A.