CLCP fan header power limit

Might want to retest the 1 Amp per header or 4.5 amp total rating Corsair labels the Commander Pro with.

I just had 3 ports die on my commander pro within a day. I was using 3 ML120 LEDs, brand new, which are rated at 0.299mA each. For a Total of 0.897mA draw on a fan header.

All 3 headers died within 24 hours. Not Cool Corsair.

You had all three on a single header?

We've seen issues with triple splitters on a single header. And, technically, Corsair says that splitters aren't supported (though many users, including myself, have 2-way splitters without any issues).

I would suggest that you open a support ticket. And, if/when they RMA your CoPro, limit it to 2 fans on a header.

it could be anything. the point is the same. Their 900mA draw from a corsair fan(s) is too much for a single channel.

If not, lower the spec of the commander pro or up the amp draw of the ML120Pro LED.

it could be anything. the point is the same. Their 900mA draw from a corsair fan(s) is too much for a single channel.

 

If not, lower the spec of the commander pro or up the amp draw of the ML120Pro LED.

Look dude ... I can only reiterate the official specs and what I've seen from experience here on the forum. The official specs, from Corsair, are what they are. Many users have seen issues with 3-way splitters. Many users, including myself, have had success with 2-way splitters for long periods. You'll see this repeated all over the forum. Regardless of the specs, regardless of the power draw, I don't recommend that folks use 3-way splitters.

I've suggested that you open a support ticket to try to get an RMA and to limit them to 2-way splitters. You can either take the advice or not ... totally up to you, dude. It doesn't hurt my feelings one way or another. But arguing about the official specs isn't going to change anything. And, for the record, since Corsair doesn't officially support using splitters with the CoPro at all, arguing about the current rating is somewhat moot.

0.299mA multiplied by three isn't what you're doing, an increase in wiring length and each additional connector significantly impacts the current drawn.

Not to butt in, but I don't think I agree with that. Granted its light gauge wire (#24 according to DevBikder's post here)

http://forum.corsair.com/v3/showthread.php?t=174759,

but at the lengths encountered inside a computer case, even with a fan extension cable and extra set of connectors, the amount of power dissipated by the wire and the connectors should be trivial compared to the fan load, unless you have some very poor crimps.

The OP said max current draw for ML120 Pro is 0.229ma. Actually, according to the Corsair site, the max current is 0.225 Amps (not milliamps) which is 225 milliamps.

https://www.corsair.com/us/en/LED-Color/Fan-Size/Package-Quantity/ml-pro-config/p/CO-9050040-WW

A quick Google reveals that 24 AWG wire has a typical resistance of about 25.67 ohms per 1000 feet. So even if the fan cable is 10 feet long, the resistance is ~0.25Ω. Since the ML120 draws 0.225A max @12VDC, Ohms law tells us that the resistance of the fan is about 53Ω. Power consumed by the fan is ~2.7 watts. Power consumed by the wire is ~.013 watts.

As for the connectors, the pins are Molex 16-02-0114 (per DevBiker's same post). These contacts have a rated contact resistance of 10 milli-ohms (.01Ω) which is way lower than the wire, so unless there is a bad crimp, the Molex pins are not adding any significant resistance to the circuit.

So, ignoring the wire and connector pins, 0.225 A x 3 fans is 0.675A, which is still far below the Co-Pro spec of 1A per fan header. That said, since a triple splitter does not seem to work, perhaps it is not a current limitation. Maybe something to do with PWM data from 3 fans being tied together? Often when using a fan splitter with PWM fans, the PWM line is lifted to all but one fan on the splitter. I may be totally off base but have you tried that?

The connectors in my post are for the RGB connectors, not the fan connectors. But still ... your points here related to the resistance and calculations are dead on. Nice explanation!

I'm not sure that it has to do with a PWM line. I've yet to come across anyone that has said that they've successfully run 3-way splitters on the CoPro. Honestly, I don't know what the root cause of the issue is ... I just know that this has been a pretty consistent issue. So ... it's kinda like "don't do that, it hurts." "Why does it hurt?" "Doesn't matter ... just don't do it. Because it hurts."

Interestingly, we have similar issues with some of the Noctua fans as well.

Not to butt in, but I don't think I agree with that. Granted its light gauge wire (#24 according to DevBikder's post here)

 

http://forum.corsair.com/v3/showthread.php?t=174759,

 

but at the lengths encountered inside a computer case, even with a fan extension cable and extra set of connectors, the amount of power dissipated by the wire and the connectors should be trivial compared to the fan load, unless you have some very poor crimps.

 

The OP said max current draw for ML120 Pro is 0.229ma. Actually, according to the Corsair site, the max current is 0.225 Amps (not milliamps) which is 225 milliamps.

 

https://www.corsair.com/us/en/LED-Color/Fan-Size/Package-Quantity/ml-pro-config/p/CO-9050040-WW

 

A quick Google reveals that 24 AWG wire has a typical resistance of about 25.67 ohms per 1000 feet. So even if the fan cable is 10 feet long, the resistance is ~0.25Ω. Since the ML120 draws 0.225A max @12VDC, Ohms law tells us that the resistance of the fan is about 53Ω. Power consumed by the fan is ~2.7 watts. Power consumed by the wire is ~.013 watts.

 

As for the connectors, the pins are Molex 16-02-0114 (per DevBiker's same post). These contacts have a rated contact resistance of 10 milli-ohms (.01Ω) which is way lower than the wire, so unless there is a bad crimp, the Molex pins are not adding any significant resistance to the circuit.

 

So, ignoring the wire and connector pins, 0.225 A x 3 fans is 0.675A, which is still far below the Co-Pro spec of 1A per fan header. That said, since a triple splitter does not seem to work, perhaps it is not a current limitation. Maybe something to do with PWM data from 3 fans being tied together? Often when using a fan splitter with PWM fans, the PWM line is lifted to all but one fan on the splitter. I may be totally off base but have you tried that?

real world is a different matter. I used to run splitters for HDDs, with splitters I was limited to 10 HDDs off a certain PSU, without splitters (custom wiring with vampire crimped connectors) I managed 24 HDDs before running into current draw issues (the initial spin up when the most current is drawn, just like fans). This initial burst is what would be smoking the mosfets.

I did consider that splitting the 5v PWM signal could also be the issue, but motherboard headers can run 5-8 way PWM splitters just fine off a single header. Arctics daisy chain system for fans is also rated to 5 fans off a single PWM signal.

issues with the PWM signal from a splitter, I can understand.

This is the 12Volt power.

Also, Who is wrong:

Corsairs Website which list the amp draw of .229 or the Fan label on all 9 fans I have?

Picture of the fan amp draw.

https://imgur.com/a/5rpMOKB

Its been a week, and i am still waiting for an RMA # to send this thing in. :/

real world is a different matter. I used to run splitters for HDDs, with splitters I was limited to 10 HDDs off a certain PSU, without splitters (custom wiring with vampire crimped connectors) I managed 24 HDDs before running into current draw issues (the initial spin up when the most current is drawn, just like fans). This initial burst is what would be smoking the mosfets.

 

I did consider that splitting the 5v PWM signal could also be the issue, but motherboard headers can run 5-8 way PWM splitters just fine off a single header. Arctics daisy chain system for fans is also rated to 5 fans off a single PWM signal.

That is interesting that having splitter connectors in the line reduced the maximum number of HDDs off the supply from 24 to 10. I have to say I am surprised that there would be that much loss, if the pins are crimped and mated properly. Perhaps you are right...

issues with the PWM signal from a splitter, I can understand.

 

This is the 12Volt power.

 

Also, Who is wrong:

Corsairs Website which list the amp draw of .229 or the Fan label on all 9 fans I have?

Picture of the fan amp draw.

https://imgur.com/a/5rpMOKB

 

Its been a week, and i am still waiting for an RMA # to send this thing in. :/

The Corsair website says ML120 Pro drawing 0.225 amps (225ma). Your fans in the photo say 0.299 Amps (229ma). Yes they are 2 different numbers, which is not strictly correct, but the 2 stated values are only 0.004 Amps (4ma) apart, which is not very much.

The resistance of the wire is negligible. If 1 fan draws 0.229A with 12VDC across it, the resistance of the fan is ~52.4Ω. 3 fans in parallel would be ~17.5Ω. At 12VDC, the total current should be 0.687A.

12V / 17.47Ω = 0.687A [OR]

3 Fans x 0.229A = 0.687A

So Ohm's law says the port should drive 3 fans no problem. If you use 0.225A instead of 0.229A, the total current is 0.675A which is a total difference of 0.012A, which is 3 x the 0.004A per fan difference stated above.

So, after all of this, why don't 3 fans work on 1 fan port? I don't think it's a current issue. Have you tried lifting the PWM wire from 2 of the fans? That is the only thing I can think of that would cause a problem. It is true that certain other brands of fans have had problems being controlled by a Co-Pro. I did some Googling about this awhile back and there are differing methods of PWM control, so I thought it must be that. But I have never heard of these types of problems with various brands of fans being plugged into any motherboard with PWM fan headers. They seem to work fine with whatever brand and model of fan gets plugged in. I don't know why the Co-Pro fan ports seem to be so picky. The issues could be related.

All I can suggest is to try lifting 2 of the fan's PWM wires and see if they start working properly. If you have tried that, I am out of ideas and defer to DevBiker. It should work, but it doesn't, so don't do it. Lame, I know :[pouts:

so after 7 days from the time i submitted my ticket. I finally got an RMA. I printed the slip and went to ship it out, and theres no address. WTF.

I call Corsair, and they said that there was no need to send in my unit, since a replacement is being sent out to me today.

finally, hopefully there was a 'lot' issue with some of the units.

Also the problem is NOT PWM. The Ports die due to current draw.

There is no longer a 12V supply on the fan ports.

Funny. I tired one of my Noctua Industries 3k 140mm fans that pulls 0.6amps on one of the remaining headers. Guess what, it died after less than a day. Chalk it up to a bad unit. Hopeful the new one is improved.

Yet ... I have multiple headers with 2x LL and 2x HD fans, which together draw .60A. No issues.

There's definitely something amiss here. I just wish I knew the root cause.

Please post how it goes with the replacement Co-Pro. If I were you, I wouldn't put more than 2 fans on a port. People had problems with Noctuas right when the Co-Pro was released. IIRC, they were one of the reasons Corsair added the ability to manually select the fan type. I don't know if that resolved the issues with Noctua fans. Corsair (rightfully IMHO) said they could not guarantee proper operation with 3rd party fans. Fair enough I guess but I still don't get why it is so finicky when even cheap MOBO PWM headers will drive pretty much anything.

If you have a VTVM with DC current measurement capability, you could take some current measurements. You have to put the meter leads in series with the 12VDC which is a bit of work. I would say the Co-Pro is really limited to 600ma per port but then why can DevBiker connect 2x LL or 2x HD fans and not have a problem? Hmmm...:thinking: