Custom Cable Question

Hoping some peeps have sleeved their own cables here. Got a couple quick questions.

My Seasonic has a few double wire single connector runs, using a 22AWG and 18AWG, unfortunately a couple of these broke during extraction. If I use a dual 18AWG from a different connector, would this cause any issues? I doubt it, but just wanted to verify as I'm not too versed on electrical aspects.

Would it cause any problems if some cables are of different lengths on the same connector? such as having 2 of the 24 cables on the 24 pin being around 50mm or so longer? so 22 being 600mm, and 2 being 650mm.

Any info would be greatly appreciated.

Usually when there's two wires going into the same pin, and one of them is smaller, that smaller wire is a voltage sense circuit to allow for finer control of the voltage. Using wire from another connector won't work in that case.

As for longer wires, it shouldn't be too much of a problem, but you'd need to make sure that they're sourced from the same rail if you're using a multi-rail PSU.

Damn. I mapped out all the connectors and know exactly where every cables go. Even the ones of different gauges. So the cables will be routing the same exact way the manufacturer had them.

In terms of the smaller cable, so using a double wired cable from the pci-e connector that is dual 18awg ,and placing it in the 24 pin connector replacing the dual 22/18 awg, following the same manufacturer diagram and layout won't work? Damn, that throws a wrench into my plans. Going to have to buy new ends and remake the cables if that's the case.

Also I take it you meant to say "shouldn't"? =P. Rail wise though, single 12 volt rail on my psu. But also considering I mapped where every cable goes from the psu, I think it should be a non issue.

If everything goes to the right place, 18/22 awg won't be any different from 18/18. You will just be using an extra thick wire for something that won't carry that much current.

Thanks Tsumi. I was thinking the same thing, can anyone else confirm this as well for me? Last thing I want to do is to get it up and running and end up blowing something in my new rig.

He's correct. 18awg in place of a 22awg will not affect anything. However, (as he also said) that's only if everything is going to the right place. Are you splicing an 18/18 wire pair that you cut from another connector onto the existing 18/22 pair? Or are you just relocating that 18/18 pair from one bundle to take the place of the entire 18/22 pair in another bundle? If the former, that'll be fine. If the latter, then you may be losing a sense function that the 22 awg might be serving because it would go to a different spot inside the PSU. How the PSU will behave without that sense wire is unknown, it could just not work at all, or it could overvolt that rail. It could also not do anything different than it normally would.

Here's an example of what I mean. This is one of the +3.3v wires that goes to the ATX 24pin connector. The PSU uses the feedback from the smaller orange wire to boost the voltage of the +3.3v line to keep it at +3.3v at the motherboard when the load on that rail goes up.

You're last post through me off a bit Ryan. I think we might be thinking of different scenarios. I'll try to explain it in a bit more detail to make sure we are on the same picture. My PSU internals also have very little cabling internally, as most are soldered from one pcb to another on the bottom. Internals pictured here.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=264

But in terms of what I'm doing. I'm not splicing an 18/18 onto an exisiting 18/22 pair of cable. Not extending the cable what so ever, and not turning it into a 4 wire cable. Basically, the cable that I was extracting, an 18/22 gauge cable, broke off from the connector. It was connected to the 24 pin connector, that would run off and connect to two separate points on a 10 pin modular connector that would go into the PSU. So I'm replacing that cable in it's entirety, with a cable I pulled from the PCI-E modular cable. Still connecting in the same fashion as the previous broken dual cable. The 18/18 would go in the same spot on the connector in the 24 pin as before, and the two split off 18awg cables going to the 10 pin connector at the two different points that the previous 18/22 split off to before. So literally just replacing the 18/22, with an 18/18. Nothing is being flipped, nothing added. Just replacing that cable with a 18/18, following the same exact layout and diagram that the cables originally came in.

Hopefully I laid out the picture better. But yea, I don't want to risk doing any damage, considering it's an x299 platform, a 7940x, full custom water loop, 1080ti, tons of drives, etc.

Oh this is modular power supply.. then yes, with what you've described, you're good.

Phew. Perfect.

Thanks so much guys, you've saved me a wealth of worry and heartbreak. One more thing though just do double check and get double confirmation from what Tsumi said as well. The slightly added extra length of the 18/18 I'm throwing in should be no worry? 600mm for all the cables, except the one I'n substituting in, is around 650mm.

That little difference in length won't matter. Also, 18awg is thicker than 22 awg, which means it can carry more current. Essentially, the only thing you're doing is oversizing the cable, which is never a hazard concern in electronics.