eSATA on the PSU

[Amaron]

Wasn't sure if this should go in PSU or Electronics forum so my appologies if this is the wrong place.

Recently I upgraded and I noticed the mobo came with an eSATA bracket. This bracket surprised me because it has a female 4 pin molex connector on the back which hooks up to the PSU: picture.

I would really like to use something like this to power some 3.5" eSATA drives + 120mm fan in an old SCSI enclosure I have sitting around. I need to know what kind of safe max cable distance I can go for on normal 4 pin molex though? My PSU is an Antech Truepower New 750W. The hard drives are undecided at the moment.

Also is it ok to put 4pin molex cables outside the case like this? I'm assuming they aren't properly shielded from causing em interference. Is there some sort of external power cable I could use in this situation? Any other suggestions on achieving what I want are welcome as well. Thank you for any info anyone can provide.

[Makalu]

well after the drives spin up it won't use very much power...I reckon you can go as far as voltage drop along the wire allows...shouldn't be much voltage drop at those current levels though. I wouldn't think there'd be much EMI either...many people run open bench set-ups without excessive EMI problems...if you do have some EMI from the setup you can buy a ferrite ring for cheap and coil the wires around it

[Amaron]

Well my main worry is safety factor. Even the 12v rail the molex's run off of could run a lot of amps if a partial short happened right? From what I can look up it looks like 2 meters is kind of on the edge of where you should switch from 16 gauge to 14 gauge at the kind of amps a PSU can put out.

I'm just a noob at electrical stuff though so I'm unsure of whether or not this is something to really worry about.

[Makalu]

well I wouldn't worry too much about it...certainly it's safer than what can happen on all the mains voltage cords we have running around. Anyway the unit should shut down at 240VA (20A on the 12V) under a short condition...even a single 12V rail unit should have that short circuit protection. And most multiple 12V rail also have over current protection set somewhere around 240VA. If for some reason a unit didn't shut down then yeah that could start a fire...but using a heavier gauge wire is less safe not more safe because now you've provided it with even greater current carrying capacity before it burns thru or whatever...really I wouldn't worry about it...