Safe current draw on PSU leads and PSU wire management

[DougLite]

I have a server box, relevant [H]ard|Ware:

Tyan S1862, 2x PIII 550 Katmais, 512MB of RAM
Voodoo 3
Antec True430

Fujitsu MAP3367NP 36GB 10K SCSI (~1A on +12)
IBM DDYS 18GB 10K SCSI (~1.2A on +12)
2x Seagate ST173404LCV 73GB 1.6" 10K SCSI (~1.5A +12 each, on staggered spinup)
2x Maxtor 6x200P0 200GB 7200RPM (~1A on +12 each)

I will add another 7200RPM drive, possibly today if I cash in on the deal at Fry's. Another SCSI drive is also a possibility. In the distant future, I may add a 5in3 SATA setup, but that will have it's own dedicated wiring from the PSU and is not a factor in these calculations.

I would like to clean up the wiring in the case a little. With 26A on +12 and no CPU or GPU draw on +12, the PSU obviously has plenty of juice...but how much +12 can you safely send down one (I'm guessing) 18 AWG wire? Am I correct in believing that I should try to keep the draw down any one wire to 8A on +12 or less, or am I just paranoid? Right now, I'm looking at a worst case spinup draw of about 13A on +12, and a typical operating draw of around 7.2A. These figures may go as high as 15A on spinup and 8.5A for typical operation. That 15A figure = in my mind, should I go with two leads from the PSU for this project?

Also, I'm a total n00b to modding...whereabouts can I get the equipment to crimp on/vampire tap in-line Molex connectors?

 

[Frank4d]

8 amps is about the max you want on one wire for a couple of reasons:
- Molex pins and connectors are rated about 7-9 amps max.
- Voltage drop in a wire is a function of current through it and wire size and length. For 18 awg wire the voltage drop (in volts) is about .0064 x length (in feet) x current (in amps).