Hi all.
Here's a pic of some 90 deg molex drive connectors I'm planning on using to mod my Sonata with. Pic swiped from Digikey.


As you all know, the Sonata can mount 4 hard drives in a rack rotated 90 deg from the rest of the case and horizontal with the bottom. The idea is to run new wires spliced into the drive power wires and space four of these connectors about 2-3 inches apart. That way, you can have all four drive bays filled (ala SCSI or RAID) and only use one power cable to connect them all.
This might be a good mod for other drives as well (CD, DVD, etc.)

Here's the Digikey part numbers for those interested.
WM6981-ND ($1.56 in lots of ten)
They come pre-pinned.

Alternatively, you should be able to build an adapter with four of these connectors terminated with one of the female plugs (4-pin fan plug) to keep from cutting your wiring harness (warranty issues) or just for increased length. The female plug part number from Digikey is: WM6985-ND (out of stock)


What's everyone think?

Wow... thanks for the research. I'll be ordering some of those. Looks like a very tidy way to clean up the HD area in the Sonata.

What is the power / current rating of the wiring / molex.

4 or more SCSI drives will need thickish wires.

The 90deg plugs are rated for up to 16AWG gauge wire which should handle plenty of Amps for drive usage.

The straight pin plugs use pins that are rated between 13-20AWG gauge wires so there should be no problems.

I plan on buying these in mid-June so if anyone wants some, let me know and I'll boost my order and mail them out to people at cost plus a first-class stamp (or whatever postage).

There should still be some headroom with 4 drives. IIRC, each contact can take 5A, but the wire itself is around 7A. I bet most SCSI drives are around 1A for each of the 5V & 12V lines. That's to the best of my recollection.

[quote=" I bet most SCSI drives are around 1A for each of the 5V & 12V lines. That's to the best of my recollection.[/quote]

No

The Baracuda 7200.7 datasheet says 2.8A max.
SCSI drives would be more than that, so that gives one per connector

That 2.8A figure must be @ spin up because under seeking it's < 13 watts, which works out to about 1A+ on the 12V line. Seems like it consumes 0A on the 5V line or whatever "N/A" means. The Cheetah15k consumes about the same on the 12V line + ~1A on the 5V line as I guessed: http://www.seagate.com/docs/pdf/datashe ... 001_06.pdf

I guess it boils down to how well the connectors/cables can withstand the current/heat for short durations - maybe like 3 seconds for spin up. Can any EE pitch in with some info/experience?

Well for the mod I plan to do, I'm just going to cut off the existing connectors, and wire these plugs instead for a cleaner look. I'm pretty sure the wires coming from the power supply are 16-18 gauge. Since I'm using existing wiring, I shouldn't have problems.

For those of you planning an adapter harness, I'd go with 16 gauge just to be safe.

I used to own a really large tower with 7 hard drive bays rotated like the Sonata. It was a Macintosh from a company called Daystar. It was the Daystar Millenium and had three high speed 120mm fans (one exhaust, two mounted behind the drive bays like the sonata.)
The fans were so powerful, they'd pick up a sheet of paper off of the floor and suck it tight against the front intake!
Anyway, back to the thread. This massive case had cabling for 7 SCSI hard drives to fill all the bays. There was only one cable strand and they all had the above 90deg connectors (eight of them, one spare) all on one strand. The power cable used is the same used today (16-18 gauge).

If you look carefully at the picture, you can see the 12 DIMM slots (that's right folks, twelve!)

OK, I hope you people are satisfied! I had to dig out my engineering books for this one!

To compute the relative resistance of two foot strand of 18 AWG copper wire;
R= 10.37 x 2/1624 [specific resistance of copper at 20*C x 2 feet / circular mil]
R= 0.0128 Ohms

Relative conductance of two foot strand of 18 AWG copper wire
G=1624/(10.37 x 2)
G= 78.30 Mhos

Now to compute the maximum current carrying capability of the copper;
I=E/R
I=5V/0.0128 Ohms
I=390 Amps (max amperage before copper core meltdown!)
Now the copper core will heat up and it's this heat build up that will meltdown the insulation long before the copper melts. Below is a cut/paste of a chart in my electrical engineering book (but is also referenced here)

Allowable Carrying Capacities of Copper Wire
(Regulations of the National Board of Fire Underwriters)

Size,...Diameter, mils........Cross section,....Amperes..........R
B&B....(1 mil = 10^-3in.).....circular mil....Thermoplastic.....ohms/1000 ft
Gauge.....................................................insulation
10........101.9........................10380...............30..................1.0
12........80.81........................6530.................25..................1.6
14........64.08........................4107.................20..................2.5
16........50.82........................2583.................10..................4.0
18........40.30........................1624.................5....................6.4

Sorry if the table looks like crap.
Basically, 18AWG wire has a cross section of 1624 circular mils and 6.4 Ohms per 1000 feet.
And....
It looks like for 18 Gauge wire, 5 Amps is the max;
and for 16 Gauge wire, 10 Amps is the max.

The max power draw for a hard drive occurs at initial spinup. So if the max current draw rating of these drives are 2.8A then using 16AWG wire you should be safe connecting three drives (2.8A x 3 = 8.4A)

Maybe four or five drives if they're rated less.

Hope this answers everyones questions.

My brain hurts now. I hope you're happy!