cable gauges

[omartinez]

Well, Im in the middle of my lex fixture design and my controller. I've a couple on troubles deciding which cable gauge to use for some applications.

1. Just run out of cable to wire my led fixture. My aquastyleonline kit came with 18 gauge cable (i think...it says 0.5mm2). Can i use 22 gauge cable that i've for electronics projects to wire the leds?

2. I need to comunicate the power box of the led fixture to my diy controller, i need to pass 4 5V PWM signals (for each led channel) and 12V power to power the controller itself. I'm planning on using DB9 (DB9) cable for that, it is good? the gauge of that cable can pass 12V?

also i accept any recommendations

[Landsailor]

Don't worry about voltage. Any wire can carry any voltage you'll use in this hobby. The insulation on anything you buy should be rated for at least 300V.

Current (ampacity) is the concern with conductor sizing. Too small of a wire for a given current and you have a fuse. Metric wire sizes use surface area of a cross section of the wire (so does AWG once you get bigger than 4/0).

Your .5mm square surface area is 20AWG.

That said, 22AWG is rated for up to 7 amps.

As for the signaling, I can't comment to that for sure, but it will probably work...might not, though. You might have to use shielded pairs depending on the length of the run and other sources of electrical noise.

[omartinez]

each led string will run at 660ma, so if the 22AWG is rated at 7amp that will do, right?

the cable i will use is a standard db9 serial cable (used for external modem or rs232 comunication). I believe is shielded. i think on that cable the 5V signal will do good, my concern is the 12V power i intent to also run.

[kcress]

All fine..