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120v 75' run, which gauge?

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Matt Vivlamore:
I've got a gig coming up where I've got make 5x 75' extension cords to the stage.  Will I be fine with 12awg, OR do I need to step it up to a 10awg?  I won't have access to a 240v plug; I am plugging into a 8x 20amp panel with Edison outlets.  Also, I doubt I'll be pushing the PA hard on this gig, it's mostly folk and light rock. 

Since, I am in rebuilding mod and was going to buy a spool of Power Cable and after the gigI was going to take a couple of the 75' and chop them up to 25' and 50' (if I can stick with 12awg).

My plan for power:
1) SR: SRX812P, SRX828SP and couple LED lights
2) SL: SRX812P, SRX828SP and couple LED lights
3) X32-rack & SD16, laptop, iPhone/iPad chargers, fan
4) 4x RCF NX12SMA and front stage power for the bands
5) Power for band backline

Tim McCulloch:

--- Quote from: Matt Vivlamore on August 14, 2021, 03:23:20 PM ---I've got a gig coming up where I've got make 5x 75' extension cords to the stage.  Will I be fine with 12awg, OR do I need to step it up to a 10awg?  I won't have access to a 240v plug; I am plugging into a 8x 20amp panel with Edison outlets.  Also, I doubt I'll be pushing the PA hard on this gig, it's mostly folk and light rock. 

Since, I am in rebuilding mod and was going to buy a spool of Power Cable and after the gigI was going to take a couple of the 75' and chop them up to 25' and 50' (if I can stick with 12awg).

My plan for power:
1) SR: SRX812P, SRX828SP and couple LED lights
2) SL: SRX812P, SRX828SP and couple LED lights
3) X32-rack & SD16, laptop, iPhone/iPad chargers, fan
4) 4x RCF NX12SMA and front stage power for the bands
5) Power for band backline

--- End quote ---

12 will work.

Jeff Lelko:
Iíll second the vote that 12 should be fine.  The only time Iíll dropped to 10 or even 8 is when I need a few hundred feet running to equipment with a high continuous current draw that has little tolerance for voltage drops (i.e. discharge moving lights).

Keep in mind too that once you drop below 12 SOOW youíll have difficulty getting a PowerCon connector to fit properly.  Hope this helps!

Brian Adams:
I agree with the other, for a 75' run at 20a, 12ga is totally fine. That's what I'd use, anyway.

Brian Jojade:
If you start with 120 volts, a 75' run of 12 gauge wire at 20 amps would give you a voltage drop of around 6 volts.  Upgrading to 10 gauge wire would reduce the voltage drop to about 3.75 volts. 

The power draw for your plan looks to be around 10 amps even if you drive the system into hard clipping (1/3 power on the speakers), but will likely be lower than that for most of the show.  You may see some sudden fluctuation in the voltage with hard peaks, but the equipment you're using doesn't care all that much.

Generally speaking, #12 would be acceptable for runs up to 100 feet on a 20 amp circuit. 

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