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Drop signal - Soundcraft Si Impact and a Mini Stagebox 32

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Stephen Swaffer:

--- Quote from: Dave Garoutte on May 10, 2021, 03:34:11 pm ---I had a similar issue at a community outdoor event (not mine) with a UI24.
Every time the music got loud it would drop out.
Turns out the 300 FEET of extension cord the park supplied was dropping the voltage down to around 85 volts (measured) causing brown outs to the UI and the Nord on stage.
The UI would reset after a few seconds when the voltage went back up.
Ended up swapping for a smaller analog board and kept the volume down.
After I suggested they put in a 20 amp outlet near the stage, the next year they ran TWO 300 FOOT CORDS!
This is the perfect application for a UPS.

--- End quote ---

If they used the ubiquitous 16 AWG orange cords, #16 wire has 4.89 ohms resistance per 1000 feet.

300 feet of extension cord = 600 feet of wire for math purposes.  4.89*.6K=2.934 ohms.  35 Volts/2.934 ohms=11.9 amps or about 1400 watts-but that is instataneous power-not your average power taking crest factor into account.

Two cords would get you up to 103 volts-assuming an even load.  Put power amps/speakers on one cord and everything else on the other might work.

I agree with Caleb-use an inverter genny and your issue goes away-along with the trip hazard of 300' of extension cord.

Dave Garoutte:

--- Quote from: Stephen Swaffer on May 11, 2021, 12:27:19 pm ---If they used the ubiquitous 16 AWG orange cords, #16 wire has 4.89 ohms resistance per 1000 feet.

300 feet of extension cord = 600 feet of wire for math purposes.  4.89*.6K=2.934 ohms.  35 Volts/2.934 ohms=11.9 amps or about 1400 watts-but that is instataneous power-not your average power taking crest factor into account.

Two cords would get you up to 103 volts-assuming an even load.  Put power amps/speakers on one cord and everything else on the other might work.

I agree with Caleb-use an inverter genny and your issue goes away-along with the trip hazard of 300' of extension cord.

--- End quote ---

It was a loud 5-piece rock band.  3-SOS plus sub,  three monitors, two guitar amps, one keyboard and amp.
I measured the voltage during play, so calculations aside, I did see 85 volts.
I would have happily supplied a genny, but I was only supplying the stage up until the problem.
I have been pointing out all these issues for the several years I've been supplying the stage, but to no avail.

Mac Kerr:

--- Quote from: BMurray on May 10, 2021, 04:19:31 pm ---Oh, good call.   I do have UPS on my stage box, and on my desk...  But I'll make sure they are still working properly.  It's been quite awhile, the batteries may be getting old.

--- End quote ---

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Mac
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Mike Monte:

--- Quote from: Dave Garoutte on May 11, 2021, 12:52:50 pm ---I would have happily supplied a genny, but I was only supplying the stage up until the problem.
I have been pointing out all these issues for the several years I've been supplying the stage, but to no avail.

--- End quote ---

I have the same issue with a Relay for Life gig I do every summer....
I have spec'd (at a discounted rate) the generators that I own (one or two EU3000is') for the stage but the regional rep wouldn't pay to rent them....she expects me to "donate" them.
The power issues were such a mess over the years that one of the local volunteers bought a generator (Predator 4000) a few years ago to use for stage/PA/light power.
The Predator generator is loud but my Itech amps don't seem to mind what it produces.  I bring my Mixwiz to use.


 

Joris Jans2:

--- Quote from: BMurray on May 10, 2021, 04:19:31 pm ---Oh, good call.   I do have UPS on my stage box, and on my desk...  But I'll make sure they are still working properly.  It's been quite awhile, the batteries may be getting old.

--- End quote ---
try what happends if you use 1 UPS and power the stagebox from the very same power source/outlet as the mixing desk.

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