Power issue at an outdoor venue

mikemo6string · #1 06-13-2017, 12:27 PM

I have a monthly gig at an outdoor venue. The power is supplied by a box outside the building where we set up. It's a normal 3 prong outlet, the kind you see encased in plastic outside many buildings. I've done this gig for years, and have never had a sound problem. But last weekend, I was getting intermittent drop outs in my sound system.

The system would cut out for a second, very quickly, and then be fine. It happened regularly throughout the 4 hours I was there. I use one of the outlets, and run an extension cord to my system, about 20 feet away. The other outlet is used by one of the vendors, to power their ice cream machine. We've always shared the outlet.

I was talking to the manager afterwards, and he said the vendor did indeed get some new equipment. Could the demands of their refrigeration equipment be causing this? Perhaps temporary voltage drops? Any other thoughts? I don't know much about this stuff, but always appreciate the knowledge base here.

dannyg1 · #2 06-13-2017, 01:10 PM

Could also be heavy noise on the line causing your power supplies to overheat. You might look into a brownout prevention/auto voltage regulation box. Not so expensive and they work well but they're heavy like lead batteriez

zhunter · #3 06-13-2017, 01:59 PM

Induction motors have high start currents. Two or three or even eight times the running currents for maybe a second or so. Ice cream machines have induction motor powered refrigeration compressors. Probably the compressor start was overloading the power center.

hunter

Mr. Jelly · #4 06-14-2017, 04:07 AM

I think you guys covered it. I'd find a different power source. In the old days power was a major issue in allot of old bars and clubs as they were never built to supply power to all the equipment in a band. We ran extension cords from everywhere. I still have things that can be used to screw into a light bulb outlet so that you can plug into it. There were times after playing for 15 minutes the power would blow and we'd jump off stage and reroute power to get going again. It doesn't do much to help a performance.

mikemo6string · #5 06-14-2017, 10:23 AM

Another option here is providing my own power. I do have a marine battery, and 300W inverter. I use it a few times a year, when power is not available. It's always a bit noisy, though not terribly so. In the past I've used my old Fishman SA220.

I'm running a QSC K10 and a Schertler amp now, and haven't tried this set up with battery power. Plus my pedal board, which has a Strymon Ojai power supply. Do I need a better inverter to use this set up? Or would a better, higher rated, inverter make the set up a little less noisy?

I realize this changes the original post somewhat. It's not very likely that I'll find another outlet to use. I will try a beefier cord, as suggested, but wouldn't mind using the marine battery either.

Thanks, folks.

dannyg1 · #6 06-14-2017, 11:07 AM

For a K10 and a Schertler anything you do need a bigger inverter, I'd say much bigger, like at least 600w and probably 1200w. I'd also suggest a pure sine if you're experiencing noise out. The power supplies of the QSC and the Schertler are probably expensive to replace and anyone who's run live sound in bars and clubs a lot can tell you that bad power kills power supplies. Minimize the problem by using a good pure sine (with a low frequency torroid power supply within). There are plenty of deals to be had on eBay. If you're a purist, stick to Go Power, top range Samlex, Victron or their rebadged versions. You'll be able to get a used 600w for $120 or less.

KevWind · #7 06-14-2017, 11:16 AM

Well possibly .... It is spendy but another option might be to have a power regulation/protection unit.. In the Furman line it starts with this model the P1800AR at $1049 which will keep a steady 120 volts even if the power fluctuates Do not confuse with the cheaper P1800PFR which has protection BUT will not regulate the power.

https://www.sweetwater.com/store/detail/P1800AR

Wyllys · #8 06-14-2017, 12:19 PM

For under $1000.00 you can get either a small Honda or Yamaha inverter generator quiet enough to be no distraction. You'll find many other uses for it in daily life as well.

I have both the Honda EU2000i and 3000i models for off-grid PA jobs. Some of the best money I've ever spent for gear/tools.

ricdoug · #9 06-14-2017, 05:05 PM

Here in California there are a lot of regulations on using generators like cupped spill mats, emissions, exhaust spark arrestors, tested ground rods and permits among a few of the many restrictions. I still have an old Honda EX1000 that travelled around the world with me in the USMC in the 80's and 90's and start it up and run it a couple times a year, but only keep it for backup power.

Recently I read about a new battery discovery where you would recharge batteries with fresh acid at a fueling station an as an engineer, I believe this is a real game changer in portable power in that you can fully recharge a battery in seconds or minutes:

https://www.purdue.edu/newsroom/rele...tomobiles.html

The ice cream vendor's equipment is the culprit and a good Uninterruptible Power Supply (UPS) will help condition those power dips. Ric

mikemo6string · #10 06-17-2017, 08:01 PM

A little update on my system and outdoor power. Although most of my gigs provide A/C power, I had two this weekend that did not. I tried using my marine battery/inverter.

The system really is pretty noisy, even running the Fishman SA220. I did not bother trying to power the Schertler/QSC. In corresponding with folks on this forum, I'm told a better inverter will help. I have a Radio Shack 200W inverter that's pretty old. I read up a bit about inverters, but still don't really know what to choose, or how a better one will allow me to power my more powerful system.

At the gig today, I actually used the battery system that the venue had, which was the Roland BA330. In order to use my pedal board and two additional mics/small mixer, I hooked up my marine battery/inverter. The sound was terrible, noisy and distorted when pushed at all. I ended up scrapping everything but mic and guitar, and kept it very simple. One vocal mic, one guitar straight in and one fiddle straight in. It was fine once I simplified everything, though not a very loud system. I thought initially that since I wasn't running much from the battery/inverter (just the pedal board and mixer), it would sound okay, but it was really poor sound.

I'm not really in the position to drop $1000 on a portable generator, like a Honda or the slightly cheaper options by Briggs and Stratton, Champion or WEN. Perhaps that is the best option, though? And if a better inverter would help, can anyone recommend one?

Thanks for the help. I would like a reliable option when A/C is not available. And the monthly gig that prompted the initial post runs in to November.

krisls · #11 06-17-2017, 11:09 PM

Nuffin' is ever simple..... power off grid by battery...easy.. well....

Just as an example I do some busking. When I want to go light and easy I use the original Street Cube, guitar and mic. If I want a little more power, say a Fair of some sort, I use a Roland AC60 and an old Boss 6 Pedal board. For power I have a 400W PSW inverter run by an 80ah deep cycle battery. Cabinet, trolley and gear weighs about 30kg. But I can get clean power for at least 5 hours.

I did a very rough approximate calc on using a K10 and a basic pedalboard. I reckon you'd need at least an 800w inverter pref pure sine, maybe 1000 -1200. Then a 100 - 120 ah deep cycle battery to give you 4 hours or so of clean power, comfortably. This is sorta off the top of my head though. You need to check the total power draw and time needed and go from there.

Read this to get an idea of the sums needed and what to go for. I use PSW inverters because I did not want any issues with noise/cleanliness of supply. But many say an MSW will work fine, maybe, I have not tried.

Anyway.... http://www.streetmusician.co.uk/buskingpower/

Happy calculating

Kris

dannyg1 · #12 06-17-2017, 11:23 PM

Your need is demonstrably for a reliable pure sine wave inverter. If you identify exactly what you'd like to power, I can offer some ideas. It would be good if we all have this conversation on the forum, rather than privately, so that others might benefit.

There are many inverters that will advertise as 'pure sine' or 'true sine', even some very expensive ones, that don't perform well under different kinds of loads be ause of their design. It might be best for you to skip looking for the cheapest options and look at what has worked well for others (though few here own/use pure sine inverters) or concentrate on models with premium reputations.

The brands/models with the best quality will use low frequency power supplies, as opposed to high frequency switching supplies like those used in computers. Some fairly inexpensive brands have certain models that are good and other models which are not as good (Samlex and Power bright come to mind).

Personally, given that you'd like to power a QSC K10, I'd suggest that you get a 600w or 800/1000w inverter. You should be able to do fine with the 600w and getting the smallest output you can reliably use is a good idea for both system efficiency and ultimately runtime. A larger inverter guarantees that you'll be able to supply all of the power your connected items need to run without stress (and overheating the running hard powered speakers, and whatever else is connected, power supplies, which can lead to an early death of said equipment).

It is possible if you look carefully, to find what you need very affordably and still come up with an excellent inverter. I'm suggesting here that you buy a lightly used inverter and if you need help choosing exactly which one, I'd be glad to offer my help.

I use three inverters now, all pure sine, ranging from 300-600w and the most expensive one I've bought is $130 shipped and that was one of my 300w ones. My 600w, though it sells for around $570 new, I bought for less than $100 in extremely clean used shape.

Be specific about everything that you're considering running and also group together multiple things you might run at once and I'll look up the loads and spec out what I think you'll need (I'm sure that plenty of people will also give their help as well, disagreeing with me entirely no doubt).

By the end of the conversation , you'll be well versed and well advised. I'm sure of it.

dannyg1 · #13 06-17-2017, 11:39 PM

In this thread (link in a sec), I go into excruciating detail of my search for the right 600w inverter. There's plenty to digest in there, though it might be a little much to just dive into. I hope its clearer than mud:

http://www.acousticguitarforum.com/f...light=Inverter

mikemo6string · #14 06-18-2017, 06:35 AM

Here's what I'm powering: QSC K10, Schertler Jam (200), Stymon Ojai power supply (5 500mA individual outputs, all used), Mackie 1202 mixer.

dannyg1 · #15 06-18-2017, 10:25 AM

Quote:

Originally Posted by mikemo6string

Here's what I'm powering: QSC K10, Schertler Jam (200), Stymon Ojai power supply (5 500mA individual outputs, all used), Mackie 1202 mixer.

What kind of levels are you planning to run through this system?

What kind of music and are you a particularly dynamic singer who might be accused of screaming (something like Eddie Feeder or Chris Cornell is what I'm getting at)?