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Splitting sound/lighting on generator


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Hey,

We have been Putting on events for about 200/300 people using an RCF rig (about 4kw) and our lighting set up (3Kw). most the lighting is LED but its the strobes and the smoke machines that use most of the power.

Up until now, we have been hiring two generators, one for sound and one for lights.

But we would like to buy one, and are wondering if we could run it all off one (maybe 10 Kva?) generator, and if so how would we split them?

would we use 3 phase?

and would we need to isolate both circuits?

Ive heard lots of stories about this causing interference and sometimes a humming sound?

Any advise?

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Just three tiny pieces of advice Marla.

1) Use a spellchecker.

2) Fill in your profile a bit more.

and

3) Get an electrician.

 

Welcome to BR and before you assume I am being silly, sarky or stupid think about it. People talk to amateurs differently to professionals and merely asking questions about electrical supply raise the possibility that you should not be messing with it in the first place. It is dangerous stuff especially in big lumps like 10kVa. Even more so in public.

 

If you are working in a commercial environment (getting paid, selling tickets) and playing with power with no competence level then nobody here with any sense is going to advise you.

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Iv done festival events where lights, sound, projection, emergency/site lighting, bars/merch etc, catering .... Have all shared gen-sets.- And providing someone has put some thought into what draws what, not just in relation to total genny capacity but how many feeds of what per phase need going where, phase balancing (and not just at an all on), what wants RCDing and at what values, earthing etc - it has all worked out fine (for the most part).

 

But as Kerry has already alluded to if you don't know how to do these things, which your question implies, then buzzing is the least of your worries.

If your hiring anything of serious size from somewhere reputable Id expect it to come with someone who knows what they're doing, if you buy your own that someone becomes you.

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A 10KVA single phase genset (with a decent voltage regulator) would probably run that kit without issues, except for the strobes; if they are atomic class strobes they'll probably play havoc with a genset that small.

 

There wont be any hum or interference as long as your sound system is correctly built of adequate components throughout.

 

Thirding the advice on sonsulting someone familiar with this stuff.

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Assuming that you NEED generators, you really are in the middle of nowhere, you really need some provision for emergencies especially main genset failure. If you have two gensets then it's less likely that both will fail together.

 

Consider that a crowd deserving a 10K genset also deserve adequate emergency lighting -which may need a genset of its own.

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Hello

 

As a fully NICEIC registered electrician and company I agree strongly with all the views from our fellow members Please don't play with this. Although I no longer do outdoor events worked on many and supported several companies who do on a large scale I had thought of the following.

 

If you are thinking of buying a Generator you also need to take into account the following.

 

Transport

Storage

Insurance

Fuel costs

fuel storage

barriers and fire equipment

service and repair costs

will it ever be big enough!

Suitable mains distro which will need certification or patt testing

 

Just thought I would bring in another angle for your thought.

 

Please stay safe and remember you are responsible for yourself and others around you whether paid or not. Protect your fellow friends and the public and do your risk assessments.

 

Perhaps give up and hire a company who professionally provides this service may also be cheaper for you and supports our industry?

 

email was written in all good intentions

 

Chris

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Just to keep things in perspective here. Many of the high profile events companies in the UK employ little more than cheap labour to plug up their electrical systems, sometimes under the supervision of seasoned lampies who may or may not hold an electrical certificate of some sort, and most likely have little experience outwith the entertainment field.

 

I'm a JIB graded electrician myself with a traditional apprenticeship and 30 years of wide ranging experience including steelworks, construction, theatre, factories etc. However, I'm not pretentious enough to think that people shouldn't be allowed to buy a generator and plug up their own gear. If they were wrapping wires round wingnuts with no protection in sight then I would get alarmed, but if they get a proper generator system with suitable connectors and distribution equipment then the risk of an electrical accident is relatively low.

 

Now back to the original post.

 

As mentioned earlier, the atomik style strobes are a very nasty load, usually in the form of extremely high current spikes. Ordinary traditional capacitor based strobes on the other hand are fine. The smoke machines have a heating element in them which will vary in power rating with the model and output, but they are likely to be in the region of 3 or 4 Amps per unit. LED arrays are pretty low power and should pose no serious issues.

 

It's important with outdoor rigs to use plenty of RCD (Residual Current Device) breakers to protect several circuits so that if there is a fault or water ingress issue then you don't lose the whole show. Your load isn't excessively high, so you could use a generator with a suitably rated Cee-form outlet plugged directly to a small professionally manufactured distribution unit that has a suitably protected set of Cee-form outlets. If using an RCD on the generator then it's better to get the type with a slight time delay and perhaps 100mA trip current to allow faults to provide local protection, but to allow equipment faults to clear on one of the sub RCD breakers.

 

Does it all sound gobbledy-gook? If you talk to a proper generator supply company they should be able to give you all the advice you need to put together a useful and safe system.

 

Oh, and being NICEIC approved isn't something anyone should brag about these days.

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Thank you 8 points

 

1 Noted 30 years.

2 Well done you span my life time!

3 Very proud of my costly registration

4 Will continue to promote the NICEIC

5 Actively raising awareness of maintaining standards in the lighting and sound industry

6 Employed and contracted many JIB electricians of all ages to have discovered disgraceful work practices

7 Currently employ 2 JIB electricians our supervisor has 28 years also with traditional apprenticeship almost killed me to find the best

8 Happily stand corrected with regard to the purchase of generator

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leaving aside for now whether the op should buy a generator or not and whether they are competant or not........

 

for the first 10 years or so of my life in this industry I was always tought to never mix sound and light on the same power supply. venues I worked in had completely seperate sound and lighting supplies (as this is what riders demanded) in smaller venues sound and lights always got different ring mains. on 3 phase generators we tended to run sounsd on 1 phase and lighting across the other two.

 

dimmers made PA systems hum if they werenot off or on full, strobes made the PA click, smoke machines made noises through the PA when the heaters switchee on/off. and catering and VL6 racks were not alowed anywhere near a socket that was on the "PA supply"

 

so some (cough) years later and PA , lights, video, catering etc are all co-exsisting on the same electric supply. Its a good few years since I asked for seperate sound and light power feeds at a festival.

 

is it just the equipment is all much better these days or am I getting lazy in my old age?

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is it just the equipment is all much better these days or am I getting lazy in my old age?

Sound people finally discovered star earthing, and that balanced signals really are better than unbalanced. No black magic needed.

 

I suspect the reason sound people discovered earthing was that PA speakers became monumentally less efficient at converting electricity to noise, so they needed more kilowatts than you could get out of small number of standard outlets, and thus sound people got distros, and that gave them star earthing. So without anyone actually understanding what the heck they were doing or why, the probelm was solved.

 

Time was when a few hundred watts of PA through horrible horn loaded speakers was really loud. Ok, it sounded shit, but it were loud...

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is it just the equipment is all much better these days or am I getting lazy in my old age?

 

Another factor was a marked improvement in equipment screening and earthing, reduction of emissions and susceptibility to emissions when the EMC regs came in some years ago.

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