Event Power

Why is it important?

Simply put, if the power cuts out during an event it can ruin the experience and create huge amounts of stress for organisers.

All of the services we provide will require power – continuous, clean power.  There is nothing more important than getting power requirements right.  Clean power is especially important for more modern equipment and we will not be able to use digital mixers or evens DSP amplifiers without this – if in doubt, get a Uninterrupted Power Supply (UPS).

LAW: Any event/temporary power system either indoors or out needs to comply with BS7909, and this includes any generators over 6kva.

Indoor Event Power

For most indoor events, this is not a problem.  We come equipped with a selection of 5m and even 10 or 20m cables, so depending on the size of rig you require this is usually not a problem.  If a venue has a sound activated limiting device that trips the power, this can be a serious problem.  Communicate very clearly with the venue about what you intend to do and ask for examples of other bands that have successfully used the space.  For large systems you may need to request a 32amp breakout box.

Outdoor Event Power

There are three methods that are used here in order of preference.

Method 1 – Purpose installed outdoor sockets

If there are outdoor sockets installed at the location where you want to have your event, all you need to do is ensure that those sockets can provide enough power to supply ALL of the companies that might need it on the day (watch out for caterers and bars with electric cookers and fridges).  It might be worth ensuring you have access to the power from the time of us arriving with sound equipment so we can begin tests as soon as possible.

Method 2 – Extensions run from house or building

Obviously all the considerations above apply but also, you need to be aware that circuit breakers on indoor circuits are not designed to work on extremely long cable runs.  You should also only draw 13 amps per socket and not exceed the limits of the ring main.

Method 3 – Generator

By far the last resort as there are a lot of considerations here.

Is the generator reliable?  

Please trust us when we tell you that often they are not.  Put a lot of pressure on your generator supplier to provide guarantees of continuous power, maybe have an engineer on call, spare generator etc.  Our customers have been stung on numerous occasions by generator suppliers.  If the weather is hot, will it continue to run?  What will you do if the power cuts out?  If the power does cut out, we need to power all our audio equipment down and do a staged start up – so allow time for this.  Equipment can also be damaged by voltage drops.

Will the generator be used safely? 

If you have a three phase generator, it is possible to draw current from it in an unbalanced manner that can cause a massive surge in voltage.  They also need to be grounded with a copper rod.  For anything that is a large system (including those over 6 kva) BS7909 states that a competent person is on site for the event to sign off the system – and any unforeseen changes to the system.  The same applies if multiple users are taking power from a single generator – it needs coordinating.  The larger the system, the greater the experience that will be required.  Eg. 3 phase generators or generator switching equipment are beyond our knowledge at Complete Music and Sound. 

Noise and fumes?  

A generator produces noise and fumes.  Where you locate the generator will affect the experience on stage and for people around it.  Most larger generators are silenced but ask for the decibel output of the equipment.  As a rule, petrol generators are very loud and not well suited to live music.

How will you get the generator? 

It is worth pointing out that they are seriously heavy.  180kg for 6Kva is typical, much more for larger ones.  Therefore, a large vehicle will need access to the site if you need a substantial generator delivered.

Output and Specs? 

A generator has its output measured in KVA.  Please be aware that although similar, this is not the same as watts – it will be slightly more than the wattage.  A generator has a slightly variable output and you need to accommodate this.  You also need to accommodate the resistance of cable runs etc.  A 20% margin is recommended as a minimum.


Most generators that are large enough for events also have a generous fuel tank, but someone needs to take responsibility for checking it from time to time.  Otherwise it is bound to cut out halfway through the headline act!  

For ALL event power it is recommended that you:

  • Check any elements of the system that are outside have appropriate IP rating
  • As a principal contractor nominate a senior person responsible
  • Consider emergency electric requirements – e.g. for announcements or lighting
  • Read this short document produced by Richmond Council 
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