Mains Electricity for Touring PA Installations

Most modern venues will have a suitable power supply, but some performance spaces (village halls, private houses, fields...) may not have. The main concerns are:

1.  Safety. In any working environment - but especially one that is open to the public - electrical safety is a legal requirement, not just an inconvenient bit of bureaucracy that only bothers bloody-minded technicians.

For a supply to be safe, Live, Neutral & Earth connectors must be wired correctly, and the earth connection must be suitably grounded (particularly with portable generators). Any potential leakage of current to earth should be prevented by use of appropriate circuit breaking devices. Circuits should be protected against overloading (see current ratings, below). A basic 13 amp socket tester is inexpensive, and can instantly show whether the socket is wired correctly and earthed. 

We provide additional protection for our own equipment and personnel by using our own (RCCBO & RCD) circuit protectors, and advise anyone else to do the same: a 30mA RCD can be obtained from any DIY shop, typically for less than $10. Always use one, and test it using its Test button every time you use it. Don't let anyone persuade you that keeping the power amps running is more important than avoiding electrocution.

2.  Current ratings. You need enough juice to supply all the amplifiers, all the back-line, all the stage lights, the mixer(s) and the rack lights: the whole show. If the sound and lighting equipment shares a single 13A socket (or, shares a standard 20 or 32 Amp ring circuit with other equipment), there is the possibility of circuit overload. In most cases this will result in the circuit tripping out or a fuse blowing, which won't be much more than a nuisance. However, in some cases it could also present a danger. Note, for example, that a 13A extension reel is only rated at 13A when the reel is fully unwound. Try to draw 13 amps through it without unwinding it and it will get dangerously hot.

Most working venues will have adequate power for the sound and lighting systems, as well as a technician who will be able to advise you. However, the same is not always true of many hotels, social clubs, village halls or other institutions that may put on events. An extension lead from the house to a marquee in the garden might not be enough, especially when someone plugs a space heater into it at the same time as the kettle goes on in the kitchen. If you are in any doubt about whether the power supply will cope with the whole sound & lighting system's requirements, check it out - or if we are involved, talk to us - in plenty of time (days or weeks, not hours or minutes) before the show.

3.  Connections. All the power in the world will be useless without the correct connectors. While 13A 3-pin plugs and sockets are standard for domestic equipment, other mains connectors are often used for portable equipment (and many theatres still use 15A round-pin plugs and sockets for lighting). Most touring PA systems use blue "Ceeform" connectors (our own systems use 32A connectors for sound, and 16A for lighting). Some venues have all varieties available on stage, but several we go to have only 63A outlets. There is no safe way to get power from a 63A Ceeform socket without using a 63A Ceeform plug. In addition, some Ceeform sockets cannot be switched on at all without a matching plug inserted.

This means you should always:

•  Check with the venue and make sure you take the right connectors;

•  Carry adaptors for common variations (13A to IEC or "kettle leads", 16A IEC to 13A, etc).

Never "bodge" mains connections with insulating tape, or take other dangerous shortcuts.