240 volt (240V) is the power supply that we use in the UK in our homes and what most standard non-industrial equipment uses to power it. This includes fridges, coffee makers, kettles, mobile phone chargers, lighting etc. This is single phase power. The difference between Single and Three phase power will be covered another time.
Power to your event or stand is very simple to understand and very easy to calculate. You will have heard the terms watts, kilowatts and amps floating around when your designer asks for a list of what all you need on your event. They are all just units of measurement to explain how much power something uses. There are 1000 watts (1000W) in a kilowatt (1kW) and 1 amp (1A) equals 240 watts (240W). So to convert from amps to watts or kilowatts, you just use some simple maths. 1 amp (1A) equals 240 watts (240W) so 4A equals 960W (4 x 240) or just less than a kilowatt. Similarly, 3 kilowatts (3000W) is the same as 12.5 amps (3000/240). So this way you can either multiply or divide to get the figures you need. And once you know all the figures for the pieces of equipment you have, just add them all up and it will give you the total supply you need.
There are limits to what each cable can carry, what each plug can cope with, what each breaker or fuse trips at and ultimately there is a limit to the main supply to your stand or event. So you need to know all the bits of equipment you want to plug in so you can work out whats needed so the whole system will work and work safely. Good designers will always make sure there is a bit of spare in all their calculations for last minute additions! As an aside, when you order a power supply to a trade stand, it will either be in individual sockets, which are usually specified in watts (500W, 1kW or 3kW), or a single big outlet which you will plug distribution equipment into and it is specified in Amps. Events usually have a supply provided from a building or a generator. And now you know how to change between the two and why its a real pain when someone adds a 3000W kettle to the mix when it wasn’t designed for!
We have put a spreadsheet together which is downloadable here which will do the maths for you but essentially, its all just adding, multiplying or dividing to get the answers you need.
And if you want some free help with your calculations, please contact Iain on firstname.lastname@example.org or call on +44(0)141 248 8330.