Forget the outboard quipment - that's only peanuts in terms of power used.
Add up the power output of your PA amplifiers - multiply by two.
Add up the power output of your guitar amplifiers - multiply by three
Add these togther to get an approximate value for total watts needed.
In thoery you can take up to 3000 watts from a 13A socket, and rings are often rated 20 or 30 amps so you can have perhaps 6 or 9,000 watts total over a number of sockets - need to examine the fuse box if possible. I really wouldn't recomend taking more than 2000 watts off any one socket since dirty ones tend to over heat and eventually the 13A fuse can blow.
BUT 1. If you have an old fashioned lighting rig (not an LED one) then you need to take this into account (- which is why I used to wire in tails when the venue provided a box - we had about 3K PA and 20K of lights)
2. Many venues have crap wiring (I call it "landlords wiring" because he did it himself rather then calling the electrician - see most pubs in Britian). So best not to pull everything off one socket.
Hope this helps.
Edited by PSR (27/11/10 06:11 PM)