Incidentally, in Australia, we rate (240V) cords by 'AMP rating' (not wire gauges, but the rules are there as to which gauges of wire to use for what ratings, both fixed and cords) 5, 7.5, 10 & 15 amp ratings. This is how things are advertised and marked for sale - just the 'rating' figure. All except the last come with '10A' rated (except for some lower rated appliances) plugs and sockets, the 15A one has a larger earth pin, so you can't plug it into 'normal' 10A rated sockets - it IS possible to plug a 10A plug into a 15A socket. It is possible to obtain ext cords with 15A cable and 10A plugs (marked as such) - intended as 'long' 'temporary' cords for caravans, building sites, etc. Fixed wiring for 'domestic' use is normally rated at 20A & 40A - lighting runs may have lighter gauges, eg 10A.

Note that now, all 'normal' (10A rated) appliance and extension plugs sold in Australia must have a narrowing of the part of the pins closest to the plug body so that some insulation is present if the plug is partly 'pulled' - this MAY cause some loading problems due to the lesser amount of metal in the plug pins, especially for long cords.

I once saw a hired cord used in theatre lighting - a Loooong one which had about 20 feet wrapped around a 2 inch diameter water pipe (used to suspend theatre lights from) which had melted, and finally blown the fuse! The hiring guy kept it to demonstrate at regular 'lighting seminars' just what idiots will do, and what not to do. And yes, I did met the clown who had done it, and he was a natural disaster walking around waiting to happen - a 'know everything ignoramus' - and he 'happened' to me several times, dammit...

When running cords thru areas with traffic (including foot) they should be suspended well clear of the ground - if buried (normally for 'permanent' installations), there are minimum depths and recommended coverings, such as broken rubble, etc below the top layer of dirt. Incidentally, the AGMF in Toowoomba was ignoring all these safety regs when I stumbled over the cords the other year - all attempts to get the authorities to enforce the laws (including the permitted noise levels!) have not worked - why would 'God Botherers' need to worry about that sort of thing? Render unto Caesar, oh... :)

Maleny Festival on its new grounds futzed around with generators and festoons of extension cables and double adaptors the first year, then bit the bullet and had the professionals run real mains power poles (and proper feed transformers, etc) around the place for the next year... this solved the endless power juggling, brownouts and fuse blowings as every stall holder constantly plugged and unplugged things!

Oh, and for real high power users, 3 phase feed is recommended, especially by the power companies!

By the way - get professional electricians to have a look at whay you are trying to do - it's cheaperin teh long run than the inevitable life insurance claims...