soup said the following on 27/09/2005 17:25:
Does anyone have a favourite site, to work out the CSA required for a
piece of cable, basically I want to make up an extension to run a
circular saw (1200 W) [at 240V that is 5A] asked the chap in the local
Hardware shop for cable large enough to deal with 2 kilowatt (mmm over
speccing as usual), he said he had nothing that could deal with that
much power 2k was "cooker sized", but my kettle (e.g.) is 2200 W, so
can't trust him as far as I can throw him.

The IEE Wiring Regulations (BS7671) provide tables of the current
carrying capacity of cables.

For your example, PVC flexible cord for extension cables to BS6500 is
covered in table 4H3A:

2kW @ 230V implies a current of 8.7 Amps. You should therefore use as a
minimum 1.0 sq mm flex, which has a rating of 10 Amps. You would need to
put a 10 Amp fuse in the plug.

However, you should consider using 1.25 sq mm flex which has a rating of
13 Amps and therefore allows you to use a standard 13 Amp fuse in your plug.

Most extension cables rated at 13A you buy in DIY sheds will be made
with 1.25 sq mm flex.

If you want to run a largish load at a long distance, you should
consider using 1.5 sq mm flex, which will have a lower voltage drop.

You could also look he

http://www.tlc-direct.co.uk/Technica...ltageDrop.html