Did extension cable

Well as long as it does not exceed thefuse you put in the socket bar and that is set below the one in the plug. It may not be pretty, but I'd expect it to work. Brian

Use the 1.5mm^2 T&E, it will be much easier to wire into a plug and extension socket and has more than enough current carrying capacity (20A) for the job. You may have difficulty getting the cable into the cord grip on the trailing socket, depending on its design.

(note the lead will only be suitable for mostly "fixed" applications - any significant repeated flexing will eventually fatigue the solid conductors and break it)

Non-expert diy view from me. Don't use the solid wire cable, as it is not designed for flexible use, and if you fix it semi-permanently it is likely to create a risk in future if someone uses it for something else. Get 6m of 1.5mm^2 flex and use a 3A fuse in the plug. Mark the extension with a label (to remind yourself) saying "maximum 500W" and route the extension lead as far as possible where no-one will trip over it. This is not the best way to do it, an extension of the fixed wiring following the wiring regulations would be better, but you would then have to go to a lot more trouble, probably.

TW&E is for permanent installations. An extension lead needs flexible cable - not single core stuff like TW&E.

ok if fixed in place and unwired at end of use

NT

Brian Gaff brought next idea :

Apart from the fact that twin and earth is designed only to be used on fixed wiring and tends to break if moved as would a portable extension.

Even more so given the OP states his old one has had a hard life.

BTW, it's usually cheaper to buy a ready made one from the likes of Lidl or any other reliable place. Rather than buy the individual parts and make it yourself.

The OP describes a semi-permanent installation some of which is likely to be switched on all the time which is going to use less than 1A. What is not to like about protecting it from currents higher than 3A under fault conditions where it could overheat?

It would also be bad practice to use the semi-permanent extension for other appliances and a little note on the sockets to that effect, and the current limit, would be good.

too many errors.

Name one!

Last time I looked you can generally buy a ready made extension lead for less than the sum of the parts from a wholesaler. And a lot less than from a shed.

Well I would use a 5A fuse. But that is not an error just my difference of opinion.

Or is it because I have run out of 3A fuses:-)?