So today I started the job and the back plate on the replacement socket was too big,  a quick tour taking in five wholesalers was unsuccessful as they don't stock them, however Toolstation do, still slightly bigger but rearranging the layout sorted that.

Time allocated a couple of hours,  time taken over half a day for a simple job replacing a socket and testing three boards, along with the paperwork. 

I suspect the problem was daisy chained distribution boards with 16 amp leads rather than 32 amp.

I

So today I started the job and the back plate on the replacement socket was too big,  a quick tour taking in five wholesalers was unsuccessful as they don't stock them, however Toolstation do, still slightly bigger but rearranging the layout sorted that.

Time allocated a couple of hours,  time taken over half a day for a simple job replacing a socket and testing three boards, along with the paperwork. 

I suspect the problem was daisy chained distribution boards with 16 amp leads rather than 32 amp.

I

In the good ones there is a 16A MCB or RCBO per 16A socket when the input is 32A single or 3phase. Thee are some designs that do not do that,  where you can take up to the whole 32A from one 16A skt so long as you do not load the others heavily.

But equally you can get failures for all the normal reasons, corrosion, not fully pushed in, loose wiring in the plug etc all adding an extra half an ohm and resulting in an inability to take the full load.

I do recall adverts for a little wire 'bottle brush' for those sorts of sockets to keep the self heating down,  but I have not seen one in the wild  for years, so  I suspect i is too easy to get  shock off it though.

Mike.