Replacement CU TO SWA or not to SWA

[bryn]

Gents

Your thoughts , I have been to look at a job today in a B&B TNCS supply CU next to meter head then supply to extension 45 amp DP S/W with 40A MCB then off live side of CU in extension feed to Shed and summer house.

Problem

Oh it keeps tripping when we use shower in summer house and new extension new extension shower taking 30A on its own without other shower and rest of Kitchen appliances.

My thoughts were to run new SWA plus new from henleys at meter head to new CU at extension then use 40amp switch from above to feed shed along with Earth rod as original install exporting earth.

Client wants SWA run under first floor floorboards can you see any issues with this for fixing etc.

 

[ianmacd]

Whats the length of the overall run and what other loads are in the 'summer house'?

 

[steptoe]

first Q

what size SWA.?

 

[bryn]

Length of run will be 15 mtrs internal to the extension CU outside summer house is 20mts.

Load on summer house only shower and a couple of sockets for radio etc.

SWA size I was considering putting in 16mm or 25mm tails my concern is running under floorboards easy pull as joists run correct way but may not be able to clip this direct.