Old time sparkie

[Ian Roberts]

Passed C &G 236 parts 1 and 2 in 1989 but been out the game for over 20 years, but always done my own home electrics. My lastest home has gave me a bit of food for thought and would like some advice. Am having a concrete garage at bottom of garden, and in my home is a radial circuit feeding only 1 twin socket at ceiling level for a Tv in bedroom. On looking at wiring in loft it's fed from a 10mm T &E into a JB. From this T &E 2.5 into socket. I'm looking at extending this radial with 2.5 to a 20amp DP Switch, then out to a weatherproof socket on external wall. From this weatherproof socket I'm terminating 4mm SWA with external  glands to go to garage which will only be feeding 2 twin sockets and a 3 amp spur for 1 light. My question is is it acceptable to place a DP switch in radial AFTER the original socket in bedroom? Thanks for any advice on this? 

 

[Evans Electric]

Is that 10mm  an redundant shower circuit  or is it still the shower supply ?   

You need to downrate the fuse on the 10mm to protect the 2.5mm .

I assume the 4mm is to cover volt drop. 

Can't see a problem with the DP isolator .....its good practice to be able to isolate outgoing subs like that . 

Stand by for the PME  earthing and  not being registered for domestic work .   

 

[binky]

Think I would rather connect to the 10mm, but as long as you are derating the MCB to protect the cable, there is nothibg wrong with your plan as far as I can see.

 

[Ian Roberts]

Yes lads, looks like they've nicked the feed from old shower. Mcb type B 16 amp feeding  radial. And 4 mm is for volt drop and I was also given it! No extraneous metals as no services going in. Literally glorified shed with a couple of fluorescent/led lights and a couple of twin sockets. Sockets for chest freezer and under counter fridge, other one for strimmer, mower etc. Shower is now fed off gas boiler 

 

[Evans Electric]

Well it sounds good to go .     You'll need an RCD  to cover the whole circuit as you have  ...I'm guessing ...cables  buried in walls , sockets ..sockets outside .  

You have a 16A breaker and I'd say the expected maximum load would be  almost zero  with the TV socket  using occasionally 1A   , the  garden socket  using zero  Amps  99% of the time   and the glorified shed  an occasional 3A  . 

 

[binky]

given shed is for fridge / freezer I would be wanting to use RCD exetrnal socket, and non-rcd protected socket for fridge and freezer or separate RCBOs and socket for each appliance / socket in shed.Nothng worse than coming home from holiday to find defrosted freezer

 

[Evans Electric]

Ah  I missed  the freezer bit ,   that would be better .