Fusebox being fed by a ring main

[Crazyk]

Hi guys

turned up to a residential property today to add a few double socket outlets only to find the fuse box in the area was being fed by a ring main on the main switch. Is this allowed ?

 

[micknew]

diyer.................

 

[Marvo]

So there's a main CU supplying a socket ring main which in turn supplies another fuse box....is that correct? What is the fuse box supplying?

 

[Crazyk]

3 rcbos ( 16amp with 2 double sockets 1x20amp feeding 3 double sockets, 1x6amp feeding 6 6watt led spots

 

[micknew]

Perhaps he intends doing the fuse box addition tomorrow, just checking if its acceptable lol.

 

[Crazyk]

No this is existing, I am checking if its acceptable

 

[Marvo]

I'm confused, when he said 'fusebox' I imagined fuses. I really don't understand the layout....

 

[ExArmy]

are you an electrician?

 

[Crazyk]

Main fuse box then off of this goes to another fuse box using a ring main as a sub mains

 

[Crazyk]

Surveyor

 

[ExArmy]

well whats the ring thats feeds it fused at? it probably doesn't break any regs, but is liable to be overloaded and trip the MCB feeding the ring and DB.
is it an actual ring main , with sockets, or is it just a sub main wired up with 2 x 2.5mm conductors?

 

[Crazyk]

It feeds 4 other double sockets as well and fused at main DB at 32Amps

 

[Crazyk]

Apparently been like this for 4years

 

[ExArmy]

well these proposed new sockets could be the straw(s) that breaks the camels back!

 

[Richard Burns]

This is likely to work but not to be suitable for installation. The possibilities for overloading a cable are very real. However in normal use a socket circuit does not draw much power.
A ring final can only have a spur limited to 13A or a single double socket attached to it.
Effectively this is creating a very high current draw potential at a single point, which is not the intention for a ring final.

 

[Crazyk]

Thanks

 

[Guitarist]

There was a thread about something similar a few months back. It's quite common to find garage boards fed by a 2.5mm RFC (I've come across a few myself), on installs carried out during the 70's, as this was seen as a cheaper alternative to 6mm on a 30 amp fuse.
Obviously, in this case, the RFC is straight off the main switch which is very naughty.

 

[telectrix]

but this scenario appears that someone has tapped into a RFC to feed a sub-main. not good, IMO.

 

[stranded]

I'm confused, when he said 'fusebox' I imagined fuses. I really don't understand the layout....

Havent a clue... I imagined fcu's....

 

[Guitarist]

but this scenario appears that someone has tapped into a RFC to feed a sub-main. not good, IMO.

I read it as an RFC straight off the main switch of the original board to feed the sub-board. Happy to stand corrected though.