two rings on one fuse?

[sm1thson]

are you allowed to have 2 rings on one fuse?(/MCB) the reson i ask is a friends house has his whole extension (kitched and bathroom) wired as a spur off the downstairs ring! (i have double checked and found the last socket on the spur and also the downstairs ring measures for continuity). His fusebox only has 4 fuses, and although a new CU would be best the need to make the kitchen a ring strikes me as been somewhat more urgent, -so can this be made into a ring back to the CU on the same fuse as the downstairs ring?

yes i know about part P.

 

[alphaalarms]

dont we all know about part p!!!!!

how many double sockets will there be if you had 2 rings into the same mcb?

its not good practic to have them on the same mcb! i tend to do 3 rings in a rewire (small house) upstairs, downstairs and the kitchen!

2 rings on 1 mcb is far better than spurs.../radials...

have you thought about a c/u upgrade

 

[sm1thson]

i rekon he has about 8-9 double sockets on the whole of downstairs inc kitchen (allthoug as i understand there is no set limit?), obviously doing this wont increase the loading and the fuse hasnt blown yet!. yep i know he should put a new CU in, but i expect it will be a case of kitchen first CU later, and doing it this way would allow the kitchen to be on its own breaker when a new CU is added!

i just want to make sure that the proposed plan does not break any regulations.

 

[Spark123]

It isn't a great plan, can you not install an additional consumer unit? Please remember sockets that can reasonably be expected to supply portable equipment outdoors need to be on an RCD too.

 

[sm1thson]

I know its not the best plan, but does it break any regulations? no point in adding an additional CU as may aswell just change the one thats there! -but untill then!

i gave him a lecture on RCD's and pointed out that his 'safety device' on his extension lead was for over heating (folowed by a lecture on fully unwinding the cable lol).

 

[Spark123]

Have a look at section 314

 

[Pensdown]

ditto the RCD.

In the short term you could make 1 ring by joining 2 of the legs together at the CU using crimps and putting the other 2 legs into the MCB.

IMO this is better than your proposal

 

[plugwash]

IMO this is better than your proposal

the only way in which it is better is being slighting more conventional and possiblly easier to get into the terminals.

in terms of volt drop, cable loading (which affects cable lifetime) and fault disconnect times its worse.

if it were me i'd stick them in one fuse for now but with a view to changing the CU in the future (and mark em up with some rings of tape so you know which ones which come CU change time).

 

[miajanjua]

IMO this is better than your proposal

the only way in which it is better is being slighting more conventional and possiblly easier to get into the terminals.

in terms of volt drop, cable loading (which affects cable lifetime) and fault disconnect times its worse.

if it were me i'd stick them in one fuse for now but with a view to changing the CU in the future (and mark em up with some rings of tape so you know which ones which come CU change time).

Read section 314-01-04, it will put you right

 

[sm1thson]

From what i can see i agree with plugwash. Somebody care to tell what it actually says in 314 (im not a spark and foot have a copy of the regs)

 

[plugwash]

Where an installation comrpises more than one final circuit, each final circuit shall be connected to a seperate way in a distribution board. The wiring of each final circuit shall be electricaly seperate from that of every other final circuit, so as to prevent the indirect energising of a final circuit intended to be isolated.

so the question then becomes do two rings on the same breaker count as two cuircuits or one unconventional cuircuit?

not that it really matters since until you get your new CU in your installation won't be compliant anyway.

 

[Pensdown]

Although there is nothing wrong with unconventional wiring I think 2 rings in 1 MCB is stretching section 314 a bit