Is this OK to do?

[NorthstaNder]

Hi,

Imagine a small bedroom, and a large bedroom seperated by a lathe and plaster wall.

In the small bedroom is 3 surface mounted double sockets. Put in by the previous owners electrian friend. The middle of the three has a cable coming up from the bottom of the socket box (so i'm presuming it's on a spur from another socket), and then that middle socket feeds the two other sockets, on the left and right of it.

I only need one double socket in that room and would like one on the other side of the wall in the larger bedroom and then I would get rid of the other third socket altogether.

So if I left the middle double socket where it is, could I get rid of one of them and then drill a hole through to the other side of the wall and move one of the socket boxes to the other wall? It would still be fed by the old middle socket, that's staying put.

Thanks in advance.

 

[securespark]

You need to investigate further. This middle socket, if only fed by a single cable, cannot feed two further ones unless it is a radial circuit.

 

[NorthstaNder]

Well, I don't know what kind of circuit we have to be honest. Is there a quick and easy way to tell?

Also, that middle socket will no longer feed two other double sockets, but just one.

 

[securespark]

The middle socket cannot feed anything except itself if it is a spur from a ring circuit.

What circuit breaker is protecting this circuit? Does the cable feeding that middle socket have solid core or stranded conductors?

If you trace that cable feeding the middle socket back to its origin, what do you find?

 

[hardbasta]

if the middle socket is a spur then it shouldnt feed 2 other sockets, the max load of a spur is 30A so 1 double socket = 2x13A (26A) so that is the max.
look in your consumer unit to see if the socket is on a ring (2 wires into 1 fuse) if it is it is more than likely a spur.
however, if you want to run 2 double sockets off it, replace the middle socket with a 13A fused spur, then run both sockets from that. it will work same was as a 4 scket adaptor then.

 

[GaryMo]

the max load of a spur is 30A so 1 double socket = 2x13A (26A) so that is the max.

30A?

 

[securespark]

if you want to run 2 double sockets off it, replace the middle socket with a 13A fused spur, then run both sockets from that. it will work same was as a 4 scket adaptor then.

A valid point which I would have come to soon enough.

if the middle socket is a spur then it shouldnt feed 2 other sockets, the max load of a spur is 30A so 1 double socket = 2x13A (26A) so that is the max.
look in your consumer unit to see if the socket is on a ring (2 wires into 1 fuse) if it is it is more than likely a spur.

Regulations say you can only wire one accessory onto a non-fused spur.

That is, 1 socket outlet or connection unit.

A single length of 2.5mm² cable (assuming that is what it is, and that is why I asked) can carry 27A maximum. However, socket outlets (even 2G ones) are only rated to 13A.

Finding two conductors on one fuse/cb is no guarantee of a ring. A better check (though not foolproof) for DIY'ers is to isolate the supply, find a socket with two cables, separate them, making them safe, then re-energise, testing with a two-pole tester to see if both "legs" are live.

 

[GaryMo]

However, socket outlets (even 2G ones) are only rated to 13A.

Not all....MK twin sockets are rated at 13A per outlet, 26A total.

Finding two conductors on one fuse/cb is no guarantee of a ring. A better check (though not foolproof) for DIY'ers is to isolate the supply, find a socket with two cables, separate them, making them safe, then re-energise, testing with a two-pole tester to see if both "legs" are live.

Or use a cheap multimeter on low resistance setting and check for basic continuity with supply isolated. Less likely to kill themselves!
Again, not a foolproof way of checking for ring continuity and correct connection of conductors.

 

[hardbasta]

A single length of 2.5mm² cable (assuming that is what it is, and that is why I asked) can carry 27A maximum. However, socket outlets (even 2G ones) are only rated to 13A.

i dont doubt u for 1 second, but as i understood it, the load was worked out by the maximum number of 13A fuses that could be plugged into a cable (I learn something new every day )

on the 2 wires into 1 fuse bit, i did say more than likely its a ring, so its safer to go the fused spur route than just hope that its a radial. from what ive seen, nothing with electrics can be taken for granted

 

[NorthstaNder]

hmmm...bit worried about all this now. what's the worst that could happen if say, all 4 sockets were in use and the power they were drawing was too much? would it just trip the circuit breaker?

oh...perhaps i should mention the room where the sockets are used to be the previous owners computer room which had his mac, printer, fax and goodness knows what else in it.

on the consumer board, there is a circuit breaker purely for that room's circuit as it protected all the computer gear. It appears to be seperate from all the rest of the upstairs wiring. It follows that the 3 (2 sockets if i go ahead with the change) sockets would be protected by that circuit breaker.

 

[GaryMo]

from what ive seen, nothing with electrics can be taken for granted

Nope, that's why there are professionals with expensive test equipment

 

[hardbasta]

hmmm...bit worried about all this now. what's the worst that could happen if say, all 4 sockets were in use and the power they were drawing was too much? would it just trip the circuit breaker?

it depends on the resistance of whats being used (im sure i'll get corrected again) afaik, the worst that can happen is the house burning down (am i right?) to be totally safe just put a fused spur & run your sockets from there.

Nope, that's why there are professionals with expensive test equipment

i will be soon, i allready have the expensive test equipment (fluke 1652)

 

[daytona]

hmmm...bit worried about all this now. what's the worst that could happen if say, all 4 sockets were in use and the power they were drawing was too much? would it just trip the circuit breaker?

if it works!

 

[NorthstaNder]

Just looked at the circuit breaker for that room...

It's a:-

Crabtree
40A RCCD (or B, I forgot in the time it took to get downstairs!)
30mA Circuit breaker

 

[securespark]

And no overcurrent protection?