Adding new sockets into a room

[Wend23]

Hello can anyone help? I have one double socket in a bedroom but would like to add about 4 new double sockets. I am placing them into the wall and under floor boards, but can anyone tell me if I have to use a loop system? Or can I just used a junction box of the main socket to serve all the other sockets

 

[ban-all-sheds]

Is the existing circuit a ring final, or radial?

It's most likely to be the former, in which case, you may not spur 4 sockets unless you use a fused connection unit. Would it not be easy to extend the ring?

Is the circuit RCD protected?

//www.diynot.com/wiki/electrics:walls

And don't put sockets under floorboards.

 

[PrenticeBoyofDerry]

I have one double socket in a bedroom but would like to add about 4 new double sockets. I am placing them into the wall and under floor boards

I assume it is the cable that is being routed underfloor rather than socket outlets?

but can anyone tell me if I have to use a loop system? Or can I just used a junction box of the main socket to serve all the other sockets

I would steer away from using junction boxes and the standard junction box is no longer allowed in areas that can not be accessed for maintenance, inspection and testing purposes.

The way you extend the circuit would depend on the type of circuit you have.

Ring final circuit would need extending in a way that keeps the loop/ring continuous and loaded evenly and if you dio spur sockets, you can only spur one outlet from any one socket on the true ring. The radial is a little more flexible and allows for extending spurs of multiple sockets.

You can also use a fuse connection unit rated at 13A, from any one socket on the true ring and then add as many spurred sockets as you like from that fused spur, but this will only allow for 13A total load on the additional sockets.

Then you must consider the addition of 30mA RCD protection for any newly buried cable and all new socket outlets, it maybe that this protection already exists on your system and this circuit, but would need confirming.

You must also route cables within the permitted safe ones and use the desired techniques that comply to building regs when chasing cables and holing joists.
There is plenty of information in Wiki in Electrics section.
//www.diynot.com/wiki/Electrics:index

One of the most important things that is very often overlooked by the DIYer, is that the circuit and any addition to it will require proving it is safe before it is re-commissioned, this will require using the correct inspection and testing procedures and calibrated testing equipment. This would also require to be documented in the form of a certificate.

 

[ericmark]

And don't put sockets under floorboards.

Why not? It has always made me smile you have to mount at a silly hight on the wall but there is nothing to stop you fitting in the floor which is very common in offices.

For DIY the easy way is often the use of a RCD FCU to supply sockets because of the fact most DIY people don't have the equipment or knowledge to test.

But with test equipment then as long as within the limits for volt drop and loop impedance then extending the ring is a better job.

A ring final is nearly always protected by a 30A fuse or a 32A MCB/RCBO. However a radial could be 16, 20, or 32 amp the latter would use thicker cable than used with ring likely 4mm² or 6mm² so first step has to be finding out what you already have.

So with a 16 or 20 amp fuse/MCB/RCBO very likely a radial so extending is easy. With a 30 amp fuse or 32A MCB/RCBO you will need to test before you start.

It is near impossible to fit RCD protection to a ring final anywhere other than at the consumer unit so since all new sockets need RCD protection then if RCD protection not already fitted only real option is to use RCD FCU to supply new sockets.

Yes you could use Ali-tube cable and RCD sockets but once you look at cost I am sure you will use RCD FCU.

But before going any further you need to give some more information.

* Is it a ring your coming from?
* Is it already RCD protected?
* Are you really floor mounting sockets?

 

[ban-all-sheds]

And don't put sockets under floorboards.

Why not? It has always made me smile you have to mount at a silly hight on the wall but there is nothing to stop you fitting in the floor which is very common in offices.

"Under the floor boards" is not the same as "in floor boxes".

But before going any further you need to give some more information.

* Is it a ring your coming from?
* Is it already RCD protected?
* Are you really floor mounting sockets?

Indeed.