New Consumer Unit

[trossachs]

I currently have a consumer unit which has no spare space for any extra circuits. I am in the process of upgrading my kitchen and will require a new circuit for the electric cooker. I also plan on converting my loft in the near future and will most likely put in extra circuits also. I am due to have a sparky come round and quote for the installation of a new unit and to run the new 30amp circuit to the kitchen.

What I wanted to know is what type of consumer unit should I be getting installed (to check the sparky is putting the right thing in)? Their is currently 3 lighting circuits and 3 ring mains for the sockets. I have heard about split units (which I dont think I currently have) what is the advantage of these? And what is the story of RCD isolations? Also is their anyhting else I should be asking when he comes round.

It would be great to have at least a small clue about what I am getting him to do, so I dont get a cowboy doing the job.

Thanks.

Jamie

 

[il78]

Split load board is the one you want....

Just tell the spark what you are intending to do in the future so that a decent size board can be installed. Socket outlets that are reasonably expected to be used to power equipment outdoors need to be protected by an RCD, If this RCD was to trip, your lights would remain energised (if splitload fitted). If the spark is going to change the board you should be asking for an Electrical Installation Certificate to cover the new board although this might lead to the spark giving you an extra quote to bring the rest of the installation to current wiring regulations (ie, Main equipotential bonding to gas/water might be undersized or not installed etc)

Let us know what happens....

Ian.

 

[ban-all-sheds]

Just to clarify - RCD - Residual Current Devices are designed to protect both equipment and users from fault currents between the live and earth conductors. They should be used in conjunction with fuses or MCBs which cannot detect this type of fault condition.

An RCD prevents fatal electric shocks by disconnecting the supply if the detected fault current exceeds a safe limit. Typically this is betwwen 30mA and 100mA. RCDs should always be used when equipment is being used outside, when there is a danger of cutting through the power cable, or when there is water present.

It is important to realise that an RCD does not detect over-currents or short circuits, and must therefore be used in conjunction with conventional protection devices.

An RCD protects either the entire CU, or just part of it if it's a split-load one, i.e. with a split-load board some of the circuits have RCD protection, and some do not.

Opinions vary as to whether you should or should not protect all of your circuits, and if you don't then which ones you should. The only ones that you must are sockets which could be used to supply stuff outside, so basically any on the ground floor, ot in a shed or garage etc. I think there are some that you mustn't, e.g. smoke alarms. Then there are others which are a good idea (eg all socket circuits - why not, electric showers etc), and others where, IMHO, it is not a good idea, e.g. lights, where the chances of a live-earth shock through you are very small, and where you really don't want the house plunged into darkness if the RCD trips, or fridge/freezers where you don't want to lose the contents if the RCD trips while you are out.

The cost of a larger split-load board compared to a smaller one, in the context of the overall cost of having it replaced is not huge, so I would strongly advise a bigger one than you think you need so that you can add more circuits in the future.

 

[Juno 60]

Quality advice and information, such as that given in this thread, are what makes this forum so good

 

[breezer]

to find out what an rcd is all about see this

 

[BR]

Also bear in mind that lighting, especially flurescent tends to 'leak' electricity causing nusience tripping of the RCD