Built in electrics for conservatory on new house build

[angeldust1]

I want to do the electrics for a conservatory I have just finished builing.

Our house is new and on the consumer unit we have a dedicated switch for 'Con supply' i.e. conservatory supply. Sure enough, by the patio door that goes through to the newly built conservatory, we have a blanking plate marked 'con supply'. This must have been put in by the builders in case you decide to put a conservatory in. I've had a look inside and we have single live, neutral and Earth cables going to a junction plate.

I would like to have 3 double sockets in the conservatory. My question is: Is there any reason I can't simply connect the 3 double sockets (one after the other) in a line to the 'con supply' junction box? i.e. 'con supply' junction box to socket 1, socket 1 to socket 2, then end at socket 3. Obviously I would need to drill a hole through to the inside of the house to begin the line.

The 'con supply' has it's own switch on the consumer unit. Thanks in advance for any help.

 

[Steve]

What size cable is it? What is the protective device? What distance from the fusebox to the conservatory (wiring)

 

[JACKC]

Agree with above. Need to know if you are fitting a ring final circuit or a radial. This will determine the advice given. Can you post a drawing of the positons of the consumer unit and the conservatory. I would now expect a picture of a turban wearing chap with a crystal ball to come from a regular poster. We need to know this as the cable size will be either 4mm or 2.5 mm depending on how you plan to install.

 

[angeldust1]

Thanks for your interest, any advice greatly appreciated. I'm not at home today and my knowledge is limited so I'll have to make some estimates.

I think the cable is 2.5mm.
Supply goes to MCB on consumer unit but I'll have to look what value it is when I get home.
Distance of consumer unit to conservatory is ~15 meters.
I am proposing a radial circuit.

 

[Chri5]

2.5mm TE as a 20A radial can run to a max distance of around 35m.

Please confirm fuse at board is 20A (or less), that the distance (for voltage drop) is no greater than 35m in total (last propossed socket) and that the design load of equipment will not exceed 20A.

 

[angeldust1]

Distance definately won't exceed 35m.
I'll have to check the rating on the MCB. How does the rating of the MCB relate to max distance for a given cable (here 2.5mm)? I'll have to look at the components but I'm not sure about design load for equipment. We are talking about a small domestic air conditioner, small LCD TV and possibly a lamp.

 

[Chri5]

2.5mm radial cannot take anything greater than 20A.

20a x 230v = 4600w, so you need to confirm that all potential equipment will not exceed the wattage mentioned.

Fine for lights, TV's and smaller appliances.

Big problem would be (eg) :- electric heating + iron + kettle + washing machine.

 

[ban-all-sheds]

How does the rating of the MCB relate to max distance for a given cable (here 2.5mm)?

Voltage drop http://www.tlc-direct.co.uk/Book/4.3.11.htm

& fault loop resistance : http://www.tlc-direct.co.uk/Book/5.3.1.htm

Read about how these affect cable sizes here: http://www.kevinboone.com/cableselection_web.pdf