CU to conservatory

[hinders]

Hi, I am planning running wiring from my Cu to my conservatory, the consumer unit inside are 3 spare 16 amp breakers would it be ok to wire straight into these with one length of 2.5mm twin an earth? I am planning on running a TV/ps3/freeview box probably a lamp as well but in winter on accasion a 2kw electric fan heater.

 

[Chri5]

2.5mm radial can take 20 amp so 16 amp isn't a problem.

Do consider that 17th ed requires circuit to be rcd protected and even if it didn't you should protect the conservatory circuit since there's a very good likehood that you may run something outside off a socket.

 

[hinders]

2.5mm radial can take 20 amp so 16 amp isn't a problem.

Do consider that 17th ed requires circuit to be rcd protected and even if it didn't you should protect the conservatory circuit since there's a very good likehood that you may run something outside off a socket.

thanks , yes one of the breakers is on the rcd side and this was the one I will be using. It was just a thought that the 2.5 might get hot with a fan heater running off it, I can still use 4mm if this would be more suitable for the job.

 

[1john]

can you let us know how the cable will be ran, in trunking, in insulation, in a boxing with central heating pipes ect?

Normally though 16A MCB on 2.5 is more than adequate. If you had room you could install two radials, that way you can have a designated circuit for the heater which dependent on how you install the cable and how the heater is connected to it doesn't need to be on the RCD side.

 

[hinders]

Yea, i was going round the top inside the cavity and leaving just enough mortar out to pass the cable through the wall. The sockets are sitting just under the sill. the heater is a 13amp plug.

 

[ban-all-sheds]

//www.diynot.com/wiki/electrics:part-p

 

[Chri5]

Yea, i was going round the top inside the cavity and leaving just enough mortar out to pass the cable through the wall. The sockets are sitting just under the sill. the heater is a 13amp plug.

What load is it in watt / kw ? divide by 230 = amps.

If you think the circuit load will be high then a 4mm radial might support a 32 amp mcb subject to distance of circuit from cu and installation method.
However from what you have said this is unlikely due to insulation and necessary cable derating. Without my books to hand I'd guess that derating will restrict a 4mm to about 26 amp load, so a 20 amp mcb could be supported by a 4mm cable.

As mentioned it might be best to run 2 x radials 2.5mm with one covering the heater only- or join them up and have a ring.

 

[LoveRocket]

A single 2.5mm radial on 16a MCB is absolutely perfect for what you describe. A 2kW heater will take about 8.5amps, the rest of your stuff will draw next to f-all.

Good job.