3 and earth

[con1_uk]

Yep I want to do it right but I need to make sure Im doing it right and safe.

Before I made any changes I noted where everything went and found out which cables supplied which lights and the main reason for my work is because I was fitting loft insulation to the area where the wires was and I read you cant put any insulation over any cables so I started work in moving the junction box to a non insulated area under the floor which will always be accessable in future.

When I first looked there was old types of wires like old flex going to one light so I replaced that with my 3 core and earth.

Also as I have mention before in other posts my upstairs lighting circuit dont have any earths so I can fit the fancy metal light fittings but the main supply for the junction box does have an earth cable fitted does this meen if I run new cables to the light points I can have metal lights?

How can I check if the earth is connected at the junction box end?

Thanks for your replys and patience so far.

 

[Maxxy]

If you've got a multimeter you could use that to test it. Realistically, when installing any new circuit you should be doing an Earth fault loop impedence test (EFLI) to ensure that you have got a good earth connection

 

[con1_uk]

So if the earth passes and it went from the incoming to the light and switch for that circuit then I can fit the metal fittings?


Thanks for the link to the diagrams I did have a look for them before posting it makes a lot more sense now but it says that the juction boxes have to remain accessable so is it ok to leave the junction boxes in the space I have left and run the new cables to the lights? My house is a mid terrace so its not that far to run.

 

[con1_uk]

Another thought.

What size should the cable be for the incoming power cable please?

 

[Maxxy]

So if the earth passes and it went from the incoming to the light and switch for that circuit then I can fit the metal fittings?

Yep. Providing its within the readings allowed by BS7671

What size should the cable be for the incoming power cable please?

Lighting is run in 1.5mm2 twin and earth

 

[con1_uk]

Looks like the same wire as a socket wire is this right?

Can it be too big?


So for instance if I put that cable into a new fuse at the CU and labled it Upstairs lights then I have got a nice new shiny circuit?

 

[Maxxy]

If your positive that its the same wire then theoretically yes you could put it into a new 6 amp circuit breaker, then fill out the necessary testing and inspection forms for a new circuit.

 

[con1_uk]

Think I will leave it on the same as the other lights then as it was.

Going out to buy some twin and earth to replace the 3 and earth then tonight and do it reet.

Also going to buy a new junction box and run my new room from that using the Wiki drawings.


Thanks for the replys and the patience.

 

[con1_uk]

Maybe a silly question but why do the junction boxes come in different load sizes? Is it because the actual place where you insert the wire is bigger for the thicker cable?

Just to confirm what cable size and junction boxes do I need for my setup please?

Thanks.

 

[Maxxy]

They come in different sizes because they have got different uses, eg ring finals (higher current) and lighting circuit (lower max current)

6A junction boxes, 6A fuse / circuit breaker and 1.5mm flat Twin and earth

 

[RF Lighting]

I generally use 20A joint boxes for lighting, as there is more room in them.

The current rating is the maximum current the JB can carry.

 

[con1_uk]

Right Im nearly there now.

My new light is in my main bedroom and I need to get the new cable to the light but the celling is plastered and the loft floor is down I can get access to the light through a hole in the roof but the void where the cable will travel has got rock wool in it, should I remove the insulation?

Thanks.