wiring bathroom extractor with timer

[Corrado]

Am in the process of wiring a bathroom extractor (with timer). It says it is double insulated and needs no earth

This (like my shaver light) needs no earth. I have bought some 3 core wire from B&Q but one of the cores is an earth (Blue, Brown and Yellow/Green) - I am planning on wiring this into a junction box in the loft that the ceiling light and pull switch come from/into)

Brown wire into the continuous live (for the fan's timer)
Blue wire into neutral
Yellow/Green wire (now covered in tape to avoid confusion) into switched live.

Is this okay?

I think I have it all sussed but wanted to check if I can relabel the earth wire (as a switched live).

 

[breezer]

no its not ok, although you have marked it as not an earth, if some one should "cut into it" they will assume its an earth (since you can only mark each end) and.........

you can get 3 core and earth red, yellow and blue & of course earth which is meant for this purpose

 

[Corrado]

damn people at B&Q - they told me to go ahead and do this GRRR
thanks, though!
If I but the 3 core+ earth what do I do with the earth - do I connect it to the junction box earth and not the fan or neither as the fan says it doesnt need one?

Thanks so much for your help!

 

[plugwash]

hook it up in the junction box seal it off at the fan end (but best not to cut it off in case of future replacement of the fan with a double insulated one)

i've always used a peice of earth sleeving that extends beyond the core held on with a shar bend in the core to seal off the earth but i belive the niceic frown on this (i don't think the iee regs mention it directly but the regs contain a lot of general guidance that is very open to interpretation)

 

[Corrado]

looking at it - the junction boxes are old and all of the earths have been twisted together on the outside - looks like I will have a job twisting a new one on - should I really bother?

From the fan's instructions: "The fan is double insulated and does not require an earth connection."

 

[breezer]

yes you should, today you know there would be no earth, what about tomorrow?

 

[Corrado]

have just spoken to the manufacturer and they recommended that I should connect it up to a 3 core plus earth and not connect the earth at either end.

I anyone can see this being a problem, please let me know. I am using a 1mm flex and all cables are insulated - incl earth - so shall I cut them all to the same length and just not connect the earth or shall I trim the earth back down to the white outer insulation?

 

[breezer]

so you have 4 core flex? (3 + earth)

 

[Corrado]

I will use a 4 core flex

 

[breezer]

3 core and earth is easier to get, but to answer your question, put a choc bloc on the earth at the fan end since you may need it one day.

connect it to earth at the other

 

[Damocles]

It is a bad idea to have cables which include an earth which is not connected. Someone one day might use it as earth without testing it.

 

[Corrado]

just wondered how I go about connecting the insulated earth from a flex to my junction box, which has 3 earth cables already twisted together!
Suggestions? Should I clip the earth right back or shall I connect it somehow?

 

[plugwash]

agreed you should always hook the earth up at the supply end even if its not linked to anything at the load end

 

[Corrado]

how do I connect it at the junction box - twist on the other earths which are OUTSIDE the junction box?
Do I need a new junction box or am I creating too much work for myself?

 

[securespark]

The NIC recommend that ALL disused conductors should be connected to earth.