Wiring shower fan light

[DIYLadette]

Hi, Just bought a new shower fan light and even with the wiring diagram, i'm a bit confused (i'm new to this). Someone help please!!

The story is I'm replacing the old light with some spotlights (sorted i can do that), addingg in a junction box(can do that too) and fitting a new switch for the fan light (that too-yippee). No earth is required but the timer fan needs L, N and SL, while the light needs just N and SL.

Ithought 4 way junction box: 1)power in 2)power out 3) cable to fan (L,N)4) cable to switch (L,N) then from switch to lite (N, SL) and switch to fan(N, SL). But now i have 2 N's for the fan? I may be blonde but can these be wired together or am i being really stupid? and is 2 core flex the right one to use?

Ta
DIY ladette

 

[breezer]

if you have 2 neutrals left for the fan then you must have gone wrong some where.

try the for refernce section, except instead of "to next light", yours will be "to fan"

 

[ban-all-sheds]

Neutral does not go to the switch, just live and switched live.

 

[dingbat]

Ithought 4 way junction box: 1)power in 2)power out 3) cable to fan (L,N)4) cable to switch (L,N) then from switch to lite (N, SL) and switch to fan(N, SL). But now i have 2 N's for the fan? I may be blonde but can these be wired together or am i being really stupid? and is 2 core flex the right one to use?

Ta
DIY ladette

Junction box:
Terminal 1: Live in, live out, live to switch and permanent live to fan.
Terminal 2: Neutral in, neutral out, neutral to light, neutral to fan.
Terminal 3: Live return from switch (switched live), switched live to light, switched live to fan
Terminal 4: All circuit protective conductors. (with green/yellow sleeving over bare conductors.

(Live out and neutral out, by the way, refer to rest of the lighting circuit beyond this point. If this is the last point on the circuit, however, there will ony be live and neutral in - see breezer's diagrams in the 'for reference' post)

I'm guessing here that you're existing wiring is red and black plus bare earth. If you can still get hold of the old colours then you should ideally use twin red and earth for the switch cable, but red and black can be used provided you use red sleeving or tape on the black at each end, as this is being used as a live conductor and not neutral in this instance.

The fan needs three-core and earth; if you are using old colours (red, yellow, blue) then red is your permanent live, yellow your switched live and blue, neutral. This cable should go from the junction box to the fan via a three-pole isolating switch, so that you can isolate the fan for maintenance without having to isolate the whole lighting circuit. (If you can only get cable in the new colours then brown takes the place of red, blue replaces black and the 3-core + earth will be red>brown, yellow>grey and blue>black... I'm sure you'll figure it out!)

 

[pipme]

Of course there is the matter of the required fuse for the fan.
Which, when 3 amp, is less than the 'lighting' fuse.
I guess this should protect both SL and L to fan .... Done to death elsewhere in this forum, still a challenge to the amature having 3+E cable and a Fused Connection Unit with L(protected): N : E : supply and load connections only.

Ok sorry everyone ....

P

 

[breezer]

don't need fcu if fan on lighting cct, yes some manufactures say you mus, but not all

 

[securespark]

Neutral does not go to the switch, just live and switched live.

Unless it is a triple pole iso....

 

[DIYLadette]

Thanks for these replies everyone .

Glad there are so many of you out there willing to help.

Fingers crossed for this weekend then (i did mean switch live and live to the switch but the colour is what i class neutral with a silly red sleeve on it)

Ciao until the next cry for DIY help.

 

[DIYLadette]

Having read your replies in detail, it is all so clear to me now.

Descriptions in words are far more helpful than the pathetic tiny wiring diagram provided and my mixing up of N and SL cos of the wire colour.
(is being blonde a valid excuse?)

Thanks again - Success now beckons!!!!!!

 

[breezer]

may i suggest you read 7th post down here (by ban-all-sheds)

 

[DIYLadette]

Cheers Breezer,

I at least understand electricity flows, have had success with multiple sets of spotlights, additional sockets in the ring main, shaver sockets and dimmer switches with the diagrams provided but for some reason this one stumped me

I was obviously having a blonde moment because I have now drawn a diagram that i understand, compared it with the original and surprisingly enough, they are the same! again