Electric wiring help pls

DIYhelp76

Hi
Hope someone can help. I have a pull cord switch which isn't working and needs to be replaced. I did my own one a while back and it was straightforward - it was in the ceiling and the only three wires there were earth, live and neutral. It was a straightforward like for like switch.  Now I am trying to fix one for an elderly relative where the cord is also not working. It is in a loft area. I opened it but it has many more wires. I'll try to post a picture.  It it has one main cable going into the cord switch and then another cable which leaves the cord switch, runs along the rafters up to the actual light with bulb.  

Each of these cables has earth, live and neutral.  But the two live wires (browns, from each cable) are both wired into the cord switch, one in COM and the other in L!.  Then the two neutrals (blues) (from each cable) are both set into one of those terminal connector block things.  The two earths are correct in the terminal box of the cord switch.

I haven't seen one like this before, where the two lives go into the cord switch and the two neutrals are terminated in a connector block.  

I can just replicate what is there, but as we haven't used this light in the loft before, I wanted to check if what is there seems correct. Please can anyone comment?  

I will to to post a photo

DIYhelp76

Here is photo

rob7475

That looks normal to me but I'm no spark so don't take my word for it. Usually, any neutral wires aren't connected to the switch and just go into a joining block. Only live cables go into the switch and the switch controls the 'live' supply to the light. Occasionally you'll see blue wires go into a switch terminal but they are usually live rather than neutral and should have brown sleeving over them.

FreeBear

Just replicate what you have there with the new switch.

Section62

DIYhelp76 said:

Hi
Hope someone can help. I have a pull cord switch which isn't working and needs to be replaced. I did my own one a while back and it was straightforward - it was in the ceiling and the only three wires there were earth, live and neutral. It was a straightforward like for like switch.

That would be incredibly unusual for a working lightswitch, unless the switch was integral to a luminaire.

More likely the 'blue' wire was being used as one of the 'live' wires.  It should have had brown sleeving on it to indicate this.

DIYhelp76 said:

Each of these cables has earth, live and neutral.  But the two live wires (browns, from each cable) are both wired into the cord switch, one in COM and the other in L!.  Then the two neutrals (blues) (from each cable) are both set into one of those terminal connector block things.  The two earths are correct in the terminal box of the cord switch.

I haven't seen one like this before, where the two lives go into the cord switch and the two neutrals are terminated in a connector block.  

I can just replicate what is there, but as we haven't used this light in the loft before, I wanted to check if what is there seems correct. Please can anyone comment?  

The wiring in picture is correct if one cable is correctly connected to the supply, and the other cable goes to a luminaire.  The two blue wires - if being used as a neutral - pass through the switch fitting (without being electrically connected to the switch itself) to provide the neutral connection to the luminaire.

mi-key

That is all correct. The switch breaks the brown ( live ) feed to the light itself, the other wires just pass through from the wiring before the switch on to the light. 

ROY47

That would be incredibly unusual for a working lightswitch, unless the switch was integral to a luminaire.

More likely the 'blue' wire was being used as one of the 'live' wires.  It should have had brown sleeving on it to indicate this.

Not these days please don't confuse the issue

The correct answer is

That is all correct. The switch breaks the brown ( live ) feed to the light itself, the other wires just pass through from the wiring before the switch on to the light. 

 

Section62

ROY47 said:

That would be incredibly unusual for a working lightswitch, unless the switch was integral to a luminaire.

More likely the 'blue' wire was being used as one of the 'live' wires.  It should have had brown sleeving on it to indicate this.

Not these days please don't confuse the issue

The correct answer is

That is all correct. The switch breaks the brown ( live ) feed to the light itself, the other wires just pass through from the wiring before the switch on to the light. 

The OP said "I did my own one a while back and it was straightforward - it was in the ceiling and the only three wires there were earth, live and neutral."

If a switch is wired with one cable which has two conductors (in addition to earth/CPC) then neither of them should be a neutral.

Wiring a light switch across 'live' and neutral is a very bad idea.

If a switch is wired with a cable with one blue and one brown conductor then what should be done "these days" differently to what I said?

FFHillbilly

You are both getting mixed up.

the OP incorrectly called the switched live a neutral 

Sectio62 pointed out that it's not a neutral

the picture posted is the current light switch, not the one discussed above

it looks fine by the way, just wire the new switch exactly the same

Section62

FFHillbilly said:

You are both getting mixed up.

the OP incorrectly called the switched live a neutral 

Sectio62 pointed out that it's not a neutral

the picture posted is the current light switch, not the one discussed above

it looks fine by the way, just wire the new switch exactly the same

I'm not mixed up.  I separated the OP's post into two parts when I quoted it.  I replied about the first light switch the OP worked in in the first part of my reply, then about the second (present) light switch in the second part.

The key point is for the OP to appreciate in the first case (the one most commonly found in older houses) the black or blue wire shouldn't (normally) be a neutral.  The second case (probably) does have a neutral present because it represents a fundamentally different wiring method to the first.

FFHillbilly

based on the description below I'd say the pictured switch has a neutral, no "probably" about it
DIYhelp76 said:

It it has one main cable going into the cord switch and then another cable which leaves the cord switch, runs along the rafters up to the actual light with bulb.