Lighting Problem

[hazbart]

I have a light in my hall which up until recently was working fine.

It is controlled by two switches, one at the top of the stairs and one at the bottom. The switch at the bottom of the stairs is a triple switch which controls 2 other lights which are working fine.

The switch at the triple switch seemed to be the master switch as if it was switched to off the single switch wouldnt turn the light on, if the triple switch was on you could switch the light on and off with the single switch.

Now it wont come on at all regardless on how the switches are set.

I recently changed the pendant in the dining room to a hallogen spot light and as a result replaced a ceiling rose with junction box, I dont think this has affected it as they are on different circuits.

I took the single switch off to reveal 2 red wires, one connected to com and the other to L1, and 2 black wires, neither of which were connected. Thinking I had found my fault I connected one of the black wires to L2, but nothing, so I tried the other, nothing and eventually I tried both connected to L2 but again nothing, seems as though there is no power to the switch, checked it with volt stick and nothing seems to be flowing to it.

Any suggestions?

 

[luminaire]

Depends how it is wired, but if those two black wires are in fact neutral wires then the last thing you want to do is to connect them to the switch.

If all has been working correctly previously, then it's best not to alter the wiring but find the fault.

Maybe, when doing the lounge wiring one one might be loose. It's best to check the JB and make sure it's correctly wired.

Failing that some pics of the wiring might help, at both switches and your JB.

 

[hazbart]

Depends how it is wired, but if those two black wires are in fact neutral wires then the last thing you want to do is to connect them to the switch.

If all has been working correctly previously, then it's best not to alter the wiring but find the fault.

Maybe, when doing the lounge wiring one one might be loose. It's best to check the JB and make sure it's correctly wired.

Failing that some pics of the wiring might help, at both switches and your JB.

The JB that I fitted is on another circuit though, surely there couldnt be a connection there?

 

[luminaire]

Is not your dining room and hallway on the downstairs lighting circuit?

 

[hazbart]

Is not your dining room and hallway on the downstairs lighting circuit?

No.

I stay in a flat.

2 Lighting circuits.

 

[luminaire]

In order to switch the hall light on from the top and bottom of the stairs you need two -way switching. For that you need to have a 3-core cable connecting between the two switches. Normally, red, blue and yellow.
Now if you haven't got that, then I really don't know how they could have operated especially if you haven't distubed the switch on the landing.

Can you get a pic of the switches?

See here

 

[hazbart]

This is the switch at the top of the stairs, very hard to take a pic of the other switch as the cable is very tight.

No yellow cable in either switch.

Been up in the loft and the whole wiring is a bit messy, about 7 sets of cables all connected through terminal blocks, I can identify which wires are which, was considering replacing the block with a JB to see if that helped.

I also recently changed the light fitting in the living room which is on the same circuit as the fault. Its working fine but I'm wondering if thats got something to do with it.

There was no ceiling rose to change, just the actual light fitting, but thats the only change to this circuit.

 

[luminaire]

Hazbart, to see what it should look like have a look at the Wiki . This is what I was talking about.

Now if it's nothing like that and by what you're telling me that it doesn't have ceiling rose or junction boxes, then I'm guessing it wasn't wired up originally by an electrician. It may mean that you'll need to get an electrician in to sort it out, because you definitely need 3-core and earth to connect the two switches and it does sound as though the wiring is in a bit of a mess.

 

[Space cat]

From your description of how it worked when it did work, you didn't have two-way switching. There isn't a master switch in a two-way switching circuit; both switches are equal and either can turn the light on or off. Those extra cores in the upstairs switch are suspicious. You can do two-way switching without a three core and earth cable between the switches. You use two core to connect the L1's and L2's together. It's an old fashioned method but it does work - and it sounds like you have all the right wires in place. I strongly suspect that it worked until one of those black wires fell out of L2!

Question 1: Have you removed any wires from any of the three downstairs switches?

Question 2: Do the other two lights on that triple switch still work?

Question 3: Is the non-functioning light on a different circuit to the other two?

 

[hazbart]

From your description of how it worked when it did work, you didn't have two-way switching. There isn't a master switch in a two-way switching circuit; both switches are equal and either can turn the light on or off. Those extra cores in the upstairs switch are suspicious. You can do two-way switching without a three core and earth cable between the switches. You use two core to connect the L1's and L2's together. It's an old fashioned method but it does work - and it sounds like you have all the right wires in place. I strongly suspect that it worked until one of those black wires fell out of L2!

Question 1: Have you removed any wires from any of the three downstairs switches?

Question 2: Do the other two lights on that triple switch still work?

Question 3: Is the non-functioning light on a different circuit to the other two?

Spacecat,

Q1, No, downstairs switch hasnot been touched until I opened it yesterday to check the connections which were all fine.

Q2, Yes both the other lights on the triple switch work.

Q3, No, we have 2 lighting circuits, its def on the same as the other two and the lounge light.

I'm still convinced it has something to do with the lounge light we fitted, although there was no ceiling rose it seems odd as most of the other lights in the flat have CR's and since we changed it the hall light stopped working.

 

[Anteaus]

First point to realise is that on lighting, a black wire need not necessarily be neutral, it may be a switched live. You're supposed to indicate this with tape or sleeving, but cowboys don't bother. Therefore, make no assumptions.

In general the best way to sort-out a tangle like this is to buy a cheap multimeter and do continuity checks with the power off. Only when you understand what goes where can you begin to trace the fault.

Incidentally, you can have a 'three-way' switch controlling one light, to do this you need to break the lines between the two-way switched, and fit a double-pole changeover switch such that it reverses the two connections.

http://www.ultimatehandyman.co.uk/three_way_lighting.htm

 

[Space cat]

I recently changed the pendant in the dining room to a hallogen spot light and as a result replaced a ceiling rose with junction box

and

I'm still convinced it has something to do with the lounge light we fitted, although there was no ceiling rose

I can't make sense of those two statements. Was there a ceiling rose or not?

With any fault, the last thing you did is certainly a good place to start, even if they appear completely unrelated. In your case you seem to have no power on any wire in the upstairs switch. Take a close look at the wires in the downstairs switch, specifically those in the one for the non-functioning light. My guess is that you'll find three wires, one in each terminal and the ones in L1 and L2 will belong to the same cable. I will also stick my neck out and predict that the other end of that cable is in the upper switch with its red core in L1 and its black one dangling loose. Examine that loose black carefully for signs that it was once under a grub screw in L2.

If I'm right, you once had a two way lighting circuit. The L's were linked like for like and the only unknown is which COM was permanent live and which one still goes to the light. The absence of a permanent live supply takes us back to that ceiling rose. Check that you got all the wires into the terminals. How many reds are in the same terminal and how many blacks in a different one. The total number of wires coming out of the ceiling to the box should be a multiple of three. Are they all actually connected? It's easy to tighten a grub screw onto insulation instead of bare copper - at least it is until you get to know the feel of it through your screwdriver. Take a close look.

 

[hazbart]

I recently changed the pendant in the dining room to a hallogen spot light and as a result replaced a ceiling rose with junction box

and

I'm still convinced it has something to do with the lounge light we fitted, although there was no ceiling rose

I can't make sense of those two statements. Was there a ceiling rose or not?

With any fault, the last thing you did is certainly a good place to start, even if they appear completely unrelated. In your case you seem to have no power on any wire in the upstairs switch. Take a close look at the wires in the downstairs switch, specifically those in the one for the non-functioning light. My guess is that you'll find three wires, one in each terminal and the ones in L1 and L2 will belong to the same cable. I will also stick my neck out and predict that the other end of that cable is in the upper switch with its red core in L1 and its black one dangling loose. Examine that loose black carefully for signs that it was once under a grub screw in L2.

If I'm right, you once had a two way lighting circuit. The L's were linked like for like and the only unknown is which COM was permanent live and which one still goes to the light. The absence of a permanent live supply takes us back to that ceiling rose. Check that you got all the wires into the terminals. How many reds are in the same terminal and how many blacks in a different one. The total number of wires coming out of the ceiling to the box should be a multiple of three. Are they all actually connected? It's easy to tighten a grub screw onto insulation instead of bare copper - at least it is until you get to know the feel of it through your screwdriver. Take a close look.

Space cat,

Quite simple really.

I replace 2 lights, one in DINING ROOM and one in Lounge!! The dining room had a ceiling rose the loung didnt. They are on different circuits though.

 

[hazbart]

Update.....

I have disconnected all the wiring on this circuit and have now reconnected most of it an have the Hall light working from the upstairs switch only and the stair light working from the triple switch only.

Think it has been badly wired for starters but now I have at least got two lights working, although not the way I want.

Think it may be time to call in an expert to finish the job though, I cant for the life of me figure out how it was wired originally, so any chance of me getting full functionability back on my own are slim.

I've connected the wires back in but seem as though I'm missing something as no matter how hard I try I cant get power to my outside light which was previously operated on the triple switch, or get the stair light to switch off or on using the upsatirs switch.

Almost ready to give up.

 

[Space cat]

I have disconnected all the wiring on this circuit and have now reconnected most of it an have the Hall light working from the upstairs switch only and the stair light working from the triple switch only.

Hazbart, you give up too easily. I need to clarify a few things:

1) You live upstairs so the hall light is upstairs and the stair light is downstairs.

2) The triple switch is downstairs.

3) The hall light once worked from both switches, though not in a true 2-way fashion.

I'm unsure on that last point because of this:

or get the stair light to switch off or on using the upsatirs switch

When you say you disconnected all the wiring, does that include all the wires in the switches or just the ones in the terminal blocks? Do you still have two black wires dangling loose in the single switch?

PS: Sorry about the confusion over lounge and dining room lights. I didn't read the earlier posts properly.