Hologen lights working-New Ceiling-Lights no longer work!

[Northbeach]

I have 5 halogen downlights low voltage 20w (not the most popular lights around here!) on a transformer connected via dimmer switch in my living room. I've recently placed a new ceiling up via plasterboards (though have yet to skim).
This morning I recut the holes where the original spots lay and placed the 5 spots back in.
Unfortunately, when I hit the dimmer switch to turn the lights back on I didn't get anything...bar one spot which seems to 'wimper' irrespective of the level the dimmer is turned to. Aside from adding the ceiling absolutely nothing has changed with this set up.
I flicked the fuse box off and checked the light fitting; bit of an old set up but it had the black cable with red tape (live) in one slot, the earth connected to the back plate and then a red cable (common) and a grey shielded cable (with what looks like 2/3 copper cores tiwsted together...my very basic understanding appears to leave me flummoxed over what this cable is for??) going into the other available slot (should that be right???). It appeared that one of these cables had slightly come out so I placed it back in and tried again...nothing.

Wondering what the likely causes are here:

*Dimmer knackered (switch was used despite lights not being placed back in for a couple of weeks...missus has a bad memory!).

*Faulty transformer (as I've installed a new ceiling I'll have to try and pull up the floorboards in the bedroom above).

*The cables in the light switch not wired up correctly...I'm half thinking the 'grey sheild copper core tiwsted' cable shouldn't be in the same slot as the red cable??

Bit of a panic as we have guests up this weekend...and we'll have one dark living room (though we do have lamps fortunately...).

Cheers.[/code]

 

[Northbeach]

Ok...I think I may have isolated the problem, though not the cause.
I have switched the dimmer used in the kitchen with exactly the same set up (5x 20w Low Volt halogens) into the living room and still no light...can't be a faulty dimmer then.
I did notice more prominently this time that the first light on the circuit directly after the transformer lights up ever so slightly; the second one even less so, though lamps 3,4 and 5 do get the 'juice'.
Mate brought up a voltmeter at the weekend and although we tested both the swtich socket (fine) and the lamp connectors (not really able to fully test these) we could'nt get to the transformer at the time.
Am I right in thinking that I can pick up another Low Volt transformer and wire this back into the loop?
I can only assume that the vibrations from the drilling of the plasterboards into the joists somehow knocked the transformer somewhat...are they known as being delicate?

Cheers.

 

[Northbeach]

Don't think this thread's going to win any end of year awards!
Sorry to keep dragging this half cut donkey up but...HELP! I'm really struggling to source what's going wrong with this lighting;
I've just replaced the Low Volt 105va (for 5 x 20w lamps) transformer with a new one (looked better built than the one supplied with the halogens).
I go to turn the lights on and....the first (bright), second (mid bright) and third (low) lights come on - four and five are dead.

So I'm getting a better supply from the new transformer but the problem remains the same. I've run a non contact volt tester along the ceiling where I know the cables to run - it lights up on the whole run.
The only thing I can think of is as I'd run the cables from underneath originally (under the joists then back into the ceiling cavity) that the new plasterboard fixed to the ceiling have 'squeezed' the life out of the cables....or I'd inadvertantly drilled a dry wall screw into joists 'chafing' the halogen cables as I've done so.

Are there any other likely causes or further tests I could carry out (I have multimeter - will travel)?!?

Many thanks.

 

[didthathurt]

Can you elaborate on what light fitting you are talking about with the 3 cables. How old do you reckon your electrical system is? How are your lights connected, is it by choc blocks, say, or crimps or what?

 

[Northbeach]

Yes - the 5x low volt halogens are connected via a choc block (older cables isolated and blocked and taped up).
Pretty old system - red live cable/black with red tape switched live and earth cables across the house (which is handy as I've started replacing the old wall mounted switches with sunk chrome types).
I have only one lighting circuit which runs upstairs and downstairs.
However on this one switch (1 way/gang), and I only noticed this at the weekend, the switch is connected as follows:

Switched live (black with red tape)
Live (red cable)
Earth
and...grey sleeve cable containing red cable which has several (three - 90% sure from memory) copper cores wound together and has been placed into the same slot (L1?) as the live cable. Myself and a friend (telecoms guy not leccy...unfortunately!) adapted the cables as such:
Took out the grey sleeved red cable cores out of the switch then tried the light again - aside from the living room lights in question not working, the hall lights stopped working also (is this some kind of odd feed from them?). The hall lights set up is - one downstairs and two upstairs on a two way/gang dimmer (though the upstairs one is also reponsible for the bathroom lights - which were working).

Since I took out the lamps when I placed the ceiling up the only thing that has changed is:
* I'm fairly often refitting the light cables on the switches in the hall lights - somehow they work themselves out loose. The lower hall 2 gang dimmer I refitted on this occasion (the upstairs lights wouldn't turn on though the lower one would)...wasn't entirely sure if one cable went in correctly...they still work most of the time, though I occasionally have to flick the light on from upstairs rather than down.
*secondly I added a new light to the system - replaced an old screw in shade type (and moved it centrally in the bedroom) with a 4 bar halogen strip (mains 50w). Is it possible I now have to many lights on one circuit (though they're always to dimmer to around half brightness at most)?

I'll also add that since nipping out this evening that small bit of power going to 3 of the 5 spots has 'evacuated' and no power at all is getting to them

^^ That sounds like a right waffle - soz folks! Might it be an idea to post an image or two? Failing that, call Derek Acorah?
Cheers.

 

[securespark]

Need pix!

 

[didthathurt]

Gordon Bennett!

That grey sleeved jobber is, from your description, the live feed to that part of the lighting radial that serves the hall. It sounds like your system has witnessed a level of expansion since it was installed.

The system you describe sounds about 40+ years old as I take it there is no earth wire in the cables. Do those "chrome" plates have an earth terminal and how have you connected those? When you say earth cables across the house, do you mean multi strand twisted unsheathed earth cables? If so, that's nearly Time Team dating evidence - others may hazard a guess at the age of those.

From my reading of your description it may well have been expanded a bulb too far in an unsympathetic manner, it sounds like there are a great number of screw connections all over the place which could be reducing the available power (a volt tester shows volts - it's amps that light the bulbs - a voltage across a very high resistance is still a voltage even though a negligible current will flow and poor connections = high resistance). It can be the case that wires that persistently loosen in a sound fitting do so due to repeated thermal stress!

It, frankly, sounds like one of those when my heart sinks after I walk in and open up the first few fittings as I know how hard it can be to unravel a cats cradle of wires. Unless there is a spark of inspiration out there in cyberspace ( ) I think you may well need someone to go hands on to sort that little lot out. Sorry.

 

[Northbeach]

Ok!
I'll get em posted tomorrow....I've heard of phantom power in audio but never in lighting...somethings sapping their energy

any possible thoughts so far?
I really do like the light they throw out (when dimmed a little however) but I can see why you lot stear well clear of them. If it were humanly possible I would've vaulted my whole ceiling through my back window by now!
Thanks.

 

[Northbeach]

Gordon Bennett!

That grey sleeved jobber is, from your description, the live feed to that part of the lighting radial that serves the hall. It sounds like your system has witnessed a level of expansion since it was installed.

The system you describe sounds about 40+ years old as I take it there is no earth wire in the cables. Do those "chrome" plates have an earth terminal and how have you connected those? When you say earth cables across the house, do you mean multi strand twisted unsheathed earth cables? If so, that's nearly Time Team dating evidence - others may hazard a guess at the age of those.

From my reading of your description it may well have been expanded a bulb too far in an unsympathetic manner, it sounds like there are a great number of screw connections all over the place which could be reducing the available power (a volt tester shows volts - it's amps that light the bulbs - a voltage across a very high resistance is still a voltage even though a negligible current will flow and poor connections = high resistance). It can be the case that wires that persistently loosen in a sound fitting do so due to repeated thermal stress!

It, frankly, sounds like one of those when my heart sinks after I walk in and open up the first few fittings as I know how hard it can be to unravel a cats cradle of wires. Unless there is a spark of inspiration out there in cyberspace ( ) I think you may well need someone to go hands on to sort that little lot out. Sorry.

Hi Didthat...sorry I probably didn't make it clear - all the light switches have earth cables in them - Red Live - Black with Red Band Sw/Live - Green Sleeved earth cable (all the chrome switches have a new earth feed to the back plate).

The wiring in the ceiling 'roses' looks pretty old (hence isolating certain cables as no longer needed) but having earth in the light socket feeds and a fairly newish (10 yrs +) fuse box suggests a refurb once (the house must be 60 years old at least).
The 'screws all over the place' - as in new light fittings etc?
As for the amount of lamps - here is what I have:

5 x 20w l/volt Hal in the kitchen
5 x 20w Hal l/volt in the living room (the poorly ones in question)
1 x 50w Hal in the lower hall
2 x 20w hal l/volt upstairs hall
2 x 20w Hal l/volt in the bathroom
Bedrooms: 1: halogen rack 2 x 50w mains
2: hal rack 4 x 50w mains
3: hal rack 4 s 50w mains

Yup - it's a house of halogens! But even with all the other lights off the living room ceiling one's aren't having any of it.
Looks like I'll be sticking fairy lights on the ceiling this christmas then (rush is I'd wanted it all finished before then)!
Many thanks.

 

[Northbeach]

Now have pics (which hopefully will post up ok):
Nothing really changed since I put the ceiling up - the lighting set up remains the same. Slight feeling that the feed from the hall lights might be partially responsible...the top hall light sometimes refuses to turn on (of flickers) - if you take off the switch plate then this light stops working - appears that the feed wire is a little loose (too short by the looks of it...when I finally sink this into the wall I should have a little more to play with) - the same wire which feeds into the living room lights (as you'll hopefully see on the pics).

I'll try and explain as best I can here folks (bit of a jumbled mess here and the camera doesn't really pick the details up too well):

OK:
* This is the original ceiling rose connections now fed into the halogens via the transformer - the old red and earth cables have been chock blocked and taped up) the live and neutrals being fed into the L and N of the transformer:

*Living room light switch (dimmer). Switched Live into Common and Live and feed from hall (grey sleeved over red & 3 core copper wire)

*The lights in question!!

*This is the feisty 2 gang/way hall light (dimmer again).
Top view: Red/Black/Loop (grey sleeve with red and copper cores - feeding the living room lights) - this is then looped onto the lower section of the dimmer - the lower hall light)

*Bottom View: one wire is the loop from the top section (for the upper hall light) the other is a grey sleeved red 3 core cable - fed from/to upstairs?)

Not sure if this lot is a hinderance more than anything...
Possible these lights are on a series set up? I'm sure I've replaced bulbs which were not working yet the others continued to (in the same set up in the kitchen).

Cheers.

 

[Steve]

the first pic - this alarms me. no junction box? You need one. Could be a loose wire here.

lights in series? lol. sorry. just doesnt happen. ever. except xmas lights.

and i would have torn down the lath and plaster while i had the chance. im surprised the downlights fit through the laths and the board.

 

[securespark]

Are the kitchen lights 2 way?

Do you have a dimmer at BOTH ends?

 

[ricicle]

Need pix!

Bet you're glad you asked now

 

[Northbeach]

Ahem...where do I start!!

the first pic - this alarms me. no junction box? You need one. Could be a loose wire here.

lights in series? lol. sorry. just doesnt happen. ever. except xmas lights.

and i would have torn down the lath and plaster while i had the chance. im surprised the downlights fit through the laths and the board.

The first pic (that's not an ice cream by the way!) - I can certainly add a junction box, in fact I was going to ask whether this might be a wise move. The previous set up here was to strip out the old ceiling rose and add a 4 way stip spotlight set, I've now used the same Live and Neutral but in this 5 x halogen spot set up...lol - most of this work is via advice from an old leccy mate of mine...there'll be words this xmas!

Parrallel/Series - Aye - I've had bulbs blow whilst the rest run fine...just a suggestion which flew my way.
I wish I had ripped out the lathe now, but constraints meant I had to overboard the lot...the spots go in after a squeeze.

Are the kitchen lights 2 way?

Do you have a dimmer at BOTH ends?

Sorry - no. The kitchen has exactly the same set up (light kit/dimmer switch) as the living room but are one way. The hall lights are two way - one switch a double dimmer, the other normal double switch...which means I can't have the bathroom lights on a dimmer (self tanning that room), but that's a whole new query which I won't burdon you lot with!
The dimmer switch and transformer are both buzzing (barely audible mind) when the light is switched on...and this set up was working fine before the new ceiling went up...it's a darned mystery.
I can get hold of a junction box tomorrow if this is a good first point of call?
Thanks for the replys folks, I'll understand if this thread ends quivering like a mashed up wreck in the corner, but it's a bit puzzling eh?

Cheers.

 

[Northbeach]

Hi all - sorry to drag this one back from the depths...

I left this over the busy xmas period but have now attempted to 'put it to bed' for a final time.

Crafty - I unwrangled the messy wires as seen in that hideous pic and placed them in a junction box (20amp), the 'out of use' wires isolated within that and the live and neutral (live and switched live) ready to connect to the live and neutral on lighting. I assume that Junction Boxes can be used for isolating certain cables rather than choc block and tape method?
I've also got rid of the transformer and purchased mains halogens (5x50w).
The original wiring from the LV 20 watt lights unfortunately remains plastered into the ceiling and I don't want to mess around rechisseling this out from below I've pulled the floorboards up from above. They're no longer connected to anything so I'll cut them back and the bits under the cable (plastered under the joists) will remain there for good (can't see any problems with this?).

Quick question (which will quite possibly be another daft question!) on the rewiring of these new lights - as cable wasn't included with the lights (unlike with the LV kits which contained the black L&N cables) the paperwork advises 1.0mm core cable. I have plenty of this cable but it contains an unsheathed earth cable: as I won't require this can I just clip this off at the grey sleeve on both ends (leaving just the blue/brown)? Are there any possible issues with this being in there (these lights don't need earthing unlike say metal stip halogen lights)?

Many thanks.