Light just died

[SAB1]

Hi,

I am totally new to this site and am hoping someone can advise me as to the possible cause and steps to rectify the following?

I have a room with two wall lights both operated by two dimmer switches.

A few days ago when I switched on the lights, one light made a buzzing noise and then both went out. The fuse on the CU did not blow.

I have removed the switches and replaced both with just 1 gang 2 way switches, but now after rewiring, as soon as I replace the fuse in the CU and with both switches off the lights are on and each time I press the switch the fuse blows.

I have double checked the wiring to the switches, which was as the dimmers and the various wiring diagrams for two way switching on this site. I have also looked at the cables behind the light fittings which are the old colours but seem OK, no burning etc.

The wiring is as follows 1 wall light has 3 twin and earth cables. of which 3 reds connected together, 3 earths connected together and to earth on light fitting, 2 blacks connected together and connected to blue on light fitting and 1 black connected to brown on light fitting. On the opposing wall I have a single twin and earth correctly connected straight into light fitting.

Switch 1 has two cables twin and earth and 3 core and earth. red from T&E and red from 3 core connected to L1, black from T&E and black from 3 core connected to L2. Yellow from 3 core to common.

Switch 2 has a single 3 core & earth cable, red to L1, black to L2 and yellow to common.

I have tested both switches with a simple tester and I am getting 230volts at all three terminals in switch 1 with the switches in the off position and the light on, at switch 2 I am getting about 110volts!

Any suggestions, advice would be most welcome.

 

[PrenticeBoyofDerry]

//www.diynot.com/wiki/electrics:lighting:two_way_lighting
have look at this link and check it tallies up with your set up.
Remember colour changes about 4 years ago.
Red=Brown
Black=Blue
in your Twin and earth
and
Red=Brown
Black=Yellow
Blue=Grey
in three core and earth

 

[SAB1]

Hi Prenticeboy,

Thanks for reply, had checked against these and will check again.

Cheers

 

[JBPElectrics]

Now, I am usually wrong!!!!(at midnight after too much cider)

It sounds as though you have correctly wired everything.

Are you using a slave dimmer and a master dimmer?

If not they wont work!

CBW

 

[SAB1]

Hi CBW,

Thanks for reply.

Have already removed dimmers and replaced with 1g 2w switches.

Cheers

 

[flameport]

If you take all the lamps (light bulbs) out, does the fuse blow then?

 

[SAB1]

Hi Flameport,

Have removed lamps and fuse still blows!

Cheers

SAB1

 

[ban-all-sheds]

And you've made no changes to anything?

No new lights or new switches anywhere?

Done anything involving holes/screws/nails into walls/floors/ceilings?

 

[SAB1]

Hi,

I Didn't do anything, honest.

Cheers

SAB1

 

[PrenticeBoyofDerry]

check that all your terminals at both switch and fittings are tight and in correct terminals, and insulation of cables is sound, so no bare wires shorting inside fittings.

 

[mikhailfaradayski]

Can't help but think the problem is at wall light 1 and not the switches.

Hi,

The wiring is as follows 1 wall light has 3 twin and earth cables. of which 3 reds connected together, 3 earths connected together and to earth on light fitting, 2 blacks connected together and connected to blue on light fitting and 1 black connected to brown on light fitting. On the opposing wall I have a single twin and earth correctly connected straight into light fitting."]

The way that is connected, sounds like you have a permanent feed to wall light 2, a feed to the switch.
I might have suggested that it should be 2 reds connected together, two blacks connected together and connected to blue. 1 Black (which should also have been marked red) connected to 1 red and brown at the fitting.
It also sounds like the blacks have been mixed up.
Since the switch feed hasn't been marked from black to red, its anyones guess which black is which without a bit of technical twiddling

But if you have done nothing to the wall light at all since the last time you used them, im at a bit of a loss...

Picture time? lights and switches?

 

[SAB1]

Hi All,

Have now resolved my problem, found damaged cable in ceiling, replaced, all working.

Thanks to all respondents.

Cheers.

 

[ban-all-sheds]

How did it get damaged?

 

[mikhailfaradayski]

Hi All,

Have now resolved my problem, found damaged cable in ceiling, replaced, all working.

Thanks to all respondents.

Cheers.

seems i was off the mark then?

Which cable was damaged?

Do you still have the connections you originally described at wall light 1?

 

[PrenticeBoyofDerry]

Done anything involving holes/screws/nails into walls/floors/ceilings

Hi,

I Didn't do anything, honest.

Cheers

SAB1