lighting fault

[bristollspark]

hi guys, advice needed as this problem is doing the old brain box in.
i was going to change a nasty fan light to a new nasty fan light in a customers house,found existing light still had the old ceiling rose above,with mains in and loop out to hallway light,and switch drop for lounge,all work fine,until i connected the wall lights in,switch in lounge is a 2 gang dimmer,when i switch on wall lights the mcb trips out !.

i have carried out an ir test,and results are fine.

responses are much appreciated.

 

[DurhamSparky]

where did you connect wall lights too..??

need bit more info...

possibly faulty dimmer??

 

[poirot]

How many wall lights and lamps, what rating is the dimmer?

 

[Deleted member 9648]

Can you explain a little more,you are changing a fan and then connect some wall lights in?,did you install the wall lights or are they existing?

 

[telectrix]

is it possible that you have confused a switched live with a neutral. easily done if they are not sleeved!

 

[poirot]

I take it that the I/R, continuity and polarity test were all fine before switching on?

 

[bristollspark]

hi steve,

dimmer is ok,changed it for a normal switch,wall lights are existing,not wired by me,connected neutral from wall lights in with neutrals from supply,and red from wall lights (switch live) in with switch live from switch,which i tested out to make sure it is the switch drop.i remade ends of conductors and all terminated in a jb.

 

[bristollspark]

hi,there are two wall lights,i could,nt tell you what rating of the dimmer is,havent checked to be honest,i have changed the dimmer to a normal switch to try it

 

[bristollspark]

hi, the wall lights are existing,not wired by me,i am basically changing the existing light with fan to a new one,i have reconnected all conductors in a jb,the neutral from wall lights is connected in with the neutrals from the supply and loop from hall light,and the switch live is connected in with the live from the wall lights.

 

[bristollspark]

hi, yea i did think that,because that is what happens,but i have metered them out to make sure,and when i disconnected the existing fan light i made sure i knew what was the switch lives.the red from the wall lights is connected in with the switch live (black with red sleeve)from the switch.and the black from lights is in with the blacks from the supply and hall light.

 

[bristollspark]

hi, yea tthe readings were all fine,the funny thing is they were workibg ok until i disconnected the old light,so it has to be a wrong connection somewhere,perhaps there is another jb in ceiling which is wired wrong to how it should be done,i love fault finding but this is stupid!

 

[adavis]

1)energy saving light bulbs? remove all the bulbs and switch on the power
2) I would take the wall lights off. switch on the power. and test the wires the the wall light positions to check the polarity is correct.

If the RCD is still tripping with the wall lights off you know it is the main fan/light

 

[Sintra]

I think you should be doing dead tests to prove polarity and continuity not live tests as you are suggesting.

 

[adavis]

your quite right sintra. you should really not do it live. very bad habit of mine.

 

[tenheads]

any tranny on the new fan light................poss type d mcb required? just a hunch!