I have recently wired a light fixture with 4 halegen spots in the bedroom. All works fine until you turn off the lights at the switch at on the wall at which point the main circuit trips. Does anyone have any idea why this might be and more importantly how I fix it?????
Since only trips when you switch off this not so easy to work out what you have done. So start with questions. Can you reset trip with lights off or do you need to leave on all the time? What type of trip goes out MCB or earth leakage (latter has trip test button)? What is the result if you remove the bulbs?
I will guess at possible scenario that you have connected new lights to live feed on ceiling rose and the light switch across live and neutral and switch is upside down so when you say switch off really you are switching on.
I will guess you have got the black wires mixed up. Please look at projects page and see how they are wired and then come back and give some more information. Main thing are you really sure you are switching off?
sounds like you have connected the wires wrong when you did it.
Check that all the reds(live) probally 3 are together, that the in-coming black (neutral) is contact with the out going black (neutral) to blue side (neutral) of light and the black switch wire (which should have red tag or sleeve on it) is connected to brown (live) side of light.
all earths connected together
If your wiring is new harmonized colours, Reds=Browns, Blacks=Blues
If it's end of loop there will be no out going neutral or live but wire as above but without them included.
Best of Luck,
Remember be safe and always safely isolate the circuit you are working on.