by Dave From Leeds »
Fri Dec 14, 2012 1:58 am
Two of the three wiring ports in your new fitting should be connected to the two pins of the actual lamp holder that the bulb contact. The third one shouldn't be connected to anything. You need to establish which two ports go to the lamp holder and MAKE CERTAIN that the other one isn't connected to the metal sleeve of the lamp holder (if it has one) or anything else in the fitting for that matter. If you can't do that I'd get an electrician to connect it up for you. If you ARE able to establish all that, then connect the black from the switch to one side of the bulb holder and the two blacks twisted together to the other side. Fix the three reds into the remaining port that isn't connected to anything.
As I stated above, if you're in any doubt whatsoever about which two ports connect to the bulb holder or, perhaps more importantly, that the other port isn't connected anywhere else in the fitting DO NOT tackle this yourself. The three reds are all live, as is the single black wire from the switch when it's turned on. The other two black wires are the neutrals coming from the consumer unit and onto the next light in the circuit. Both the live and neutral wires are known as "line" wires as they form part of the circuit during normal operation of electrical equipment whereas earth wires, where there are any, do not.