Can anyone help? I have tried to replace a very old ceiling rose in a hall with one light and a switch at either end of the hall. I have 2Red and 2 black wires and a new fitting marked L-LOOP-N. I wired the two red wires which were twisted together into the L connecter, and a single black wire into two seperate N connecters. When I switched the power back on it tripped the switch WHAT HAVE I DONE WRONG THANKS Ann ( PS Koshka is my cat.)