I have an external security light, 500 watt halogen. It is one of the lights that comes on with movement but also has an internal switch. I recently had a new kitchen put in (the light is on the outside wall) and the room was rewired, they introduced an isolating switch and fuse. Ever since then the light packs up at regular intervals and I have to replace it. It has just gone again and I thought I would check the fuse before putting ladders up. The fuse is 13 amp they have put in, is that my problem? Is that letting too much electricity through, would have thought it should have been 5 amps?