SNAP. About a year ago I was called to a similar problem. The owners were going through about 30 – 40 lamps per month. I went through all the usual stuff of suggesting better quality lamps, but they had already done that and it didn’t work so they went back to the el cheepo B&Q lamps, I tested the circuit, tested the neutrals etc etc etc checked the voltage time and time again on each occasion it was fine. Anyway I ended up fitting a voltage recorder and leaving it for 2 weeks. When I looked at the results it showed regular voltage dips to around 138 and peaks to around 275. After a lot of messing around I discovered there was a sewage pumping station around 50 meters away and when the pump started and stopped the voltage dipped them peaked when it stopped. Problem found…but still not sorted.
Ian
