I have recently replaced the PIR floodlight on the outside of my garage, as the sensor failed in the old unit.
The tail cable (3-core 1.0mm flex) from the light passes through a hole in the top of the door frame into the inside of the garage, where it is connected to the 1.0mm T&E cable from the controlling switch. The existing inline connector was very old and fiddly to work with, so I've replaced it with a Greenbrook 20A 3-way plug/socket connector in the hope that next time I need to replace the floodlight it will be a lot easier!
Before starting work I turned the switch off and pulled the fuse from the relevant circuit. After attaching the new Greenbrook to the T&E cable I got out my multi-meter to check everything before plugging in the new light. Earth continuity seemed OK. Putting the probes across L-E or N-E gave a 0V reading, as I expected. But for some odd reason probing across L-N yielded about 3.5V - why on earth should that happen?
The tail cable (3-core 1.0mm flex) from the light passes through a hole in the top of the door frame into the inside of the garage, where it is connected to the 1.0mm T&E cable from the controlling switch. The existing inline connector was very old and fiddly to work with, so I've replaced it with a Greenbrook 20A 3-way plug/socket connector in the hope that next time I need to replace the floodlight it will be a lot easier!
Before starting work I turned the switch off and pulled the fuse from the relevant circuit. After attaching the new Greenbrook to the T&E cable I got out my multi-meter to check everything before plugging in the new light. Earth continuity seemed OK. Putting the probes across L-E or N-E gave a 0V reading, as I expected. But for some odd reason probing across L-N yielded about 3.5V - why on earth should that happen?