Called out to a job where a block of flats were without communal lights. Checked the consumer unit. MCB had tripped. When I reset it the lights turned on but some of the light fittings were buzzing loudly. These were mainly emergency back up light fittings. Replaced them. Turned the mcb on and the lights again came on. This time without any buzzing noise.
Later the same day I came back to fit another emergency light for the same block of flats ( I didn't have enough replacements). The MCB had tripped again. I reset it and turned the lights back on. No problem everything lit up. A few mins later when the lights automatically switch off the mcb tripped again.
I opened up the fuse board and checked the connections for the mcb fault. I found the earth was loosely attached to the earth bar. Reconnected and tightened it. Reset the breaker. Again a few mins later it trips again.
This time I connected the live to a spare 6A breaker. After a few mins it also tripped. So it's not a faulty breaker.
The block of flats contains 4 levels with 4 2D light fittings per level and a 500W PIR outside. Same as the adjacent bock of flats.
Any troubleshooting tips for this problem appreciated as I know I'll be there Monday am! >>
Later the same day I came back to fit another emergency light for the same block of flats ( I didn't have enough replacements). The MCB had tripped again. I reset it and turned the lights back on. No problem everything lit up. A few mins later when the lights automatically switch off the mcb tripped again.
I opened up the fuse board and checked the connections for the mcb fault. I found the earth was loosely attached to the earth bar. Reconnected and tightened it. Reset the breaker. Again a few mins later it trips again.
This time I connected the live to a spare 6A breaker. After a few mins it also tripped. So it's not a faulty breaker.
The block of flats contains 4 levels with 4 2D light fittings per level and a 500W PIR outside. Same as the adjacent bock of flats.
Any troubleshooting tips for this problem appreciated as I know I'll be there Monday am! >>
