Was asked to look at this job today where the lights on a 6a mcb wouldn't reset. I turned up watched the the person onsite reset the mcb where it instantly reset with a bang and arcing coming from it. I did it again, same thing happened. So i turned all the light switches off and reset the mcb and it held in so i thought great so i switched each switch on one by one expecting the circuit to blow which it didn't and it held in so turned the mcb of and on again and it held in. I then did an insulation test LN-E about 140ohms bit lower than what i was expecting as was a new circuit roughly 8 years old i'd guess. There was 2 out side fittings on this circuit so i looked in them thinking there could be some water inside after the heavy rain we've had both bone dry and no signs of damage ZS 1.04 which was what i was expecting. I Then decided that i would open up all 8 light fittings in the corridor and in every light all the ballasts seemed fine no slightly nicked cables which i could see. But i did change 2 2D lamps which where looking very black and proberly about to die. The only thing i did find wrong was that the emergency lights where wired wrong. when you turned the key switch off the switch live remained live instead of killing all power to the fittings as it should do.
i have no idea where do go from here. Maybe disconnect every fitting and do an insulation test bewteen live and neutral, but im thinking this will be clear as the mcb isn't popping. any ideas what may be happening?
i have no idea where do go from here. Maybe disconnect every fitting and do an insulation test bewteen live and neutral, but im thinking this will be clear as the mcb isn't popping. any ideas what may be happening?
