I've got a mysterious nuisance trip problem on an RCD & wonder if anyone can help?
The light circuit isn't on the RCD, but about twice a week, the RCD is tripping when lights are switched. There is one main hallway light switch where it happens the most, but tonight it tripped when a bedroom light was switched on.
As far as I understand RCD's, a problem on this light circuit shouldn't activate the RCD. Or is my understanding faulty? Can a fault in a non RCD circuit cause an imbalance that affects the RCD anyway?
I was also testing the ground floor ring & got a 0.26 meg-ohms reading on a 250 volt insulation resistance test. After checking all the outlets for faults, I came to the boiler which is spurred off the ring main. When the boiler was isolated, I got a 2.2 meg-ohms reading. But when the boiler was switched on, back to the 0.26 reading. So I suspected there was something up with the boiler, but when I tested the boiler wires independantly of the spur, I got a 99 meg ohms reading. So I assumed I had a faulty spur & replaced it. But I was back to square one though. Testing the boiler shows no fault, testing the circuit with the boiler switched off gives me a very good reading, but testing the ciruit with the boiler on gives me a bad reading.
Do you have any tips and do you think the 0.26 reading is an indication that the circuit could trip at anytime and that therefore even though the light is off the RCD, that light switching could alter the balance enough on the boiler circuit to cause the RCD to trip?
I'm trying to determine whether I should investigate the boiler more, or investigate the light or other circuits more. It's a 5 bed house, so lots of places to check.
Thanks
The light circuit isn't on the RCD, but about twice a week, the RCD is tripping when lights are switched. There is one main hallway light switch where it happens the most, but tonight it tripped when a bedroom light was switched on.
As far as I understand RCD's, a problem on this light circuit shouldn't activate the RCD. Or is my understanding faulty? Can a fault in a non RCD circuit cause an imbalance that affects the RCD anyway?
I was also testing the ground floor ring & got a 0.26 meg-ohms reading on a 250 volt insulation resistance test. After checking all the outlets for faults, I came to the boiler which is spurred off the ring main. When the boiler was isolated, I got a 2.2 meg-ohms reading. But when the boiler was switched on, back to the 0.26 reading. So I suspected there was something up with the boiler, but when I tested the boiler wires independantly of the spur, I got a 99 meg ohms reading. So I assumed I had a faulty spur & replaced it. But I was back to square one though. Testing the boiler shows no fault, testing the circuit with the boiler switched off gives me a very good reading, but testing the ciruit with the boiler on gives me a bad reading.
Do you have any tips and do you think the 0.26 reading is an indication that the circuit could trip at anytime and that therefore even though the light is off the RCD, that light switching could alter the balance enough on the boiler circuit to cause the RCD to trip?
I'm trying to determine whether I should investigate the boiler more, or investigate the light or other circuits more. It's a 5 bed house, so lots of places to check.
Thanks