See the attached image.
I have been sent to a building that is about 15 years old. It has recent had its Communal consumer unit changed and since then the communal Lights have been having issues with tripping the RCD. It is a shared RCD but for testing I have disconnected all conductrs of other circuits. So it is the only circuit on the RCD. I have ramp tested the RCD and it trips at 27mA. It's a 30mA so all good there.
I am assuming the lights weren't RCD protected before.
There are 24 of these fittings on the circuit and they are switched with a Staircase timer setup, though I have removed the timer to test and the results are the same. 12 of the fittings are in the communal areas of the 4 storey block and each of the 12 appartments in the block have 1 fitting in it's own respsective entrance hall. I have only managed access to view 4 of the appartments fitting and all those are non-emergency. So it looks like there are 8 emergency and the rest are non-emergency.
The issue is this. If the circuit has been dead for a while, when you first turn the lights on, the RCD trips. Flick the RCD back on and the lights will work. If the lights are only on for say, 30 seconds, there doesn't seem to be an issue. If they are on for over a few minutes, when they turn off the RCD will intermitently trip. Turn it all back on and same again. Works fine if on for a short time, can trip if been on a while. or will trip if been off for a while.
I have inspected all the fittings I can get access to and other than the original installer using black for neutral on new colours, they seem fine. I have checked the CU end an all matches up so it isn't the conductor use that causes the issue.
It has been completely bending my melon today. With it being intermitent, you can think you are making progress whilst breaking the circuit down and seeing how much you can energise and then a random trip.
In a final ditch attempt to make any sort of progress, I have disconnected all the conductors from the emergency style fittings, parked up the emergency feed in a connector block and then put the switched feed and the neutrals into a pendant. I cycled the timer 6 times before leaving for home and the circuit held the hole time. If the circuit holds throught the night with tenants using it through the evening I will have hopefully narrowed it down to either an emergency fitting being faulty or a cummulative issue with all the emergency fittings. I don't know enough about these fittings to know if they have leakage and if they do, would they be enough to trip a 30mA RCD???
The mobile reception at the building is terrible though I did manage to get the data sheet up for the emergency controller and it states they have 0.5mA leakage. I assume this is the type of leakage an RCD could detect???
I have fitted loads of these fittings in the past, but none protected by an RCD (all environments that reg didn't dictate RCD required at the time) so don't know if they have a inherent characteristical issue.
Anyone got a clue what the issue could be as my head is hurting???
Thanks
I have been sent to a building that is about 15 years old. It has recent had its Communal consumer unit changed and since then the communal Lights have been having issues with tripping the RCD. It is a shared RCD but for testing I have disconnected all conductrs of other circuits. So it is the only circuit on the RCD. I have ramp tested the RCD and it trips at 27mA. It's a 30mA so all good there.
I am assuming the lights weren't RCD protected before.
There are 24 of these fittings on the circuit and they are switched with a Staircase timer setup, though I have removed the timer to test and the results are the same. 12 of the fittings are in the communal areas of the 4 storey block and each of the 12 appartments in the block have 1 fitting in it's own respsective entrance hall. I have only managed access to view 4 of the appartments fitting and all those are non-emergency. So it looks like there are 8 emergency and the rest are non-emergency.
The issue is this. If the circuit has been dead for a while, when you first turn the lights on, the RCD trips. Flick the RCD back on and the lights will work. If the lights are only on for say, 30 seconds, there doesn't seem to be an issue. If they are on for over a few minutes, when they turn off the RCD will intermitently trip. Turn it all back on and same again. Works fine if on for a short time, can trip if been on a while. or will trip if been off for a while.
I have inspected all the fittings I can get access to and other than the original installer using black for neutral on new colours, they seem fine. I have checked the CU end an all matches up so it isn't the conductor use that causes the issue.
It has been completely bending my melon today. With it being intermitent, you can think you are making progress whilst breaking the circuit down and seeing how much you can energise and then a random trip.
In a final ditch attempt to make any sort of progress, I have disconnected all the conductors from the emergency style fittings, parked up the emergency feed in a connector block and then put the switched feed and the neutrals into a pendant. I cycled the timer 6 times before leaving for home and the circuit held the hole time. If the circuit holds throught the night with tenants using it through the evening I will have hopefully narrowed it down to either an emergency fitting being faulty or a cummulative issue with all the emergency fittings. I don't know enough about these fittings to know if they have leakage and if they do, would they be enough to trip a 30mA RCD???
The mobile reception at the building is terrible though I did manage to get the data sheet up for the emergency controller and it states they have 0.5mA leakage. I assume this is the type of leakage an RCD could detect???
I have fitted loads of these fittings in the past, but none protected by an RCD (all environments that reg didn't dictate RCD required at the time) so don't know if they have a inherent characteristical issue.
Anyone got a clue what the issue could be as my head is hurting???
Thanks
