RCD tripping on landing lights after new CU

[rob89]

hi recently changed a db, sll the upstairs lights work and so do the downstairs but as soon as i turn the landing light on it trips both rcds, how come and how do i overcome this and get everything back working, cheers

 

[Spark123]

Firstly, please do not hijack topics - it is better that you create your own topic for this.
From your description you'll likely find that the landing light takes it's live from the downstairs circuit and the neutral from the upstairs - often referred to as a borrowed neutral.
The only way to remidy it properly is to rewire the landing light so it is all on one circuit.
I take it you know about part p? Replacing a consumer unit is notifiable to your LABC.

 

[rob89]

sorry about hijacking i'm new to this site....

would a quick solution work if i changed the order of mcb so that the lighting circuits was on the same rcd side and off the same neutral bar

 

[AndyPRK]

A tempoary soluition is to put both lighting circuit MCB's on the same RCD. This will allow you to use the landing light.

However this does not meet the 17th edition as if the RCD tripped it would leave the house without any working lights.

 

[AndyPRK]

would a quick solution work if i changed the order of mcb so that the lighting circuits was on the same rcd side and off the same neutral bar

Yes

 

[rob89]

thanks alot guys i'll see what i can do

 

[sparkiedave]

don't ya just love the whizz-bang testing method?

 

[riveralt]

hi recently changed a db, sll the upstairs lights work and so do the downstairs but as soon as i turn the landing light on it trips both rcds, how come and how do i overcome this and get everything back working, cheers

I'd get the useless spark back who fitted your db and get him to fix it
I bet he never gave you a electrical installation certificate with the schedule of inspections and test results nor registered the work with the Local Authority Building Control.
If he cannot even recognise the problem of borrowed neutrals why the heck is he being employed to fit consumer units.