rcd strangeness..

[ColJack]

just took a surface socket off the wall at home to sink the backbox.
breaker was off, but when i took the neutrals out the RCD tripped as they seperated..

they didn't touch the earth or the bar across the top of the sockets, they were in free air and barely out of the terminal when I heard the rcd click off..

I know about N-E falt tripping but never known one to trip when just the neutral continuity is broken..

strange..

good job my uncle is changing the fuseboard for me
will be nice new Merlin Gerin board, with RCBO's all over it.. ( got lots of C32's left over from a job ( small flat, C's should be ok, will check EFLI before use.. ) just need to get 2 x B6's and a B45 for the shower..

 

[securespark]

Sure the breaker for that circuit was off?

 

[ColJack]

yup, tested live and tested dead..

 

[Spark123]

Did you check ring continuity?

 

[ColJack]

no, don't need to at this present time..
I'm only sinking a socket that was a surface socket, prior to tiling in my kitchen..

it has 2 cables into it, and will have 2 cables into it when I'm finished with it..

 

[Spark123]

Could be a borrowed neutral and combination of spur from spur or open circuit neutral. If there is anything this sinister then when you use RCBOs it will need to be rectified.
Could be as simple as the Live touched the backbox and leakage via an appliance exceeded 15mA>