Sockets tripping different rccb?

[Adam Paj Paget]

Quick question which I will probably kick my self when I look into the d/b in the morning.
We currently have a house being restored(finishing touches) had western power out this morning to change over to PME, I came home from work popped in the house to catch the first half of the rugby and put the kettle on.
On the split rcd board down stairs ring and upstairs lights on one rcd, with downstairs lights on the other rcd all running fine until I turned the kettle on which tripped out the rcd with only the downstairs lights on any ideas of what I might be missing by the sockets on the other rcd making it trip with the kettle?
All advice welcome (and laughs)

 

[Lucien Nunes]

Can you confirm that all the outgoing neutrals have been disconnected from the neutral bar on the RCD that trips...

 

[Octopus]

Update
With all circuits isolated on 1rcd, kettle still trips out the rcd with no circuits on.

Any chance you could confirm the tests done on the RCD and circuits?

 

[Adam Paj Paget]

Found the fault gas hob brand new with internal fault

 

[Richard Burns]

Switching off the MCB will not affect the fault as it is on the neutral that is not switched off.
You need to find the fault on the lighting circuit and testing of the circuit will do that for you, to some extent.

Little diagram to clarify (or mess up) your approach


EDIT: Just too late fault is found, typical!!:sick:

 

[MisterE]

But a nice picture anyway :smile5: - Thanks