Does your installation contain three RCDs in 'series' anywhere, have you had any issues with
discrimination amongst them?

There are several RCDs 'downstream' from the 100mA time delayed one
(but there are never three 'in series') :-

The 'split load' one in the outdoor CU protecting all sockets
outside and in garages.

The 'split load' one in the house CU protecting a couple of
circuits with sockets.

Two separate RCBOs on the 'non RCD' side of the house CU
protecting two ring circuits.

When these have tripped occasionally (for real faults in every case)
the 100mA time delayed one hasn't tripped.

Hi,

Thanks very much for that. Certainly sounds like nuisance trips shouldn't be a problem then.

Chris Key