RCD question

[barnetboy]

This is my first post so be gentle on me.

My downstairs ring is protected with a 30mA RCCB on the CU. The socket nearest my front door, the one I use when trimming the hedge, etc, is a 30mA RCD socket.

Is there any advantage in this belt & braces approach and which one would trip first if there was a problem?

Many thanks in advance.

Paul.

 

[davy_owen_88]

They would probably trip at the same time (unless one is time delayed, but it shouldn't be). There is no advantage in having 2x similar 30mA RCD's protecting the same circuit.