Rating of RCD's

[KeenPensioner]

I am an adult learner. I understand the theory behind the 30mA trip rating (for example) of an RCD but I need some help understanding what the 63A rating (for example) actually means. My understanding is that RCD's do not provide over current protection, that would be provided by MCBs (for example) downstream of the RCD. Am I correct in saying that the 63A rating (for example) is the "switching" rating of the device rather than the current carrying capacity of the device? Any advice would be appreciated.

 

[James]

It is the maximum continuous current that can be passed through it.

it will be capable of disconnecting under full load but will not provide any over current protection

 

[KeenPensioner]

It is the maximum continuous current that can be passed through it.

it will be capable of disconnecting under full load but will not provide any over current protection

Thank you for your prompt reply. I watched a video from a well respected YouTube electrician (bigclive.com) and he was tearing down an RCD that was sent in by an electrician to see whether overload was the cause of failure. (View: https://www.youtube.com/watch?v=9wcPw5hUNpQ
) and he shows a picture of the CU that it was removed from. He also says that "..the 63A isn't a tripping current, it's the current it can handle on a continuous basis" (As you say above). I attach an image from the video and can't understand what an electrician would set up a CU with such high loads all (on a split board) 1 RCD. Any thoughts would be appreciated