s type rcd main switch

[Simon-0116]

How do you verify its an s type, owner says previouse electrican fitted time delay 100ma rcd main switch,. All I can see is it says 0.1, which id 100ma, 125a rating. Do some have adjustable time, or what is the time delay range of s s type thanks

 

[JD6400]

It will normally have an s inside of a square stamped on it .
Or just give it a test and see what It goes out at .

 

[Simon-0116]

300 ms x 1 at the rcd?

 

[JD6400]

I would expect closer to 400ms personally .