Tt system/ time delay

[KNIPEX]

Guys can you just confirm please.im changing a db in a house which has a tt supply.

im putting in a dual rcd distboard 30ma on both sides and im going to split the circuits the correct way.

can you please confirm that tt no longer needs a time delay rcd upfront, and the reason why.

thanks

 

[Des 56]

No time delay required,because all circuits are 30 m/amp protected,the 100 m/amp s type would serve no purpose

There is suggestions about the need for RCD protection of supply tails of a metal clad board but not all insulated units