Im trying to get my head around the CU requirements for a TT system. If i was to fit a CU with RCBO's protecting all the circuits, would the main CU switch 100A or 63A need to be a time delayed RCD or could it just be a straight forward isolator switch as the RCD protection is provided by the individual circuits RCBO's.
The current set up is 3036 rewirables with a voltage operated earth leakage type D isolator switch between the main fuse and the CU.
So would i need an RCD isolator between the main and the CU then a main switch in the CU which is a time delayed RCD then to individual circuit RCBO's.
Seems an awful lot of RCD type protection and i still have a single failure point in two places.
I am aware this is all notifiable but i am at my planning stage.
The current set up is 3036 rewirables with a voltage operated earth leakage type D isolator switch between the main fuse and the CU.
So would i need an RCD isolator between the main and the CU then a main switch in the CU which is a time delayed RCD then to individual circuit RCBO's.
Seems an awful lot of RCD type protection and i still have a single failure point in two places.
I am aware this is all notifiable but i am at my planning stage.