CU for TT

[liam b]

just a quicky

If the wiring for a TT installation is not in metal conduit is it right that a normal split board with two 30mA rcds can be used? Ze of 21 ohms

cheers

 

[malcolmsanford]

With the advent of the 17th and now 99% of all circuits in a domestic situation having to be RCD protected it's becoming less defined the difference between TT and TN earthing systems.

Yes you can use your 30mA split board for TT now, I would still prefer to use non-metal clad board for TT as well.

Ze 21ohm excellent.

 

[liam b]

Just checking i didnt need a 100 mA time delay. Thanks

 

[malcolmsanford]

For a domestic installation complying with the 17th Edition where all the final circuits are RCD-protected, an RCD main switch is no longer required, provided that the consumer unit is of all insulated construction.

 

[ezzzekiel]

or rcbo to each circuit