Testing two CU's in one house

[Cirrus]

Quite a simple Q really - how would you go about testing an installation where you change the main CU but don't change the 'sub main' powering an extension. Also, I am changing the board to a 17th ed board - does the sub main 'automatically' need upgrading? At the moment it is fed via a 45A MCB (16mm t&e).

 

[Shakey]

Quite a simple Q really - how would you go about testing an installation where you change the main CU but don't change the 'sub main' powering an extension. Also, I am changing the board to a 17th ed board - does the sub main 'automatically' need upgrading? At the moment it is fed via a 45A MCB (16mm t&e).

Cirrus, you just test it as you would normally.

On the cet you put 'extent of installation covered by this certificate', and as long as that reflects what you have actually tested, then thats fine

 

[Cirrus]

'extent of installation covered by this certificate' - what does that actually mean though Shakey? Am I saying that I have tested everything in the house by puting that on? And are we saying I have to test the 2 boards or just the one I am changing?