Newly Fitted 17th Edition Consumer Unit

[SPARTYKUS]

Would be a good idea to replace the 100a main switch on your CU for a 100a 100ma S type RCD main switch. Currently you are dependant on the 30ma RCD's for earth fault protection,a 100ma main switch gives back up if they fail to operate. That said the CU layout and Ze value you have complies with the regs for a TT earthing system.

Here we go with devils advocate

the above will help for sure but 100mA time delayed is not a life saver necessarily....why not just bung another 30mA RCD in series? Especially as they're 90% of the time all within a few inches of each other.... Isn't that "safer"?

apart from tripping over on the way to the fusebox becuase its snowing,dark,no candles, no torch, ........

 

[telectrix]

the 100mA RCD would be a back up fault protection device, not additional protection. for that you are relying on the 30mA devices.

 

[Midwest]

Are you accidentally pressing the button to test continuity....if you are you are nulling the leads to 0

I did exactly that with my 1730 recently, getting 0ohmms on continuity readings, really does throw you! I rang Megger technical thinking my tester had gone u/s. Really helpful person talked through problem, and you can 'over null' you tester. As the Megger 17 series will 'remember' your leads, it's a good idea just to test them each time you use them, or reset & null them. I still forget now.