ProDave Problem, Lamp becomes live when CU switched Off!

[batty]

The job I did today was connected to a split load contactum with TD RCD main switch. The 30mA RCD is connected to the top of TD RCD so you could get caught out switching main switch off as the 30mA circuits will still be live. This is in a church hall. I think they need a bit of testing doing. I remember a while back somebody ringing about lights tripping out. I see somebody has upgraded breaker to a B16 and this is on a 1mm TW/E.

 

[batty]

Very true you cut corners to save time but it may be the last corner you cut.

 

[Joet1110]

Locking a isolator off is also very good practice.