You are reading a single comment by @Airhead and its replies.
Click here to read the full conversation.
-
The individual circuits Neutral and Earth are connected in a typical RCD setup. So touching Neutral and Earth with only the Live disconnected (i.e. single MCB switched off) will cause a parallel path to Earth from the Neutrals on the other circuits. This disrupts the balance in the RCD and trips it.
The current regulation is leaning towards RCBO's which protect each circuit individually, they are more expensive so they're not that popular with jobbing electricians who like to stay competitive on price and don't want the material costs eating into profits. They should be the future though, it's probably only a question of time before they're regulation.
Airhead
inchpincher
What indicates there's still power? Even if you've isolated a circuit then touch a neutral & earth it will trip the main RCD on the consumer unit (I think).