Guru
Joined: 05/10/2019
Location: United KingdomPosts: 7435
| Posted: 02:57pm 17 Jun 2024 |
AFAIK We could do this, but the supply from an external source has to have local isolation before you can access the terminals without a tool. If a tool is necessary (e.g. a screwdriver) then only an isolator and warning notice are required, without an interlock. There also has to be a label by the mains switch informing that there is an external supply coming into the premises that isn't controlled by that switch. This is because firemen isolate the building supply at that point.
Of course, the incoming external supply can only be accessible in a sensible zone. Not a bathroom or somewhere like that.
Mains supplies are actually a major problem in the UK. The incoming mains supplies traditionally have only the supply fuse as a means of isolation. However, it is illegal for anyone but the supply authority to pull that fuse. Hence, whenever an electrician needs to work on a consumer unit his only means of isolation is the built-in switch. Replacing a consumer unit means either getting the supply authority to pull the fuse (which they charge for) or break the law and pull it anyway. Luckily most of the meter companies will now install an isolator after the meter, but some still want to charge a lot of money to do so.