RCD fuse box tripping out problem

[kevin_robson]

We had our house rewired last year and have an RCD circuit breaker box, with various switches in it for the various circuits.

Our washing machine is a bit iffy and occasionally trips the electric out, and will be replaced in the near future.

The thing that I am unsure of though is that when it trips out it trips the whole electricity supply for the whole house, whereas I would have expected it to trip out only the individual circuit. Is this correct?

The box seems to be split into a red half and a green half, and from memory it takes out one half, but I believe it leaves the lights (i.e. the other half) connected.

Can someone confirm whether the individual switch should trip, or whetehr it is correct that it takes out this much other stuff.

Thanks

 

[Adam_151]

You have whats known as a split load board, the RCD covers one half of the board

The small switches are MCBs which are a modern resetable equivelent to fuses, the RCD is something different, it protects against electric shock and is quite sensitive.

The use of a split load board is very much of a compromise, there is a actually 'reg' that says something like the installation should be devided up in such a way that shuould a fault occur, inconvienience is kept to a minimum, its kind of vague (maybe having the lights stay on meets this! ) and split boards are used for cost reasons, the alternative is to use a board without any rcd, and fit RCBOs (MCB and RCD in one unit) in place of some MCBs, unfortunatly these cost ~£40 each, and you have one per RCD protected circuit.

Think yourself lucky, before split boards became popular, it was not uncommon to have the whole board protected by an overall 30ma RCD...

The other problem with split boards is that some equipment leaks current to ground when there isn't a fault (computers etc) so you can have a situation where things nuisense trip due to all this adding up

 

[kevin_robson]

Thanks for clearing that up for me.
I was just a bit concerned the individual switches should be tripping out.
Sounds to be working as planned though.