On 23/10/2013 23:27, bm wrote:
On 23/10/2013 22:50, Bill wrote:
Hi all, especially the knowledgeable electricians on here.

What are your thoughts on me replacing all of the MCBs in my CU with
RCBOs? At present I have 14 MCBs all protected by one 30mA RCD main
switch. Over the last few years I've had tripping problems from a
trapped L to E fault in a metal clad light unit, it too 10 years before
this became a problem! Water blowing into an extractor fan, water in an
outside light and the big issue of too many switch mode PSUs in the
house. While some of the genuine faults were a pain and time
consuming to locate the SMPSUs are something I have to live with and
they are taking my overall leakage too near the 30mA limit on the CU.
snip
Apart from the cost, am I crazy?
14 MCBs? Jesus H.



I wanted a high level of discrimination. thats why the outside lights
are on their own RCBO, the outside sockets are on their own RCBO. That
way I don't care if any faults develop outside as it wont affect the
rest of the house.

Similar reasoning for the smoke dets co dets, heat dets and alarm system
being on their own RCBO, that way any faults elsewhere do not then
affect H&S or flatten the standby batteries.

SImilar reasoning for teh boiler being on its own RCBO. it won't get
affected by any faults elsewhere in teh house, and during winter with a
frost protection device, prevent the pipes from freezing and the house
then flooding.

So I ended up with whats called a high integrity CU.