Thread: RCDs in series
View Single Post
  #44   Report Post  
Posted to uk.d-i-y
Andrew Gabriel Andrew Gabriel is offline
external usenet poster
 
Posts: 11,175
Default RCDs in series

I must be bored, as I find myself replying to a Drivel posting...

In article ews.net,
"Doctor Drivel" writes:

High trip current? 16A MCBs or RCBOs on 8 sockets is not high. If a simple
fuse fails in a plug the protection is a 32A MCB (or fuse)


The beauty of a simple fuse is that it doesn't fail.
If it blows, you know exactly which appliance caused it to do so, as
it's tied to the appliance. When a continental circuit blows, you have
no idea which appliance did it (unless one of them is also emitting
smoke), nor if it's a faulty appliance or if you just overloaded the
circuit (which is also all too easy to do) or if it's a faulty circuit.
UK system handles that much better, which is not surprising as it's a
newer design which was intended to avoid that problem.

There are unprotected openings now in some sockets I have seen.


No there aren't.

There is a standard to where live should be connected, but most don't stick
to it.


Considering the two most common continental sockets, the Shucko
has a completely reversible plug, so wiring up the socket in any
particular way would be pointless. The French/Belgium plug isn't
reversible in the same way, but you'll find each socket on a double
socket or 2-way adaptor is hard-wired the opposite way around, so
there's no standard there either. Furthermore, some areas which
use these connectors don't have a live and neutral, as neither
conductor is guaranteed to be near earth potential, which again
makes any differentiation of which pole is live completely
meaningless. So your statement is completely wrong.

"improved safety of the ring" Where? A radial circuit with RCBOs, tripping
on neutral and live, on each circuit is much safer. The UK ring system


You have to switch both poles when you don't have a live and neutral.

trips on 32A and only the live. Most new Continental systems have RCBOs.


No they don't.

Fires in the UK are caused by the same problem. Most homes I see have
trailing extension leads, especially around computers, TVs, etc. Most homes
need banks of 6 wall of sockets Do you see them?


Many of the radial schemes limit the number of sockets you are
permitted on one circuit. This makes it much more complicated to
add extra sockets, as you'll usually find you need a new circuit,
and often a new CU. Hence the very widespread use of trailing
socket blocks and multi-way adaptors on the continent.

There would be. A 16A RCBO at the CU, rather than a 32A RCBO. 1363 relies
on old hat fuses in plug tops.


BS1363 limits the effects of a fault to the faulty appliance.

If I did a re-wire, it would have radials and RCBOs. RCBOs are cheap in the
likes of France and buying a CU complete with them (Legrand for e.g.), they
are "much" cheaper than the UK, where RCBOs are extortionate.


I've never once seen an RCBO in France, and Legrand don't even
appear to sell them in France (although they do in the UK).
The french do have whole-house RCD's though, and as they are part
of the suppliers works, you can't remove them. Although they are
rated 500mA, an earth fault whilst you are on holiday will result
in thawed freezer and dead tropical fish, etc.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]