On Sunday, October 09, 2011 10:07:26 PM andy pugh did opine: > On 10 October 2011 01:46, Steve Blackmore <[email protected]> wrote: > > Fused plugs are a really good idea, and essential with the way we wire > > using ring mains :) > > I think that is two correct but unconnected statements. > > The plug fuse is intended to protect the appliance flex (the device > should be internally fused, if it matters). The idea is that a short > in the appliance can't burn out the flex between the plug and > appliance. > The main circuit is protected in the same way by the main breaker, and > the incomer is protected by the 100A fuse in the box we can't touch > > :-) > > The thing is, that the main breaker for the circuit is sized for the > ring main capacity, and ring mains are bad. (oddly, this was one of > the long running arguments with my ex. She seemed to think because she > used to work for MK that her opinions were of more value than mine.) > The problem is that whilst they can give you twice the capacity for > the same wire size, there is no way to detect a wire break which > halves that capacity.
And IIRC, our NEC prohibits that, for exactly that reason on my side of the pond. > I do follow my dad's protocol of not actually breaking the wire at the > sockets (he strips the wire in the middle, leaving an unbroken > conductor) > > So, I agree that the plug fuse can protect a dodgy ring main, but it > is in the wrong place to do that by design. > > If I wire a house I would wire a ring using spur-rated wire CSA, I > think. Just in case. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) It doesn't matter whether you win or lose -- until you lose. ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
