Date: Wed, 23 Jan 2013 01:12:58 +0100 From: "Julian H. Stacey" <jhs@berklix.com> To: Steven Chamberlain <steven@pyro.eu.org> Cc: "freebsd-fs@freebsd.org" <freebsd-fs@freebsd.org> Subject: Re: ZFS regimen: scrub, scrub, scrub and scrub again. Message-ID: <201301230013.r0N0CwUH054867@fire.js.berklix.net> In-Reply-To: Your message "Tue, 22 Jan 2013 21:56:53 GMT." <50FF0B25.3050009@pyro.eu.org>
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Steven Chamberlain wrote: > On 22/01/13 19:28, Chris Rees wrote: > > On 22 January 2013 19:01, Zaphod Beeblebrox <zbeeble@gmail.com> wrote: > >> On Tue, Jan 22, 2013 at 4:11 AM, Adam Nowacki <nowakpl@platinum.linux.pl>wrote: > >>> This is what was in my wall: http://tepeserwery.pl/DSC_0178.JPG > >>> > >> Damn, son. That socket is obviously not rated for whatever you used it > >> for. > > > > That is a standard European socket, which are normally rated at 13A. Re. Eurpean sockets: I doubt 13 Amps (though I don't know Polish system, possible I suppose) British square pin are 13 Amp. German continetal etc are not. This (Polish?) socket looks similar to French French are (marginaly better than German & Austrian & North Italian/South Tyrol) Continetal wiring standards I've seen are shamefuly dangerous comparedto British (which are to better standard, cost more per equipment & more work to install) In a German rental flat here, one of several hundred in a big, not cheap complex built in Munich in 1985, there are just 16 A & 10 A trip fuses. I suspect a lot is spur wired, not ring main. Certainly it's combined lighting & floor power on 1 fuse per several rooms. No Earth trip, though I'm told it should have one (but I wont commit myself if it Should by law, as I've not myself researched German law/ standards on that) Naked socket with unscreened holes & no switch, between the 2 hand basins in the bathroom, inches apart from the basins. a 2nd socket for clothes washing machine in bathroom. a light switch switch, not ceiling pull cord in the wall. All quite normal by German & continental standards, all appalling to a British electrician. What is shown in http://tepeserwery.pl/DSC_0178.JPG I suppose is Polish, never been there, but looks just like a French style socklet (same material used as German & Austrian & very North Italian (=Sued Tyrol), But the French (& I see Poles) at least achieve the possibility of differentiating neutral from live, by virtue of the offset earth pin. These (type of) sockets are rubbish compared with British 13A sockets. Reasons: No chance of a switch (cheap British one dont, decent ones do). Big reason: see the tiny claws (more visible on left) ? Leftmost screw pushes tthem sideways into the wall. That's all that holds socket in wall, 2 claws; after a while they work loose. If you've got a vacuum cleaner or kettle plugged in (that needs firm contact for all the current, to avoid getting hot), there's a heavy outward force out of wall when unplugging. (I always use one hand on plastic to help it Stay in wall, whith other hand on plug to pull out. Another reason: all that naked metal when the cover is off (a British socket is a lot more covered, much lower chance of electrocution at 230V in Europe) Another reason: UK plugs also have variable 2/3/5/13 amp fuses in plugs. Continetal sockets supply up to room circuit fuse rating, a lot more than many appliance cables can take. Another reason: Polarised Live & Neutral (well at least French & Poles achieve that, Germans Austrians & North Tyrol fail. They like crap sockets on the continent, as seen in picture 'cos you just a use combi circular saw with drill in the widdle, to quickly pilot a hole, then sink bigger circular hole in wall. & then bung in a cheap circular plastic cylinder (that the metal claws eat into & scratch out of over the years) In Britain, you have to hack out a square hole (a lot more work, then put in a more expensive galvanised steel square cavity box, then bang in several masonry nails sideways to hold the steel box inplace, then screw in the more expensive better socket, with proper metal thread screws into screwed holes that make a good grip. The plastic cover on British sockets is much thicker & stronger In Munich, Schiller Str (main computer/ PC street) sold British polarised square plugs & sockets as high quality luxury equipment at several times UK prices. Much continental wiring is Sub Standard & would be condemned under British (ex IEE as was) wiring regs. British plugs are admittedly an absolute swine if you walk on them accidentally bare foot, & clunkier in a laptop case, but the plugs & sockets are _Much_ better, What cost a life or a burnt building. ? > Maybe they don't work very well with paint splattered inside them. > > My guess is the paint was slightly metallic or conductive, so a current > was flowing between one of the screw terminals on the right, and the > bolt in the mounting bracket (which is probably earthed). > > The socket may have been supplying a lower voltage as a result, The voltage would only drop sufficient to count as brown out if there was horrendous heat evolved inside plug / socket combo. These crappy continetal plastic covers suffer from heat easily, but you'd need very little voltage drop to cause the browning seen. > hence > the equipment suffering brownouts. (But it seems the UPS wasn't > sensitive enough to this?) > > Ideally a circuit breaker would have tripped before anything got hot > enough to melt, but in this case the heat in the right-hand-side rail > (in a wall, with no air circulation) became enough to discolour the > plastic. I think it's lucky it didn't cause a fire. > > In the UK most house/office socket circuits are supposed to be protected > by an RCD, which are extremely sensitive to fault currents like this > flowing to earth. Probably just an HR high resistance bad contact causing heat, I've seen so many loose continetal sockets, relatively few UK 13A ones by contrast. When mean or shops closed, I remove socket & file the holes (after fuse off :-) Fine emery (black sand) paper is good to ploish plug contacts. Ive know many public in Britain & Germany use plugs for many decades, till pins are really dirty, & they never think to polish plus pins. So easy to do, even if it takes an electrician to remove & replace or clean (or tighten springs in) a socket. PS 2 pin multi way continental adapters are also crap: Insert 2 pin plug fully in an adapter, & you can feel the metal contact is sometimes off, or often almost off, ready to be high resistance or fail 'cos its gone too deep, 'cos too much of the shaft is plastic, & not enough metal along the tip. Can occasionaly be cause of eg laptops & electric toothbrushes, & razors not charging. > If there are any more sockets in that room/building I would definitely > check all of them! (Carefully, with the supply disconnected, of > course). Or an insulation/leakage test of the circuit by an electrician > would have detected this. > > > checksum errors on multiple > > disks, all fixed thanks to raidz2. > > Well, that's some relief :) > > Regards, > -- > Steven Chamberlain > steven@pyro.eu.org Cheers, Julian -- Julian Stacey, BSD Unix Linux C Sys Eng Consultant, Munich http://berklix.com Reply below not above, like a play script. Indent old text with "> ". Send plain text. Not: HTML, multipart/alternative, base64, quoted-printable.
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