Tricky Dicky Posted January 31, 2016 Share Posted January 31, 2016 I agree that the current BS1363 plug as a pretty good design, and as was said by an earlier poster, is probably the safest design in the world, however it does introduce one flaw that was not present in earlier house wiring. The idea of BS546 was that you would run separate supplies which were fused at the fusebox to the maximum current allowed for the type of circuit, so it was only possible to draw 2 amps from a 2amp socket no matter what you did (unless you replaced the circuit fuse, of course). It was far less likely for someone to mess with the fuses in the fusebox though. With BS1363, it's perfectly possible to draw 32 Amps from a ring main socket, which is why individual plug fuses were introduced, not to protect the appliance, but to protect the appliance cable. For example, if you have a table lamp with thin flex, and a BS1363 plug, because the plug cartridge fuses are interchangeable, it is common for these to be replaced with 13 Amp fuses by your average bumbling householder. If you get a short circuit (blown bulb with a short for instance) then the current draw through that thin flex will happily get the flex hot enough to both break down the insulation and cause a fire before the plug fuse blows. With BS546, the table lamp would have had a 2 Amp plug, on a 2 Amp supply, much less chance of a fire. Al Not quite true as most fuses back in the day were wire fuses not cartridges and it was perfectly possible to inappropriately wire a fuse with the wrong fuse wire, and it was often done. Richard Link to post Share on other sites More sharing options...
Junctionmad Posted January 31, 2016 Author Share Posted January 31, 2016 Personally I prefer the Schuko socket. But that's just old contrarian me. The 13A plug is way too massive in my view. But at least we don't have to cut the two pins off leads anymore Dave Link to post Share on other sites More sharing options...
Crosland Posted January 31, 2016 Share Posted January 31, 2016 Well of course if you're as old as me you will remember when houses were wired with different outlets for different applications, and you had different sized plugs and sockets so it was not possible to plug a 15Amp appliance into a 5 Amp supply. Unfortunately though, this eminently sensible idea was done away with. Al Old style 5A round pin plugs/sockets are still perfectly legal and often used for dedicated lighting circuits. My fathers house still had a mix of 15A/13A/5A (and, for good measure, rubber insulation on some circuits) well into the noughties Andrew Link to post Share on other sites More sharing options...
raymw Posted January 31, 2016 Share Posted January 31, 2016 some blueskying, ballpark calculations11W led lamp equiv to 60W filament light output, as it states on the packaging I have before me.Assuming a 3 bed house, maybe 10 lamps on at one time, so 110W required, and filament lighting needs 600W. A common lighting circuit wiring is rated at 6A, so plenty of margin for both.I've not checked, but I assume that mains LED lamps have electronics to reduce the voltage for the LEDs, get to dc, etc. and not just simple current limiting resistors and diodes, but if the lighting circuit wiring was dropped down to 12V dc, then the cost of each lamps electronics could most likely be reduced (may not be passed onto customer, however) (but there would be an initial cost in the line dropping circuit) and there could be possibly small savings in overall power losses through the wiring (low current dc/ low current ac)..Most electronic stuff will be OK on 12V, too. However heaters, kettles, and the like would need pretty thick cables, but TV's laptop computers would most likely be OK on our 240V cable sized ring mains but running at 12V 30A.A few years ago, there was talk of motor vehicle electrics to be at 48V, instead of 12V, but that seems to have all but died out. That was prompted by savings in wiring costs, ease of driving stepper motors, and the like.However, A higher current, but lower voltage can be more dangerous than higher voltage/lower current in many cases, as is dc versus ac.The ring main system saves wire, and fuses at the distribution board, compared to the old star connected 5/15A circuits, particularly with the number of sockets now common. You don't find many mothers plugging the iron into the light socket, these days... So, have half a dozen old car batteries, and run most of your stuff on offpeak elektrickery. (or live in a campervan,,,) Link to post Share on other sites More sharing options...
Crosland Posted January 31, 2016 Share Posted January 31, 2016 11W led lamp equiv to 60W filament light output, as it states on the packaging I have before me. LOL! Don't believe the hype. 4x or 44W would be a fairer comparison. A few years ago, there was talk of motor vehicle electrics to be at 48V, instead of 12V, but that seems to have all but died out. That was prompted by savings in wiring costs, ease of driving stepper motors, and the like. However, A higher current, but lower voltage can be more dangerous than higher voltage/lower current in many cases, as is dc versus ac. There's a lot of equipment designed to supply and use 48V so that would be a good choice to benefit from existing volumes and a good compromise on current and resulting wire gauges. I have had 400V DC up me from a supply capable of 1.6kW Luckily only across the end of a finger but the pain was still intense. Link to post Share on other sites More sharing options...
Junctionmad Posted January 31, 2016 Author Share Posted January 31, 2016 some blueskying, ballpark calculations 11W led lamp equiv to 60W filament light output, as it states on the packaging I have before me. Assuming a 3 bed house, maybe 10 lamps on at one time, so 110W required, and filament lighting needs 600W. A common lighting circuit wiring is rated at 6A, so plenty of margin for both. I've not checked, but I assume that mains LED lamps have electronics to reduce the voltage for the LEDs, get to dc, etc. and not just simple current limiting resistors and diodes, but if the lighting circuit wiring was dropped down to 12V dc, then the cost of each lamps electronics could most likely be reduced (may not be passed onto customer, however) (but there would be an initial cost in the line dropping circuit) and there could be possibly small savings in overall power losses through the wiring (low current dc/ low current ac).. Most electronic stuff will be OK on 12V, too. However heaters, kettles, and the like would need pretty thick cables, but TV's laptop computers would most likely be OK on our 240V cable sized ring mains but running at 12V 30A. A few years ago, there was talk of motor vehicle electrics to be at 48V, instead of 12V, but that seems to have all but died out. That was prompted by savings in wiring costs, ease of driving stepper motors, and the like. However, A higher current, but lower voltage can be more dangerous than higher voltage/lower current in many cases, as is dc versus ac. The ring main system saves wire, and fuses at the distribution board, compared to the old star connected 5/15A circuits, particularly with the number of sockets now common. You don't find many mothers plugging the iron into the light socket, these days... So, have half a dozen old car batteries, and run most of your stuff on offpeak elektrickery. (or live in a campervan,,,) some blueskying, ballpark calculations 11W led lamp equiv to 60W filament light output, as it states on the packaging I have before me. Assuming a 3 bed house, maybe 10 lamps on at one time, so 110W required, and filament lighting needs 600W. A common lighting circuit wiring is rated at 6A, so plenty of margin for both. I've not checked, but I assume that mains LED lamps have electronics to reduce the voltage for the LEDs, get to dc, etc. and not just simple current limiting resistors and diodes, but if the lighting circuit wiring was dropped down to 12V dc, then the cost of each lamps electronics could most likely be reduced (may not be passed onto customer, however) (but there would be an initial cost in the line dropping circuit) and there could be possibly small savings in overall power losses through the wiring (low current dc/ low current ac).. Most electronic stuff will be OK on 12V, too. However heaters, kettles, and the like would need pretty thick cables, but TV's laptop computers would most likely be OK on our 240V cable sized ring mains but running at 12V 30A. A few years ago, there was talk of motor vehicle electrics to be at 48V, instead of 12V, but that seems to have all but died out. That was prompted by savings in wiring costs, ease of driving stepper motors, and the like. However, A higher current, but lower voltage can be more dangerous than higher voltage/lower current in many cases, as is dc versus ac. The ring main system saves wire, and fuses at the distribution board, compared to the old star connected 5/15A circuits, particularly with the number of sockets now common. You don't find many mothers plugging the iron into the light socket, these days... So, have half a dozen old car batteries, and run most of your stuff on offpeak elektrickery. (or live in a campervan,,,) i2R losses make lower voltages a poor choice, in fact if it wasn't for safety , higher AC voltages would make better sense The ring main is a peculiarity to the UK and Ireland. its not really a great solution, and it hasn't been adopted widely elsewhere 48v in cars is very much alive and is being designed into the next version of many hybrids, a search for technical papers will reveal all However, A higher current, but lower voltage can be more dangerous than higher voltage/lower current in many cases, as is dc versus ac. current does the damage, but voltage is needed to breakdown the insulation! , its a ying and yang thing anyway , what were we discussing again Link to post Share on other sites More sharing options...
raymw Posted January 31, 2016 Share Posted January 31, 2016 LOL! Don't believe the hype. 4x or 44W would be a fairer comparison. Bit of a bummer.. Have I got to get out my measuring gear.... what's the lumens of a 60W filament lamp? seems to be about 700lm. The led is supposed to be 806lm, would contravene the trade descriptions act/whatever, if a blatant lie, and it seems bright enough to me. Of course it may be taking 80W to get that, but it is brighter than the previous 60W filament lamp, and also seems brighter than the fluorescent lamps, but many of those were rubbish! Anyway, the point was that I reckoned 10W LED on 12V dc would be quite feasible, with less electronics in the lamp than for 240Vac Link to post Share on other sites More sharing options...
AndyID Posted January 31, 2016 Share Posted January 31, 2016 Bit of a bummer.. Have I got to get out my measuring gear.... what's the lumens of a 60W filament lamp? seems to be about 700lm. The led is supposed to be 806lm, would contravene the trade descriptions act/whatever, if a blatant lie, and it seems bright enough to me. Of course it may be taking 80W to get that, but it is brighter than the previous 60W filament lamp, and also seems brighter than the fluorescent lamps, but many of those were rubbish! Anyway, the point was that I reckoned 10W LED on 12V dc would be quite feasible, with less electronics in the lamp than for 240Vac Hi Ray, I'm not familiar with the innards of LED lamps but suspect it would not reduce the the cost of the electronics. It might even increase slightly. My WAG (wild arm guess) is that they have to use some sort of switched-mode power supply to maintain high efficiency, regardless of the supply voltage. I'm sure someone will straighten me out if I'm wrong Cheers! Andy Link to post Share on other sites More sharing options...
Junctionmad Posted February 1, 2016 Author Share Posted February 1, 2016 Hi Ray, I'm not familiar with the innards of LED lamps but suspect it would not reduce the the cost of the electronics. It might even increase slightly. My WAG (wild arm guess) is that they have to use some sort of switched-mode power supply to maintain high efficiency, regardless of the supply voltage. I'm sure someone will straighten me out if I'm wrong Cheers! Andy actually the circuit in a typical 230 VAC led bulb, the type you see masquerading as a standard replacement bulb, is typically extremely simple, often a rectifier and capacitance based voltage droper in front of it, and then a series of leds in series with the output . No attempt is are to stabilise the voltage http://www.bigclive.com/ledlmp.htm dave Link to post Share on other sites More sharing options...
tender Posted February 1, 2016 Share Posted February 1, 2016 Anyway, the point was that I reckoned 10W LED on 12V dc would be quite feasible, with less electronics in the lamp than for 240Vac But that would draw almost 1 amp, it wouldn't take many of them to exceed the wire rating of the lighting circuit. Link to post Share on other sites More sharing options...
Junctionmad Posted February 1, 2016 Author Share Posted February 1, 2016 reckoned 10W LED on 12V dc would be quite feasible, with less electronics in the lamp than for 240Vac There isn't hardly any difference in components. Maybe a small reduction of one or two. Which would be offset by greater wire diameters and the potential for heating ( i2r) in the feeds. 12v as a domestic supply is just a bad idea. There are numerous issues with high power low voltage supplies. It why industry is typically at 24v , phones are at 50v and PA systems are at 100V Dave Link to post Share on other sites More sharing options...
raymw Posted February 1, 2016 Share Posted February 1, 2016 The capacitor circuit would not work on dc, of course, but maybe on dcc Link to post Share on other sites More sharing options...
DCB Posted February 1, 2016 Share Posted February 1, 2016 Things are getting dangerous, Car Batteries. raymw suggests tongue in cheek using a 12 volt car battery or six. I have spent most of my working life around cars, done a lot of electrical work on them,new looms, spliced a new engine bay loom to an existing loom a few times, made up looms for motorcycles and I've seen the carnage a wrong fuse can cause, or no fuse. Have you ever seen a car battery shorted out? I had a Fiat 127 live lead absolutey glowing yellow and the insulation melting and beginning to burn when a bolt shorted the starter solenoid live to earth. It took around 5 seconds, luckily I managed to cut it with pliers but the battery was ruined. Car batteries boil when shorted, the gas is explosive, the bang is impressive and best of all the gas is acidic so you get acid burns as well. You really do need a decent fuse if you use a car battery, they will cheerfully deliver 50 amps, 150 quite possibly. The best advice re car batteries is car batteries and model railways don't mix. The other advice is any electrical component sold for cars is at least twice the price of the same part for a washing machine or tractor and four time the price from an electrical wholesaler (10X the Ebay price from china allow 30weeks for delivery) Link to post Share on other sites More sharing options...
Junctionmad Posted February 1, 2016 Author Share Posted February 1, 2016 Things are getting dangerous, Car Batteries. raymw suggests tongue in cheek using a 12 volt car battery or six. I have spent most of my working life around cars, done a lot of electrical work on them,new looms, spliced a new engine bay loom to an existing loom a few times, made up looms for motorcycles and I've seen the carnage a wrong fuse can cause, or no fuse. Have you ever seen a car battery shorted out? I had a Fiat 127 live lead absolutey glowing yellow and the insulation melting and beginning to burn when a bolt shorted the starter solenoid live to earth. It took around 5 seconds, luckily I managed to cut it with pliers but the battery was ruined. Car batteries boil when shorted, the gas is explosive, the bang is impressive and best of all the gas is acidic so you get acid burns as well. You really do need a decent fuse if you use a car battery, they will cheerfully deliver 50 amps, 150 quite possibly. The best advice re car batteries is car batteries and model railways don't mix. The other advice is any electrical component sold for cars is at least twice the price of the same part for a washing machine or tractor and four time the price from an electrical wholesaler (10X the Ebay price from china allow 30weeks for delivery) hah, try working with Large format Lithium Ferrous Batteries , the short circuit current is truly " epic ", dave Link to post Share on other sites More sharing options...
PatB Posted February 1, 2016 Share Posted February 1, 2016 Given that, I suspect, heat related electrical accidents (ie fires) are far more common than electric shocks, I suspect that dropping the domestic voltage, and hence increasing the currents drawn and consequent heat management problems, would not have a net safety benefit. Link to post Share on other sites More sharing options...
RMweb Gold martin_wynne Posted February 1, 2016 RMweb Gold Share Posted February 1, 2016 Wooden boxes? linked from: http://www.radioparadise.com Martin. Link to post Share on other sites More sharing options...
RMweb Premium dhjgreen Posted February 1, 2016 RMweb Premium Share Posted February 1, 2016 Wooden boxes? linked from: http://www.radioparadise.com Martin. Martin,Glass/ceramic insulators though Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted February 1, 2016 RMweb Premium Share Posted February 1, 2016 Wooden boxes? linked from: http://www.radioparadise.com Martin. How tall (high) is it? Link to post Share on other sites More sharing options...
raymw Posted February 1, 2016 Share Posted February 1, 2016 Interesting, probably a pre-nationalised pole, but with a preform on the stay wire, probably about 2kV. Not current standard UK, maybe private or foreign. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted February 1, 2016 RMweb Premium Share Posted February 1, 2016 You don't find many mothers plugging the iron into the light socket, these days... Not sure anyone uses irons in the way they used to. Link to post Share on other sites More sharing options...
Glorious NSE Posted February 1, 2016 Share Posted February 1, 2016 Kevin, according to the signage only the left side is High, the right side contains all the voltage. Safety first! Ref Paul's comment about nuclear layouts - many years ago I had a lady with two small kids ask me at an exhibition what that cute little freight train was for, when I told her it transported nuclear waste she told me that was disgusting, shot me a dirty look and dragged the kids off without another word...20 odd years later I still don't know whether she thought we'd used real nuclear waste or what... Link to post Share on other sites More sharing options...
RMweb Premium Reorte Posted February 1, 2016 RMweb Premium Share Posted February 1, 2016 Pity about the LEDs, I was under the now mistaken-sounding impression that most of their remaining ineffeciency, and where they produce heat, was in the gubbins to step the voltage down so a dedicated circuit just for them could eliminate that. Doesn't sound practical now, dratted physics. Link to post Share on other sites More sharing options...
Junctionmad Posted February 1, 2016 Author Share Posted February 1, 2016 I like the pole picture martin , The position of the warning signs is most interesting, rather like a sign immediately over a hole in the ground a sort of " mind the drooooooooooop" . or perhaps the birds can read in that locale Link to post Share on other sites More sharing options...
RMweb Premium Reorte Posted February 1, 2016 RMweb Premium Share Posted February 1, 2016 I like the pole picture martin , The position of the warning signs is most interesting, rather like a sign immediately over a hole in the ground a sort of " mind the drooooooooooop" . or perhaps the birds can read in that locale "Mind the drooooooooooop" reminds me of finding "Danger - deep excavations" by a mine shaft once - a long way into an old mine, in a location that needed squeezing through partial collapses and clambering up and down a couple of (small) shafts to reach, i.e. somewhere no-one is likely to see unless they've got a reasonable idea of what they're doing. I assume someone put it there as a joke. Link to post Share on other sites More sharing options...
RMweb Gold martin_wynne Posted February 1, 2016 RMweb Gold Share Posted February 1, 2016 My favourite sign is this one: Martin. Link to post Share on other sites More sharing options...
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