Heigh-ho. Anyone else know?
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11 years ago
Are 3A plug fuses really necessary? Why not always 13A?
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11 years ago
handheld transceiver from China recently.
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strange thing was that the charger supplied had a Euro plug, so didn't fit this adapter anyway.
The black sleeving on the pins appears to be thin heatshrink that I could easily pick odd with a fingernail.
I wonder what internal protection a wall-wart with a Euro or Stucco pins has to have compared to one with our 13A pins? Without an x-ray machine, you've only got their word that they are safe, and they are not only at the mercy of a 32A MCB.
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11 years ago
If I just reach in this drawer...
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11 years ago
It was around the time the voltages were harmonised at 230V, flexes were marked and CE marking came in.
1995?- Vote on answer
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11 years ago
Lol, which to be fair I had completely forgotten about until your comment prompted me to search for it (well it was 18 months ago!)
Still nice to know that even of my memory is going I am still consistent (or predictable!)
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11 years ago
clock plugs use a smaller fuse. They are 19mm long as opposed to 1" for BS1362.
CPC stock 1A,2A,3A,5A,7A,10A & 13A in BS1362 size
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11 years ago
That's about the size of it.
Years ago a "Euro-plug" was designed. It had no fuse and was a throwback to the fifteen amp plugs we had nicely got rid of. I think it was sixteen amp. Fortunately it was abandoned. MK actually started making them.
I think the 13a plug is the only one in the world with a fuse. There was another where the fuse was a screw-in pin on the plug. Haven't seen one for years.
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11 years ago
Exactly. Like in the house I was working at this week. the best earth fault loop reading I could get on the 30A fused socket outlets was 5.6 ohms.The worst, 9ohms. At the 'best' socket, with 5.6 ohms, at the measured voltage of 247V, it would be passing 44 amps, which just wouldnt break the fusebox fuse.
At the worst socket, it would be passing 27 Amps, which may break a 13A fuse, but I doubt it would do it in 0.4 of a second, more like a second, which is enough to kill. A 3A fuse would break it immediately (well, ok, in less than half a second). The fuse in the fusebox will be happlily buzzing away, passing the current for half an hour before it broke. The figures were likely to be worse in the evening, as other people came home, and the voltage may drop a little, allowing more current through.
Ok, thats an extreme example, but a true one, so the final fuse rating can have safety implications, hence best to put the lowest rating possible in.
Alan.
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11 years ago
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=A0 =A0 =A0 =A0|
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D/
Not all faults are dead shorts. Transformer overheat/burnout for example. Not all equipment has internal fuses.
3Kw/13a of sustained energy in an electronic device/small electric motor could start a nice little fire.- Vote on answer
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11 years ago
There was indeed. One was physically smaller than the plug fuse. You found them in mains electric clock connectors. Of course, you never see mains clocks any more except as radios. There have been all sorts of odd sizes over the years.
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11 years ago
I remember those thin leads. My '60s soldering iron had a lead about half the diameter of (today's!) CAT5 patch cables. My assumption up until now has been that globalisation has resulted in all leads being designed for the unfused plugs used in most of the world outside the UK.
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11 years ago
Optional mains plug fuses were in use a century ago in the UK, but they were open wire links in plugs that were often wooden. They were banned in 1913 as a fire risk.
NT
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11 years ago
do you mean the CEEform plug? MK Commando, etc. Very much in use.
some of our old 5A round pin plugs had fuses. Perhasp they still do in India.
those were made by D&S.
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11 years ago
For the purposes of this discussion they are (its in the definition of "fault current")
Transformers are unlikely to be able to present any sustained load above their design maximum for long - the wire size on their primary winding will typically be *significantly* thinner than that of the supply flex.
If it needs overload protection then it is required to have its own protection. Remember in most markets, protection via a plug fuse is not an option.
Which would be an overload and not a fault. If there is a plausible overload scenario, then the device in question must include its own protection.
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11 years ago
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=A0 =A0 =A0 =A0 =A0|
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D/
Is it Panto time yet? Oh yes they are.
And all short circuits are faults.
Anything else is an overload.
MBQ
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11 years ago
1,2,3,5,7,10 and 13A fuses are all still available. I remember seeing 1A fuses in clock plugs - though some clock plugs used fuses with a different mechanical size just to be awkward...
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11 years ago
On 08/11/12 10:49, Man at B&Q wrote: all short circuits are faults.
What a peculiar version of the english language you speak...
Lets say we have an SMPS, and due to a fault in the main 400V reservoir on the mains side, it starts leaking several amps ...
You are saying that's not a fault?
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11 years ago
Welcome to the strange world of Aurthur Brown. The wiring regs use 'fault c= urrent' to specifically mean a dead short, but obviously in the real world = appliance faults occur that produce current (fault current by definition) t= hat covers the full range from a smallish increase than only overheats a mo= tor to a dead short. Introducing a narrow perspective definition that appli= es specifically to wiring and using it outside of where it makes good sense= is not productive, and insisting it must mean that elsewhere is illogical.= In the world of electronics (which many appliances are) fault current does= not usually mean a dead short across the mains.
In practice not all has, particularly old appliances
Old UK appliances were typically designed for only the UK market
But in practice a fair few don't. There are still significant numbers of ol= d electrical goods in use spanning the range from pre-95 to 1920s. And not = all new goods meet the standards legally required of them.
NT
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11 years ago
Well, it is faulty, but in the jargon, that is not a fault current.
MBQ
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11 years ago
That seems OK as few computers would exceed 1kw=20 but if that lead was used as a kettle lead.....
No idea perhaps they had a lot of 10Amp fuses spare I have, I think they ar= e black, 13Amp brown and 3A red.=20
In the days ofm teh first laser printers they took quite a heaft startup cu= rrent, in fact you shouldn;t put laswer printers on sureg protection blaock= s either. Not sur eif it's still true as I can't believe the modern USB las= erpriners would need a high startup cutrrent.... =20
I broguht about 100 "Y" leads that have two IEC sockets on the end and the= y have 13amp fuses. There's a health and safety notice that says were not a= llowed to use them as you can't connect two pieces of equipment to one plug= .
=20