Lately I've noticed much of the Chinese computer stuff has a 13 amp fuse when it should have a 3 amp. Not everything does but I am finding this increasingly common. The latest example is a generic laptop charger, maximum current draw is 2 amps, it was fitted with a 13 amp fuse.
One of my own external hard drive cables set on fire lately, I managed to cut the power before it was a major problem, the wires in the 240v power cable were so thin it was thinner than speaker cable, what was worse is that the fuse in the plug was a 13 amp.
I am now finding I am buying thicker 13 amp cables and fitting a 3 amp fuse to them as I can no longer trust the importers to ensure the cable meets UK specifications.
I just don't understand why the market is flooding with potentially dangerous products and it is the big suppliers supplying them.
On the plus side I bought an IDE to USB bridge today complete with its own transformer, the power cable was nice and thick and it also had the correct 3 amp fuse in it. The transformer also had lots of different standards on it unlike many which simply comply (apparently) to CE and not the German and American safety standards.
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The fundamental purpose of the fuse in the plug is to prevent the supply lead from bursting into flames, rather than protect the appliance itself; which should have its own internal protection. So, sometimes it is OK to have a 13A fuse on a 2A appliance, if the supply lead is rated for 13A or so continuous.
OTOH if the supply lead is indeed really thin then it shouldn't have a 13A fuse in the plug and wants reporting to trading standards.
CE is the only approval required within the EEA*, it superseded any UK or German requirements. I'd expect most products these days to be 'global' though and include the main US requirements ( FCC and UL)
* EU plus some others
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I had one transformer which didn't even meet CE standard.
I will try and take a picture of the cable, it is so thin the coper was thinner than bell wire, but the insulation was a bit thicker. Still it over heated, shorted and caused a nice popping sound.
It is that incident that has now got me checking for fuses etc.
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>> I had one transformer which didn't even meet CE standard.
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Loads of non CE stuff on eBay, even new stuff from UK sellers, and with the price of copper going up & up the situation is likely to get worse.
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Loads of CE marked stuff that aint. There is a lot of counterfeit marked cable out there.
Still as I told you rats, if its good enough to power a transformer, bell cable is good enough for speaker cable!
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The cable burst into flames, so it was not good enough to power a transformer. And yes I am aware of the fake cables and fake CE markings, how can I tell without opening up the transformers and measuring tge resistance of cables though?
I Am also worried about but I am not sure if trading standards will be bothered unless I can show the problem is on a massive scale.
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You wont tell how much current a cable will carry by measuring resistance. You can get a rough idea by measuring voltage drop along the length at high load, but on the whole you can "measure" the cable at home.
They even wrap a thin amount of copper round plastic or cotton core to make the cable conductors look thicker.
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Why is this allowed to happen though? I wonder how common these types of shorts and fires are due to too thin illegal cable? I mean I imagine 90% of the time when a cable catches fire the user notices before it causes any real damage.
I can avoid the PC power supply issue by being careful which brand I choose, but on transformers which come with other electrical items they seem to be too many cheap fakes.
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I took my old laptop PC to be repaired (power supply connection had become loose) they wouldn't give me the el-cheapo e-bay sourced power supply back as it had failed electrical testing. Makes you wonder how many houses burn down because of this shoddy crap.
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Rats, hope none of your client's houses ever burn down due to fault wiring on accessories you have fitted!
Seriously, worth making sure your public liability or whatever it is covers it!
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I do not do any wiring, if I replace any power cables it is only the kettle type ones, and I fit them with lower rating fuses where required.
I certainly not not modify anything in that sense of the word.
A thicker cable will cause less resistance at a given ampage hence won't heat up as much and hopefully avoid any fires.
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That is great they did that, too many computer shops just sell any old crap. I use cheap stuff on my bench but I will never sell it to customers. The problem is even well known brand stuff often dosn't meat the specs I would like.
I recently bought a generic laptop charger made with the Trust brand on it, it was CE marked but that was about it, it did have the correct fuse etc but I could not tell which manufacturer made it. I like to be able to trace them to the source but I suppose even that can be faked.
You can't make a good cheap transformer and I personally want all this cheap Chinese stuff banned unless they can proof it is made properly.
I've been looking into offering PAT testing but not sure if its worth it. I would need expensive test equipment too, I do have a near £200 UNT-T Oscilloscope which is very handy for measuring how stable the output voltage is, but is no use for PAT testing. The courses and equipment would probably be too much.
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Then of course as DD pointed out in a previous thread there's the 'China export' logo designed to fool punters:-
www.cemarking.net/chinese-export/
www.webcitation.org/5rHyRoXb2
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Not a computer issue, but re quality/Trading Standards! Kettle (3kW?) went bang: smoke and flames from base. Maker uninterested, so I got in touch with Consumer Direct who were also in couldn't be bothered mode. They denied I could contact a real live TS officer direct. I had dealings in the past I knew they still had a presence in Preston. Even though I didn't expect feed-back personally I wanted TS to have the info as the event could have been more serious if I hadn't been in the right place. At least TS made a semblance of interest: they would pass on the details to the team dealing with the maker/importer. Much effort, probably little effect. Consumer protection on downhill slope?
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As a qualified PAT tester, checking the fuse rating is one of the first things I do.
More recently appliance manufacturers have standardised on two plug fuse ratings, 3A & 13A and adopted appropriate flex sizes.
www.pat-testing.info/plug.htm
However, I'm still old school when it comes to fuse ratings. I divide the wattage of the appliance by the voltage and then with the answer I get fit the nearest rated fuse.
If you follow the suggested guidelines, then for example if something draws 4 amps, you are supposed to fit a 13 amp fuse. No way would I do that. I would fit a 5 amp fuse, or if there is a chance of a surge when the appliance is first switched on, then I would fit a 10 amp.
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It is a shame 10 amps are hard to find, I found one in a printer power cable once and it was the first I knew that they existed.
Most computer equipment draws less than 3 amps, so a 3 amp should normally be fitted. I find the products that do have a 3 amp fuse usually have a sticker on it saying that.
Another illegal China imports is plugs which have no fuses, they have the BS1363 pin layout but the plug is smaller and there is no fuse. Not seen one myself but I know others have come across them.
One manufacturer of Chinese imports I do like is Sunny, they always seem quite heavy and according to the stickers they meet many many standards. FSP is another supplier of high quality transformers.
I think most house hold goods are generally ok and seem to be made to a higher standards, for some reason it is computer equipment which often leaves a lot to be desired.
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>>However, I'm still old school when it comes to fuse ratings.
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Me too I have 1, 2, 3, 5, 7, 10 or 13amp fuses in stock.
I have come across a correctly rated fuse that was not tight in its MK plug.
In the circumstance an old fashioned cube shaped adapter saved the day. The plug was charred as was the adapter so much so that the skirting board to which the 13 amp socket was attached was also starting to char.
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>> As a qualified PAT tester, checking the fuse rating is one of the first things I do.
Kept that quiet didn't you? I'd say Pat can sometimes have quite a short fuse but most of the time she's a honey....
:-)
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I nearly caught you Humph, before you went to bed too:)
Pat
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That, Humph, was very funny - now go and buy that Fiat - you know it makes sense !
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>> I just don't understand why the market is being flooded with potentially
>> dangerous products, and it is the big suppliers supplying them
>> >> I had one transformer which didn't even meet CE standard.
>> >>
>> Loads of non CE stuff on eBay, even new stuff from UK sellers, and with
>> the price of copper going up & up the situation is likely to get worse.
Sounds like the basis of a good Daily Mail scare story there, anyone want to send them a link to this thread? They'll spin it into "All new appliance cables WILL catch fire" in no time...
Last edited by: Dave_TDCi on Sat 18 Jun 11 at 00:57
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I went to a house fire caused by a secondhand telly bursting into flames overnight while on standby.
It was interesting to see the aftermath as the firemen were still damping down.
Black soot everywhere and the smell was on my clothes for days, even though I didn't touch anything.
The fire had been out for a while by the time I got there, but a charred windowsill popped back into flame as I looked at it.
"That's why we hang around for so long," said the fire chief.
In any job, there's no substitute for experience.
Last edited by: Iffy on Sat 18 Jun 11 at 09:14
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The fire had been out for a while by the time I got there, but a charred windowsill popped back into flame as I looked at it.
Wasn't there a similar scene in The Omen ?
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...Wasn't there a similar scene in The Omen ?...
Might have been.
It was a strange thing to see, and had an element of unknown forces about it.
I think most of us would have regarded the fire as extinguished and would have been happy to turn our backs.
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My fire went out years ago !
Anyway, what are you all fussing about ? A 6mm bolt cut to size fit in a plug nicely !
Only joking.....honest !
Ted
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...A 6mm bolt cut to size fit in a plug nicely !...
And you don't need loads of fuses if you have a paper clip or some tinfoil to hand.
Last edited by: Iffy on Sat 18 Jun 11 at 17:19
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Although never a smoker, I used to scavenge fag paper when I saw it in the old days, indispensable for unexpected electrical emergencies on a bike (but being Japanese it never happened !) - I suppose fag packets don't have that feature any more.
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Always check the fuse when you buy electrical item - spamcan61
