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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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28th Mar 2016, 9:47 pm | #61 | |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
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Re: Beware of fake mains cables.
Quote:
Proper fuses are welded. Look on the website I linked to. BS1363 is very specific. Anyway the point of the pictures was to show the common fakes around not to argue over what is or is not considered a fail. What may have been OK in the 70's IS NOT OK now. A lot of the changes have been due to failures discovered by experience, one of which was loose end caps and crimped wires. The point is, if British standards says it is a fail....then it's a fail. ....if you could find out the supplier/manufacturer!! Sorry you have no idea!
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28th Mar 2016, 10:26 pm | #62 | |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,579
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Re: Beware of fake mains cables.
Quote:
I was speaking to an electrician of many years in the trade and he told me back in 2000 the concern of fake Chinese fuses without a sand filling. When a short occurred in a particular appliance the plugtop fuse blew, literally! The top of the plug was blown off the base by the blast exposing the live contacts. A quite dangerous situation all because the fuse didn't have a sand filling to quench the arc on failure. It must be an absolute nightmare for Trading Standards to keep on top of all these dangerous goods. We hardly had the same kind of problems or worries when we were making our own products. BEAB, ASTA and British Standards have always been good for the industry and are highly respected in my opinion. The audacity of putting the safety approvals on a dangerous fuse is beyond redemption. Regards Symon. |
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28th Mar 2016, 11:10 pm | #63 |
Heptode
Join Date: Jan 2016
Location: Nottinghamshire, UK.
Posts: 676
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Re: Beware of fake mains cables.
The price differences in fuses doesn't help all of which may be perfectly fine and comply with the appropriate BS I suppose the only way to check for piece of mind if worried is to sacrifice one to the hammer to see whats inside?
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29th Mar 2016, 12:09 am | #64 |
Heptode
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
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Re: Beware of fake mains cables.
On some, it suffices to pull the end caps off gently by finger...
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29th Mar 2016, 9:13 am | #65 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
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Re: Beware of fake mains cables.
...and to show some typical examples of fake plugs, connectors and markings please see attached pictures. The plug shows a part-insulated earth pin....not allowed, but that is not the only fault....the pins do not fit a test gauge, being incorrect spacing and also they are too short. They fitted a 13A socket...just but it was a very tight fit. The fake fuse was shown earlier. At the other end of the cable was a standard figure 8 connector...also fake, complete with fake markings. The connecting 'barrels' in these should be 4mm from the end of the plastic, these were just over 1mm. It was also very loose when connected to the appliance (a charger).
Neither the plug, connector or lead had been anywhere near a safety test house before being marketed. Incidentally the mains lead was marked 0.75mm(sq) but when tested was well below the correct cross-sectional area stated.
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29th Mar 2016, 9:24 am | #66 |
Dekatron
Join Date: Apr 2011
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Re: Beware of fake mains cables.
Those figure of eight mains female connectors and others of a similar principle have always made me wonder why they are allowed, consumer safety not of paramount concern?
Lawrence. |
29th Mar 2016, 9:25 am | #67 |
Heptode
Join Date: Jan 2016
Location: Nottinghamshire, UK.
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Re: Beware of fake mains cables.
I will be checking the last ones I bought later Martin!! The plug photos are good examples Sideband.
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29th Mar 2016, 10:02 am | #68 | ||
Rest in Peace
Join Date: Apr 2008
Location: London, UK.
Posts: 2,508
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Re: Beware of fake mains cables.
Quote:
In the UK, because of our unique ring-final system that allows large numbers of appliances to be used on one circuit due to the much greater load diversity, we protect our 13A sockets with 32A breakers and thus the fuse in the plug is an essential component of the system. Quote:
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29th Mar 2016, 10:19 am | #69 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Beware of fake mains cables.
""Quote:
Those figure of eight mains female connectors and others of a similar principle have always made me wonder why they are allowed, consumer safety not of paramount concern? Correctly made, they are safe, effective and economical. These defective types with the contacts incorrectly located in the body can be very nasty, I had one where you could actually touch the contacts with a finger (a real one, not a test finger)."" The point I was trying to make was that as far as I understand it a 13 amp outlet socket is shuttered, plugging one of those leads in is in effect just extending that socket but it's now unshuttered if the female connector is not connected to the device, what's going on... A slight aside...If it were possible I would design the mains outlet sockets so that they could not be switched on unless the plug was fully inserted and that the plug could not be withdrawn unless the socket was switched off. Lawrence. |
29th Mar 2016, 10:57 am | #70 |
Rest in Peace
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Re: Beware of fake mains cables.
The female contacts of normal appliance connectors are significantly smaller than those of normal wall sockets, therefore much less likely to allow accidental contact with a foreign object, again with the proviso that the moulding is correct for the design.
Electrically or mechanically interlocked switched sockets are widely used in industry and mandatory for certain applications. They have been made and used for domestic and commercial applications too. Most used a capture-interlock, where the switch could not be closed without a plug in place and the plug could not be withdrawn with the switch on. MK used it on their proprietary gauge which had a notched earth pin, others used adaptations of standard gauges e.g. Crabtree with a hole through the pin. Wandsworth made a proprietary plug with a slotted earth pin that closed a tumbler switch once the plug was making contact and opened it before contact was broken during withdrawal - there was no user-operated switch and the plug was not captured. BS1363 with sleeved pins and shutters is very effectively immune to accidental contact and is rated to break load, therefore arguably an interlock is redundant. |
29th Mar 2016, 11:00 am | #71 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 3,326
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Re: Beware of fake mains cables.
"The point I was trying to make was that as far as I understand it a 13 amp outlet socket is shuttered, plugging one of those leads in is in effect just extending that socket but it's now unshuttered if the female connector is not connected to the device, what's going on..."
The same applies to all the cables to your hi-Fi, computers, kettles etc that use the 3 pin IEC sockets. |
29th Mar 2016, 11:16 am | #72 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
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Re: Beware of fake mains cables.
Yes, exactly.
Getting back to the fake connector it was mentioned that the metallic part of the socket had to be 4mm in from the face, so that said, imagine a scenario where live chassis equipment was being manufactured, would several live parts visible but recessed 4mm from the user be acceptable? Lawrence. |
29th Mar 2016, 12:26 pm | #73 |
Dekatron
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Location: Leominster, Herefordshire, UK.
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Re: Beware of fake mains cables.
I don't think visibility is the issue here, accessibility is the point. 400KV transmission lines are very visible!
Safety standards require inaccessibility to standard designs of test finger and probes. They don't consider that an "intelligent idiot" poking wires into the end of figure 8 connectors is a risk worth legislating for. No matter how hard you try to make something idiot proof, nature will always evolve a better idiot
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29th Mar 2016, 1:11 pm | #74 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,579
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Re: Beware of fake mains cables.
Talking about accessibility to conductors and fake items aside, has anyone thought of the inherent danger of electric shock from a bayonet or Edison screw bulb holder in say a table lamp if the bulb happened to be missing from the lamp? I always thought that's quite a serious risk and would have thought a shuttered type of holder would have been mandatory.
Symon. |
29th Mar 2016, 1:24 pm | #75 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
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Re: Beware of fake mains cables.
Good point, and getting back to that mains female ended connector, the depth to the contact and the internal diameter of the socket openings reminds me of the control knob/grub screw scenario on live chassis radios, the general consensus of which was to fill the remaining depth of the hole with insulating material as it was considered as a risk not to do so.
Lawrence. |
30th Mar 2016, 3:25 am | #76 |
Hexode
Join Date: May 2015
Location: Northampton, Northants, UK.
Posts: 380
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Re: Beware of fake mains cables.
BC and ES were invented a very long time ago ES should always be connected with the screw collar to neutral. Back in my theatre days, when an artiste requested removal of lamps from dressing room mirror surrounds, we always replaced the lamp with a cork.
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30th Mar 2016, 11:06 am | #77 |
Dekatron
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Location: Heckmondwike, West Yorkshire, UK.
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Re: Beware of fake mains cables.
Yes, nothing fake here, just legacy. There are alternatives nowadays, but the installed base is just too large for now.
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30th Mar 2016, 8:08 pm | #78 |
Dekatron
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Re: Beware of fake mains cables.
Forgot to mention on the post showing the plug, the distance from the live or neutral pin to the outer edge of the plug casing should be minimum 9.5mm. I think this one measured around 8mm so another point to easily check.
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31st Mar 2016, 11:12 am | #79 |
Heptode
Join Date: Jan 2016
Location: Nottinghamshire, UK.
Posts: 676
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Fuse fakes
Following a recent thread about allegedly fake mains leads which leaked over into allegedly fake fuses. As my fuses were inexpensive ones from the internet I was a tad concerned so I broke one open and was very pleased to find all was well this supplier definitely will get a repeat order!
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31st Mar 2016, 11:25 pm | #80 | |
Pentode
Join Date: May 2010
Location: Sandviken, Sweden
Posts: 233
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Re: Beware of fake mains cables.
Quote:
To get back to the original scenario I was given a suitable cable from the electrician where I work. It is mains rated but with three black conductors, primarily meant for machinery, automation and such. He had a whole drum of it. I needed it for a 1920s lamp that I have rewired. Preferably it should be earthed but earthed sockets was not mandatory in Sweden until 1994, so... And the chains would be a problem to earth. Anyway the wiring now is fresh and it hangs out of reach. |
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