More fake mains plugs

I was recently handed a USB docking station that was sourced via Amazon UK – the USB dock’s a popular gadget that enables SATA hard disks to be read (or written to) using a USB port and it also reads memory cards.

Two fake UK mains plugs made in China (click to see)Problem is, the unbranded mains power supply included with it has a UK power cord that’s counterfeit and potentially extremely dangerous.

For starters, the UK plug (photo, left) is falsely labelled ‘BS1363/A’ but it’s anything but legally compliant. The giveaway is the earth (ground) pin, which is part-insulated or sleeved the same way the live and neutral pins are. However earth pins must either be solid metal or solid plastic (only for double insulated equipment that needs no earth).  Metal ground pins must not be sleeved.

By design, the earth pin is longer and connects first, so that the equipment is immediately ‘earthed’ the moment the plug is inserted before the mains supply is applied. However a sleeved earth pin might not connect to earth properly, if at all.

The BSI kitemark symbol on the plug is a poor imitation and the 13A fuse inside is also fake: the end caps simply pull off and it isn’t sand-filled to suppress a melting fusewire, so the plug could therefore explode and blow the plug out of the socket [updated link]. Lastly, the lead’s mains colour codes are incorrect (blue, pink and green) and the weak insulation is so bad that I can strip it off between fingernails without trying.  We cannot know what the "copper" strands are actually made of but I doubt that it's copper.

An authentic Uk 13A mains plug - note the solid earth pin (click to see)Take a look at www.bs1363.org.uk for more details of counterfeit Chinese mains plugs and links to videos.  Six years after this kind of thing was highlighted to Amazon, fake electrical goods are still being sold into the UK.

 ... and more counterfeit cables in the lab

On another occasion I tussled with an unbranded Chinese-made power supply. Its UK mains plug is illegal in every respect and it’s the most dangerous mains connector I have ever seen (photo, right). It is way too small (so a live plug can be grasped all round), it's unfused (so may cause a fire) and it has a sleeved earth pin again.

It’s marked as ‘10A 250V~’ but the mains cores are the wrong colours (blue, pink and green again) and the insulation is so thin that it can be scraped off with a fingernail. If it were kinked, trapped or twisted in use, I have no doubt the insulation would easily break down and cause a fire.

I counted 20 “copper” strands in the fake wire. Using a digital micrometer, a strand measured 0.05mm diameter so its radius is 0.025mm, and so the cross-sectional area of each strand is (A=pi.r²)  0.002mm².  The total CSA of each mains core was just 0.039mm².

By comparison, the lightest-duty connecting wire sold by Maplin is 10/0.1mm (i.e.  10 strands, each 0.1mm diameter or 0.00785mm² in area). Therefore 10 strands of this authentic cable yields a total CSA of 0.0785mm². It’s rated at 0.5 Amps.

At best, the Chinese counterfeit mains cable has half the CSA of the light-duty Maplin cable, so let’s be generous and rate it at 0.25 amps. At 240V a.c. that’s good for a 60W light bulb at most.  It is highly likely the cable is not pure copper anyway, but a cheap alloy of maybe steel or aluminium which reduces its capacity far more. Tests have shown how fake cables fail earth continuity tests, so these fakes are a fire hazard and they risk causing an electric shock.

If you see any such fake cables, cut off the plug and destroy the lot immediately. I wrote about counterfeit mains cables entering the UK from China here.  It describes how UK retailer Wilko had to remove counterfeit Chinese-made mains cable from its shelves.