It seems that a suspect batch of counterfeit plugs has entered the UK market. Many of us will have been stung online before with counterfeit goods, either from internet auction sites or other outlets but it’s not the branding that is in question with these items – it seems they have been molded as BS1363 (the British Standard for a normal 3-pin plug) but don’t meet the requirements. If you have recently had your items PAT tested then you should be fine – an experienced PAT tester would pick up the problem at the visual inspection stage, failing that the lead and plug would fail the earth bond test. It is easy to spot when you’ve seen one – the earth pin (the longer pin at the top of the plug) is half insulated (see image below).
To meet the British Standard, this can be fully plastic for Class 2, non-earthed appliances – you may have mobile phone chargers and other low-voltage power supply units like this – but for all other appliances it should be solid brass with no insulation. The live and neutral pins are supposed to be insulated, this is to protect the fingers as the plug is removed – the pins will be disconnected from the mains (connection is made at the back of the wall socket) before the user can touch any metal part. However the earth pin connects at the front of the socket. This is so that when the appliance is being plugged in, it is earthed safely before the live and neutral pins are connected and current begins passing through the item. It remains safely earthed until after the live and neutral pins are disconnected when unplugging the item. If the above lead was to be plugged into a wall socket, the metal earth connectors inside the socket would be touching the plastic insulation, not making an earth connection as required.
Why is this important?
In the event of a problem with the appliance, such as a connection between a live wire and a metal part of the appliance, the earth pin is designed to make sure the current flows safely to ground, and that the user isn’t at risk of getting an electric shock. The insulation on the earth pin will break this ‘safety circuit’ and the metal parts of the appliance will potentially be carrying a live electric current.
What should I do about it?
The easiest thing to do is get staff to double-check all your equipment. A quick visual inspection will find the problem. In the event you find any items with semi-insulated earth pins, remove them from service immediately. If you know where that particular lead has been purchased from, contact the retailer for a full refund. Trading Standards should also be made aware if you think the retailer/manufacturer is knowingly selling these counterfeit items. IEC (kettle leads) cables that supply power to many appliances, such as PCs, monitors and printers are the most common kind found. Do not attempt to repair with a replacement plug as other sub-standard materials may have been used in the production of these items.