HomeCounterfeit 13 A Plugs
In previous articles we’ve looked at counterfeit plug fuses, substandard chargers and unsafe adaptors sold online. Unfortunately, counterfeit rewirable 13A (BS 1363) plugs are also being sold. The plugs in this article were purchased from a UK-based eBay seller. For more real examples found during inspection and PAT testing, see our hub page on counterfeit electrical equipment.
On initial inspection, the two plugs we purchased appeared to be fairly standard rewirable 13 A plugs. The wiring cards and retaining screws were supplied in a separate plastic bag.
The first indication that these plugs are counterfeit is that the screw holding the lid in place is not self-retaining (captive). BS 1363, the British standard for 13 A plugs, requires that the screw holding the two parts of the plug together is captive. On these plugs, the screw just falls out, it's not held in the base as it should be.
There is a Kitemark and licence number on the cover, implying BSI approval to BS 1363. However, the Kitemark print doesn’t look quite right, and the stated licence number (KM/09947) returns no match in the BSI certificate search. On that basis, this plug should be treated as counterfeit.
BSI Certificate SearchTwo other organisations are authorised to approve BS 1363 plugs, ASTA and Nemko. Both of these organisations also have a similar certificate search facility available on their websites.
The fuse in the plug is an obvious cheap counterfeit. It does not have a manufacturer's name or mark and is also missing an approval mark. Both are requirements of BS 1362, the British standard for plug fuses.
We can see that the fuse wire is trapped in place by the end cap on the fuse. A genuine BS 1362 fuse should have the fuse wire held in place by an eyelet within the cap.
Breaking the fuse open, we can see that it does not contain the sand filling required by BS 1362. The sand filling is important because it displaces the air within the fuse and prevents it from exploding when it blows. We also have an article on counterfeit fuses, including a video demonstration of a counterfeit fuse exploding.
The finish quality of the metal pins is noticeably poor.
If a plug is suspected to be counterfeit or non-compliant, it should be taken out of use immediately and replaced. This is part of managing electrical safety in the workplace. See our guide to managing PAT testing in the workplace.
Flammability Testing
To comply with BS 1363, the body of the plug must be made from a self-extinguishing material. To test this, we held a blow torch to the plug for a few seconds until a flame could be seen and then removed it. For self-extinguishing plastics, the flame should extinguish itself within 30 seconds of the ignition source being removed. The images below show the results. The flame did not extinguish itself, in fact, it intensified until the entire plug was well alight.
Comparison Test
In this example, we apply the same test to a genuine BS 1363 plug. The plastic melts, but it's impossible to ignite and produce a flame.
Conclusion
This flame test shows why counterfeit plugs are so dangerous. During PAT testing it’s not unusual to find overheated or melted plugs, often caused by loose terminals, poor connections or overloading. In many cases, the fuse may not operate immediately under moderate overload conditions, see our guide to plug fuse operation characteristics for an explanation of how fuse protection works. With a compliant BS 1363 plug, the casing material is designed to resist ignition and self-extinguish, which helps prevent a small fault turning into a fire. This counterfeit plug did the opposite and sustained a flame.
To reduce the risk of counterfeit electrical accessories entering the workplace, purchase plugs, fuses, chargers and adaptors through reputable supply chains and check that any claimed approvals are genuine. If in doubt, replace the item.
Identifying counterfeit and substandard electrical equipment is an important part of visual inspection and PAT testing, and it’s something we cover on our PAT testing courses. In this case, the key warning signs were the non-captive screw, the poor-quality fuse and the suspicious approval marking – although counterfeit products are not always this obvious.
For more examples found during PAT testing, see our page on counterfeit electrical equipment.