Are Overload Tests to Become Part of the BS136-1?

Overload tests for plugs are set to become a part of the 2012 BS1363-1 specification for rewirable and non rewirable 13A plugs.

The ESC conducted an investigation in 2010 on the overloading of four-way extension leads. The investigation found that it is possible to overload extension leads causing dangerous conditions, and the 13amp plug is the weakest component.

Most of the plugs in the test showed damage from overheating after being overloaded. With some of the plugs reaching shocking surface temperatures of up to 200°C, it is not surprising that the plugs showed signs of damage. This obviously then puts users of the plug at risk of electric shock. One of the samples even left the conductor pin in the socket outlet when removed from the mains.

The problem with these results is that it is very easy for standard users in homes and businesses to overload extension leads through the use of high current appliances plugged into the same extension cable.

Since this test was conducted, ESC has been able to get the BSI Technical Committee to agree in principle that overload testing during product manufacture is necessary.

If these standards do become required, PAT technicians may see less damage to cables and extension leads from overloading.

Even so, it is still important to get clients to realise how dangerous overloading is. Let us know if you’ve had any jobs where extension leads have been damaged due to overloading.

Written by Sara Thomson