The SLP (Surface Leakage Protection) invention won the Silver Prize at the 40th World Exhibition of Invention, Geneva, April 2012 and is going to market. Next year the Chinese customer will be able to purchase wash machine facilitated with SLP device, and enjoy the benefit of safety by SLP.


Introduce SLP

The world’s first electrocution protection device was developed in 1955 in South Africa gold mines where electrical hazards were of great concern. Following the accidental electrocution of a woman in a domestic accident at the Stilfontein gold mining village near Johannesburg, a few hundred electrocution protection units were installed in the homes of the mining village during 1957 and 1958. Nowadays, many countries such as Australia, Germany, Norway, United Kingdom, Canada, and USA have rules and regulations making the use of electrocution protection device mandatory in houses or on sockets.
Currently available electrocution protection devices are all of a RCD (Residual Current Device) that operates by measuring the current balance between two conductors. If the current flowing out the live conductor and that returning through the neutral conductor do not sum to zero, there is a leakage of current to somewhere else (to earth/ground, or to another circuit), and the RCD will open its contacts.
Originated from the gold mine application, RCD brings weak points that limit its application. The problem with a RCD is that of false trips caused by uncertainty of the current leakage a power distribution system or an appliance may cause. For example, a poor insulated cable of a power distribution or an appliance such as a water heater may cause current leakages that are common and not a cause of injury or mortality, but may be a cause of nuisance trip of a RCD.
Another problem is that if a single RCD is installed for an entire electrical installation, any fault may cut all power to the premises.
The most serious weak point of RCD was ignored for a long time: RCD must be tripped by a leakage current flowing through a person body. It may be due to we have no other solution better than RCD. Image that you are invited to have a current that may kill you, flow through your body and a device will stop the current within 25-40 milliseconds, before electric shock can drive your heart into ventricular fibrillation. Will you accept the invitation with pleasure?
Now and here, in this Great Miner website, we are pleasure to announce the realization of SLP (Surface Leakage Protection), an invention made by Dr. Wei Wu, which overcomes many weak points of RCD mentioned above.
A SLP device can disconnect the power from an appliance where the current leakage happens due to poor insulation, before a person body touches the appliance, so that is fundamentally safe. It can also protect the current leakage caused by power line connection errors and caused by other power system for those a RCD fails to function.

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