Earth Leakage

[Leecatt]

A common problem with random tripping, surge protection plug tops, they break down under load and cause random tripping.

Another common problem, cut insulation on surfix, I have found insulation cut where the electrician strips the cable and doesn't use tape, it gets moisture in the cut and cause nuisance tripping.

In fact there are so many, a good electrician will identify the problem and repair it and others will find other means to overcome the problem, bypassing a stove is one of the common remedies.

This house had various areas from where there were earth leakages. Some where electronic equipment, slight leakage at geysers and borehole pumps and various flourescent lights. Too many to mention here. Eventually it exceeded the 21 milliamps the earth leakage worked at or perhaps the unit had become more sensitive over time, and the only alternative was to raise the threshold of the earth leakage unit.

It is incorrect to remove a stove from the earth leakage protected circuit unless it is connected via a "stove coupler"
See 6.16.3.3 Stove connection.

[AndyD]

It's getting more and more common nowadays where the global cumulative leakage in a house exceeds the 20-30mA tripping threshold. Computers have an acceptable leakage of 1-3mA because of their built-in surge arrestors, same with many switch-mode power supplies like laptops, phone and battery chargers etc. Many people don't understand that the earth on majority of circuits is functional and not only there to prevent shocks through elevated touch voltages. Having a standing leakage of 10-15 mA isn't unusual and it doesn't leave much room for very minor fault currents that wouldn't otherwise be a problem.

Often the only solution is to spread the load through more than one RCD (earth leakage). Pretty soon each circuit should have its own RCBO which is a much better system than just one or two RCD's.



RCBO's are still coming down in size and in price but it would be good practice to install them on the socket circuits if you can fit them in the DB.

[ians]

If the stove is connected to an isolator, there is no need to connect it to earth leakage (we don't use stove couplers in Durban) The only time you have to connect it to earth leakage is when the isolator has a combo isolator socket outlet, like we had in the old days.

[ians]

Andy if anything I do believe in this country, I could see less being connected to the earth leakage rather than more earth leakage units being installed