Test for electrical faults

Many homeowners are not aware that an earth leakage switch needs to be tested on a regular basis to ensure the system is working properly, especially in an older home.

Take a look at your main distribution board and identify the earth leakage switch. In most cases you will notice that the switch is labelled with an instruction to test regularly. Testing ensures that the switch operates properly by tripping the circuit breaker (main switch) on the distribution board. The purpose of an earth leakage switch is to ensure that the distribution board and home electrical supply works properly and acts as a safety precaution in the event of a fault.

Testing an earth leakage switch

Be sure to switch off all appliances beforehand and do this test during daylight hours. To test the earth leakage switch press the ‘test’ button. Once pressed, the device should automatically switch off the electrical supply – the same as it would do if an earth leakage fault develops. If the device does not switch off the electrical supply, contact a qualified electrician immediately.

Take a look at your distribution board

Every homeowner should have a fair understanding of their distribution board. On the main board there are individual switches for the geyser, stove, lights and plugs, as well as separate switches for larger appliances such as a pool heater o, home security system. There may even be separate switches for outdoor electrical lights and power points. Each switch on the distribution board is rated for an allocated amount of current. A 15 amp switch, for example, protects a 15 amp flow of current and, similarly, a 20 amp switch protects a 20 amp flow of current. When the rated current increases above the allocated amount, the switch trips and breaks the circuit. This method protects your home from electrical fire.

Switches keep tripping

• Overloading a power outlet or plug point can be a common fault for a switch that trips. If you have too many appliances on one plug point and all the appliances are switched on at the same time, the circuit breaker trips to prevent overheating of the circuit.
• A faulty appliance can cause a switch to trip.
• A short circuit caused by one wire touching another wire, either in an appliance or in the wiring of a home, will result in a tripped switch. In an older home where electrical wiring is not routed through pipes or channels, the outer protective insulation can be damaged by rodents or become brittle with age and crack, causing wires to touch each other.
• Where plug or power points are placed on the exterior of a home, check that the housing is still watertight, as moisture can cause these to trip.

Should you suspect that the wiring in your home is faulty, immediately call a qualified electrician to inspect and rectify the problem. Under no circumstances should you attempt to repair faulty wiring other than that of an appliance.

Fault finding

If you are unable to identify the problem you may need to do some fault finding. Here are a few hints on how to go about fault finding for home electrical supply:

• Unplug all the appliances in your home
• At the main distribution board reset the circuit breaker - switch off and on again, or switch on if it has tripped.
• If the switch trips and there are no appliances switched on the short lies in the house wiring. This may be in the circuit breaker panel itself, or at an individual plug point.
• If the circuit breaker does not trip, go back to the plug points and start adding a single appliance to each point – turning on the circuit breaker each time as you move around the house.
• If the switch still has not tripped, the problem could be caused by a specific appliance.
• Systematically plug each item into the outlet until you find the faulty appliance.

If all else fails it's time to call for a qualified electrician to take inspect and determine the problem.