Testing and Tagging of electrical equipment must be carried out by a “competent person”. Under the Act, a competent person is defined as a one who has completed the necessary practical and theoretical skills, acquired through training, qualification, experience or a combination of these. In some states, completion of a nationally recognised competency based training course is also a requirement, as is the use of a Portable Appliance Tester (PAT).
The current Australian Standard, AS/NZS 3760:2003 specifies the tests required to be conducted in order to confirm the electrical safety of an item. These include the following:
Insulation Resistance
This test checks for the integrity of the insulation that is protecting users from the live parts within the appliance. In the majority of cases, an Insulation Resistance Tester, or PAT is used to complete the insulation resistance test on an appliance. The Australian Standard states that testers must have an accuracy of +/- 5%. Most modern equipment contains a soft switch which requires current to be applied to the item in order for it to be tested. As such, this requires a Leakage Current Test.
Leakage Current Testing
This test requires the equipment to be connected to a power source and measuring any current leakage. To conduct this test, the tester must be connected to the mains power. A mains power PAT or an alternative leakage current tester needs to be used.
Polarity
A polarity test is conducted on flexible supply cords with a to ensure the active and neutral wires are connected to the correct terminals. This test requires the use of a Multimeter, Insulation Resistance Tester, or PAT. Whilst testing polarity, we also test for short circuits between conductors.
Earth Resistance
An earth resistance test confirms whether the earth connection of the equipment is less than 1 ohm. The earth continuity is tested between the plug and exposed external metal parts, or the plug and the socket. One method of testing this is to conduct an earth continuity test. The test can be conducted using a PAT, Multimeter or Insulation Resistance tester. We recommend an earth bond test be conducted using a PAT capable of applying higher currents to determine if the equipment can handle a fault current correctly, and to measure earth resistance.
Visual Testing
Approximately 90% of faults are identified from visual inspection prior to the completion of the required electrical tests. A visual inspection involves a comprehensive inspection of flexible supply cord, plug, equipment, socket, covers and guards. Equipment is checked for rattles indicating the presence of foreign objects that may interfere with electrical safety. Class II appliances are checked for deep engraving which may impact on insulation.