Common electrical tests include visual inspection, earth continuity test, insulation resistance test and leakage test. Correct training and good equipment helps to streamline electrical testing and minimize the risk of injury or death.
Most faults and potential problems are discovered through visual inspection. This may include pulling on leads or shaking, smelling, turning parts and tapping appliances.
The earth continuity test is essential for Class 1 appliances such as bench grinders and microwave ovens. These appliances typically have an earth, making them potentially dangerous if proper care, maintenance and testing is not performed. Apart from an insulation tester and multimeter, a portable appliance tester is be used for a comprehensive electrical safety test.
An insulation resistance test is done to expose weaknesses in insulation. PAT testers and insulation resistance testers are specifically designed for this purpose and help to indicate problems or weaknesses in voltage supply. Multimeters and ohmmeters are not designed to perform this kind of testing because they do not produce sufficient battery voltage.
The leakage test is used to fully inspect appliance circuitry. An RCD device is used during the leakage test to monitor the balance of current flow and shuts off power in the event of a leakage. This helps to minimize the risk of fatal electric shock during testing. Current leakage can occur as a result of faulty connections, frayed wiring or dampness.