There are many types of electrical equipment that can be tested. They can be classified into:
Class 1: Along with single insulation, these appliances use a protective earth conductor to protect the user from electric shock. Class 1 appliances usually have exposed metal parts, eg Kettles, irons and toasters.
Class 2: These appliances are known as double insulated, as they have no earth conductor, but can still protect you from electric shock. Class 2 appliances are encased with non-conductive materials such as rubber or plastics, eg hair dryers, lamps and electric drills. To find out if your appliance is a class 2, check the casing for a 'square within a square' symbol. This mark signifies a double insulated appliance.
3 Phase: The major difference to single phase appliances is clearly visible. They have much larger plugs and sockets, with either 4 or 5 pins. These are tested in the same manner as class 1, and are conducted for each phase.
RCD's: RCD's are tested to ensure they trip within the maximum trip time. This test is conducted twice as per the minimum requirements of AS/NZS3760:2010. Testing of the trip button will also be conducted to ensure correct operation.