All PAT testing is carried out under the IEE’s Code of Practice for in-service inspection and testing of electrical equipment.
The first element in the Portable appliance testing process is the visual inspection.
A careful assessment is made of the physical condition of the plug, flex, casing, switches and the environment the appliance is operated in.
The second element is the Electrical Tests.
These tests are carried out using dedicated, specialist equipment designed to test for potentially dangerous faults that may exist within the appliance.
These tests fall into three categories:-
The first is to test the quality of the Earth Bond within the appliance and the cable on Class 1 appliances.
These tests ensure the system, designed to protect the user from serious electric shock, is in good condition.
Failure of the earth bond could result in an electrical shock being substantially more serious as well as making the appliance a considerable fire hazard.
The second group of tests assess the quality of the insulation within the appliance .
These tests are particularly useful, not only because they assess the safety of the appliance at that moment in time, but also when the detailed history of consecutive insulation readings are examined, the rate of deterioration can be seen and a judgment made to replace the appliance before it becomes unsafe.
The third group of tests are not compulsory.
The Operational or Load Test is sometimes useful to ascertain the power consumption of an appliance. (information that could reveal certain faults within the appliance).
The Dielectric Strength Test or Flash Test is not commonly used, as the very high voltages involved can damage some electrical systems and totally destroy others, and so is generally only used in manufactures type testing and after certain types of appliances are repaired.
The Earth Leakage Test is again sometimes useful in particular circumstances.
Following these tests, a label is attached to the appliance indicating its pass or fail status. All labels contain a unique number to identify each appliance within your company. The label also gives information about the test date, engineer’s ID and the re-test date. This, therefore, gives you a quick visible means of identifying an appliances test status.