Portable Appliance Testing (or PAT Testing) is a legally required method of testing portable appliances. There are many stages that go towards the testing process. It will end with either a pass or fail result.
Portable Appliance Testing needs to look at certain safety elements. Amongst the things that can cause the failure is damage to cables, plugs and wires, overheating and signs of water damage. There should be no bare wires and no sign of internal damage.
The testing needs to be done according to the IEE (Institute of Electrical Engineers) guidelines. Before testing takes place anyone who is not part of the testing team should leave the premises.
The most basic part of the testing process is the visual inspection. Over 90% of problems are said to be found during this part of the process. It consists of the tester looking at the appliance and seeing if there are any obvious issues.
Here the tester will be able to see any poor wiring, cracked casing, bent pins and other damage. These are the most basic areas where appliances fail the PAT test.
The location that a particular appliance is used needs to be inspected. There must be sufficient ventilation (depending one the needs of the equipment), the area cannot be unreasonably damp, and controls to the equipment must be easily accessible.
An Earth Bond Test needs to be carried out during the testing process. Electrical Test Equipment is necessary for this part of the procedure. This is a test between the earth bond and continuity between the plug pin and external components. The voltage and test current is assessed during this process.
Other parts of the test are the insulation test and operational test.
The insulation test is necessary to ensure the insulation resistance is safe. The operational test simply consists of the tester switching the equipment on and testing out certain regular functions that it should perform, and making sure its performance is as expected.
Once testing has been completed the result of the PAT test should be clearly stated. The most common method of this is simply placing a label on the equipment. The label will say whether the appliance has passed or failed, and should also include more specific details of its condition. It will give the date of the test and the date at which another test will be necessary.
Equipment that is faulty or damaged should be removed from service immediately. It can then be determined whether or not the seriousness of the damage is sufficient for the equipment to be out of use.
PAT testing records are required to be kept for the duration of the life of the appliance. This is a legal necessity as it shows that tests have been carried out and the results of them.