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.