PAT is an acronym for Portable Appliance Testing. It is a process which involves testing all electrical appliances,which can be moved, to ensure that they can be used safely. During PAT testing, appliances like vacuum cleaners, fridges, dishwashers, washing machines, microwaves and all other similar appliances are checked thoroughly for proper function. Cables and plugs around the appliances are checked and they are also checked for insulation and grounding. The tests are done within the building.