The process of PAT Testing is made easier if you understand what is trying to be achieved. An item of electrical equipment will normally be subjected to 4 different types of testing during its lifetime:
Usually to check it conforms to the relevant safety standards.
Appliance tested by manufacturer before it is packaged up and sold.
Carried out if appliance is refurbished or repaired at any point.
IN-SERVICE INSPECTION & TESTING
Also known as Portable Appliance Testing.