Portable Appliance Test

In the United Kingdom, Portable Appliance Testing is a process by which electrical appliances are routinely checked to see if they are safe.

When people work with electrical appliances, Health and safety regulations say the appliance must be safe. Testing should be carried out at regular intervals to ensure continual safety; the interval between tests depending on both the type of appliance and the environment it is used in.

Many people will have seen evidence of portable appliance testing in the little labels stuck to power cables around their offices.

Many people assume (incorrectly) that all appliances have to be tested every year, but this is not the case. All that (British) law requires is that the appliances are safe (as far as is reasonably practicable.) However, guidance from the Institution of Electrical Engineers (IEE) and the Health and Safety Executive (HSE) suggest intervals for inspection and testing, ranging from 3 months (for construction equipment) to 4 years (computers in offices.)

Portable Appliance Testing is abbreviated to 'PAT.' The phrase 'PAT Testing' is in fact a tautology in the same way that some people say 'LCD Display' However, the phrase is commonly used in the industry even though most people realise it is incorrect. The correct term for the whole process is 'In-service Inspection & Testing of Electrical Equipment'.