A guide to portable appliance testing

PAT’s or Portable Appliance Testing should be carried out on all portable electrical items in the workplace. It is a requirement of Health and Safety legislation to ensure that appliances are tested either each year or every two years depending on the appliance, and there are guidelines to follow for all appliances. This article provides you with a guide to portable appliance testing.

In the workplace, it is essential that all appliances that are plugged into the electrical supply are checked regularly with a PATs machine. Seaward are the most well known manufacturers of such equipment, and reliability and accuracy are very important.

Earth leakage test

The machine carries out standard electrical tests on the appliance to check the insulation between the conductors of the mains cable and that the appliance is appropriately earthed to prevent electric shock to the user.The test also records the leakage current to earth, because if this value exceeds 30mA, the appliance would fail the earth leakage test.

Examine the power plug

An earth leakage current of 50mA can potentially be fatal to anyone in contact with the faulty appliance. The power plug should also be examined to ensure that the correct value of the fuse has been installed for the current rating of the appliance, and to check that the plug is wired correctly.

The primary function of PATs testing is to prevent accidental electric shock from portable appliances, which by their nature are often moved around into different environments, and hence damage can sometimes occur.

Portable appliances cover just about anything from an electric kettle to a fridge, from a desk lamp to a shredder, Microwave, electric drill, computer, the list is endless.

Appliances that are a particular hazard are those with metal components or cases that the user can touch, and that is why many modern pieces of equipment are designed to have moulded plastic cases so that there are no metal surfaces for a user to touch, and therefore the risk of an electric shock is reduced if an appliance becomes faulty.

When an appliance is tested and passed, the data from the test is recorded and the appliance is given a unique identification number. This can then be used in subsequent years to re-test the appliance.

The person testing the appliance is taking responsibility for the test being completed correctly. It is important that all appliances be tested by competent, and appropriately trained electrical personnel with recognised training credentials. Seaward offers training courses in the UK, and other regional establishments will also offer accredited PAT’s training courses.