What is Portable Appliance Testing (PAT)?

Posted in Uncategorized
Published on August 1, 2019
Kiasu Workforce - Portable Appliance Testing

Portable Appliance Testing (PAT) is the periodic inspection of electrical equipment to identify defects. You’ve probably seen one of those little green stickers – likely on a toaster, kettle, washing machine or tumble dryer. It means the appliance has undergone electrical testing and is safe to use.

Is Portable Appliance Testing a legal requirement?

By law, electrical appliances in business premises must be safe for use (as per the Electricity at Work Regulations 1989). PAT testing allows businesses to comply with this legal requirement. There is no legal requirement to carry out PAT inspections at home, but it’s always worth keeping electrical safety in mind.

There are seven categories of appliance which should be considered for PAT testing:

  • Fixed equipment
  • Stationary equipment
  • IT equipment
  • Moveable appliances
  • Portable appliances
  • Cables & chargers
  • Handheld appliances

In this case, “moveable” means something which plugs into a socket, and can be unplugged and moved around easily. “Portable” means something designed for use on the go.

Most defects can be found by visual examination, but some types can only be found by testing. Visual examination is still necessary because some types of electrical safety defect can’t be detected by testing alone.

Visual inspection and testing by a competent person may be required, depending upon the type of equipment and the environment in which it is used.

How frequently do I need to test my electrical appliances?

Some appliances need to be tested more often, such as those which are well-used, often knocked or easily damaged. It is recommended that risk assessments are carried out regularly to determine how frequently each appliance should be tested, and the type of test needed.

The frequency of inspection and testing depends upon the type of equipment and the environment it is used in. For example, a power tool used on a construction site should be examined more frequently than a lamp in a hotel bedroom.

A record and / or labelling can be a useful management tool for monitoring and reviewing the effectiveness of the maintenance scheme – and to demonstrate that a scheme exists.

New equipment should be supplied in a safe condition and not require a formal portable appliance inspection or test. However, a simple visual check is recommended to verify the item is not damaged.

What are the classes of electrical equipment?

Electrical appliances are generally categorised as being in classes 1, 2 or 3, with Class 1 being the most dangerous and Class 3 the least dangerous. Class 1 appliances need a full PAT inspection, Class 2 appliances need an insulation test, and Class 3 appliances are safe enough not to require testing.

Class 1

This type of electrical equipment has only basic insulation and relies on an earth for protection. Examples include washing machines, tumble dryers, computers, kitchen equipment and extension leads.

Class 2

This type of electrical equipment has extra insulation and so doesn’t rely on an earth for protection, which makes it safer. E.g. lawnmowers, televisions, drills, hairdryers and lamps.

Class 3

Class 3 appliances, such as laptops, torches and cameras, are the safest class of electrical appliance due to the low voltages involved. Their charging leads may need to be PAT tested.

How is Portable Appliance Testing carried out?

Portable Appliance Testing

A level of knowledge and experience is needed to complete PAT testing. The right equipment is necessary, as is the ability to properly understand the test results.

Testing required depends on the type of appliance, and is subject to a risk assessment by the electrician to ensure it can be tested safely.

The order in which the tests are performed is important to the safety of the test operative. The sequence should always be:

  1. Earth continuity test
  2. Insulation resistance test
  3. Protective conductor/touch current test or alternative/substitute leakage test
  4. Functional Check

An insulation test should always come before attempting any tests which involve applying mains power to the equipment under test, as it may detect a dangerous insulation failure.

The recommendations given by IET Code of Practice for In-Service Testing of Electrical Equipment are as follows:

Class I Appliances

  1. Earth continuity test
  2. Insulation resistance test or protective conductor current test or alternative/ substitute leakage test
  3. Functional checks

Class II Appliances

  1. Insulation resistance test or touch current test or alternative/substitute leakage test
  2. Functional checks

Can I carry out PAT inspections myself?

Testing can legally be carried out by a “competent person”. This person should have adequate knowledge of electricity and experience of electrical work. They need to know how to carry out the visual inspection & PAT test, as well as understand the hazards involved.

They should also know the precautions to take when PAT testing and be able to decide whether it’s safe for PAT testing to continue.

It may make sense to contract a qualified electrician to carry out PAT procedures, especially where there are multiple items or class 1 appliances which require testing.


Article by Barney Scott, Kiasu Group

© 2019 Barney Scott, Kiasu Group