The basics of Portable Appliance Testing
UK-Disco Home About UK-Disco List Your Details Other Links Frequently Asked Questions Contact Us Bookmark Us
UK-PAT : The Directory of Portable Appliance Testers

Portable Appliance Testing Basics

Code of Practice for In-service Inspection and Testing of Electrical Equipment

Portable Appliance Testing

Each and every business in the UK needs to be in compliance with the Electricity at Work Regulations. Portable Appliance Testing (or PAT Testing) is the best way for companies and landlords to comply with the law.

Portable Appliance Testing can be broken down into a three-step process.  The PAT process starts with simple observation of a portable appliance, followed by a formal visual inspection, and then finally a formal hands-on inspection by a person or company competent to perform the testing.  

Simple Observation

The first step is for staff to simply look at any portable appliance they will be using and make known any electrical safety issues they may believe it has.  For instance, if you are using a kettle in your workplace, and one day you happen to notice that the plug is cracked, you should immediately let your superiors know of the issue. 

Simple observation is a very important part of the PAT process and should always lead to steps two and three of the process: formal visual inspection and the combined inspections and PAT testing, both to be performed by a competent individual.

Formal Visual Inspection

All portable appliances in the workplace, or which are made available to the public for their use, should undergo the process of a formal visual inspection by a competent individual.  For an individual to be considered 'competent' they should have some basic training in portable appliance testing.

The formal visual inspection allows the competent individual the time to visually inspect the portable appliance and look for obvious defects such as frayed wires, cracked cables, and broken plugs.  Interestingly enough, approximately 90% of portable appliances with safety issues can be identified simply through this set of the process. 

Combined Inspections and PAT Testing

The third and final step in the PAT process is the formal hands-on inspection and testing, carried out at regular set intervals. The frequency of formal PAT Testing varies depending on the piece of equipment being tested and the environment in which it is operated. 

Each piece of equipment will be tested in isolation, i.e. the appliance will be disconnected from the mains supply and all data cables will be removed.

The competent individual will perform a number of checks, including:

  • Checking for damage to the outer portion of the power cable
  • Damage to the plug itself
  • Any area on the cable where tape has been applied
  • Signs of misuse or over usage of an item, such as rusting or smoke damage
  • Loose parts or screws which effect the appliances working ability or safety
  • Removal of the plug cover to inspect for: adequate fuses, cord grip security and integrity, three wires connected to the correct terminals, no bare wires visible, tight terminal screws, and that there is no sign of damage, overheating, wetness, and excessive dust or dirt.

Depending on the type of appliance, the PAT tester will then continue with a variety of formal safety tests, using a specialist piece of equipment. This can include:

  • An Earth Bond Impedance Test
  • Insulation Resistance Test
  • Load Test
  • Operation Test

What happens if an appliance fails any of the PAT tests? This will depend on the nature of the failure and the arrangement you have with the PAT tester. Simple faults may be rectified or damaged items replaced, allowing the equipment to be re-tested and passed. A more serious fault will mean the appliance must be taken out of service and either properly repaired of safely and legally disposed of.

PAT Testing Stickers

An appropriate 'Pass' or 'Fail' sticker will be fixed to the appliance to indicate the test result. These labels, (sometimes tamper-proof), are usually applied to the plug in such a way as to prevent the socket from being opened without breaking the label.

Find a PAT tester in your area

If you have electrical equipment that requires PAT testing, use our PAT testing directory to locate an appliance tester in your area.


Useful Articles

PAT Testing Stickers
Portable Appliance Testing Basics
What is PAT Testing
Portable Appliance Testing Books

Need a PAT Tester? Search our database of PAT testing companies