How to use a PAT Tester: A Step by Step Guide

PAT testing – also known as Portable Appliance Testing – refers to the examination of portable electrical appliances and equipment to determine they are safe to use in a work environment. 

Electrical equipment that is faulty or poorly maintained can result in burns, electric shocks and fires. PAT tests are a cost effective and simple method to ensure there is no risk to users from electrical equipment. 

There are usually three steps included in using a PAT Tester – informal regular checks by the user, a formal visual examination of the equipment and using a portable appliance tester device to perform a manual inspection of the equipment. 

Step 1 – Checks by the user

Anyone who makes use of electrical equipment should have some level of basic training in how to use it in a safe manner and danger signs to look out for during their induction process. Users need to have confidence in their ability to regularly make visual inspections of the equipment to spot any obvious damage, as well as to notice potential risk factors such as water hazards or cables stuck under desks. 

Step 2 – The formal visual inspection

Formal visual inspections can normally detect up to around 90% of any potential problems with a piece of electrical equipment and they should be performed by either a professional or a competent staff member with the correct training. 

The equipment should always be turned off and unplugged prior to commencing the visual inspection. The checklist needs to include the plug, the cable, the mains socket, RCD checks and an environmental check.

The plug should be checked for any sign of damage such as bent pins, burns or cracks, while ensuring the wiring is correct. Earth, live and neutral conductors all need to be tightly connected to their appropriate terminals. 

The cable should be physically and visually checked for damage such as abrasions, cuts and fraying with any exposed wiring meaning the equipment has immediately failed inspection. 

The appliance should be inspected for obvious damage such as burns, corrosion, cracks and wear and tear on the casing. 

The mains socket should receive a visual inspection even though it is not technically included in a PAT test. A fixed wire test is used to test mains sockets for cracks, loose fittings and signs of overheating. The shutter mechanism should also be checked. 

Residual Current Devices (RCD) feature a test button and trip in the event that the current that flows through the live conductor differs from that of the neutral. Checks should be carried out to check the operating current, ensure the test button is in working order and look for any damage. 

Environmental checks look for cable trip hazards, fire hazards, overloaded extension leads and water damage. 

Step 3 – The PAT Test

The PAT tester carries out a visual inspection in addition to a manual electrical examination with the use of a portable appliance tester device. The appliance is tested for earth continuity, insulation resistance and lead polarity, and more. The appliance will either pass or fail, with failed appliances to be immediately removed from use. 

PAT tests are strongly recommended for any business that makes use of portable electrical equipment such as offices, landlords, manufacturing, restaurants and hotels, and construction.