How to perform pat testing on all electrical equipment

Why PAT testing is essential for your trade

To work safely and professionally, you must ensure all your corded electrical equipment—from drills to extension leads—undergoes Portable Appliance Testing (PAT). In the UK, the Electricity at Work Regulations 1989 require that any electrical equipment that has the potential to cause injury is maintained in a safe condition. Most construction sites and commercial clients will refuse you entry unless you can provide a valid PAT testing certificate and show 'pass' stickers on your gear.

What needs testing?

Essentially, any item with a plug that is portable or can be moved while connected to a power supply needs testing. In a trade environment, this typically includes:

• Power tools such as drills, saws, and grinders.
• Extension leads and cable reels.
• Battery chargers for cordless tools.
• Site lighting, transformers, and 110v equipment.
• Kettles or heaters used in site offices or vans.

How to complete the task

1. Identify a competent person: While you can take a course to test your own equipment, most small business owners hire a qualified electrician or a specialist PAT testing company. Ensure they use calibrated testing equipment.
2. Gather your equipment: Collect all your tools and leads in one place. Don't forget the items tucked away in the back of the van or in your home office.
3. Visual inspection: The tester will first check for frayed cables, cracked plugs, or signs of overheating. A significant percentage of faults are found during this visual stage.
4. Manual testing: The tester will use a PAT device to check for earth continuity, lead polarity, and insulation resistance. This identifies internal issues that aren't visible to the eye.
5. Apply labels: Every item that passes must be labelled with a 'Pass' sticker showing the test date and the date the next test is recommended. Any items that fail should be clearly marked and removed from service immediately for repair or disposal.
6. Request your certificate: Once the testing is complete, you must receive a formal 'Portable Appliance Testing Report' or certificate. Keep a digital copy on your phone or in your van to show site managers when requested.

Best practices for tool safety

Relatable Tip: Treat PAT testing as an annual 'MOT' for your tools. Even if an item looks fine, heavy site use can cause internal wear. Identifying a fault during a test is much safer than finding it via a blown fuse—or an electric shock—while you are halfway through a job.

While the law doesn't specify exactly how often you should test, the Health and Safety Executive (HSE) suggests frequencies based on the risk and environment. For tradespeople working on construction sites, testing every 3 to 6 months is often recommended due to the harsh conditions.