In a nutshell, Portable Appliance Testing (PAT testing process) starts with observation of a portable appliance, followed by a formal visual inspection. The final step is a formal inspection by a person or competent to perform the testing.
Step 1: Observation
Simple observation is the first and very important of the PAT Testing process. For example, if while using a kettle in the staff canteen you to notice that the plug is cracked, you should immediately let the office manager/safety officer know.
Step 2: 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 requires the competent individual to visually inspect the portable appliance and look for obvious defects such as frayed wires, cracked cables, and broken plugs. Most portable appliances with safety issues can be identified by implementing this step.
Step 3: 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. Each piece of equipment is 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 then 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 a PAT test?
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.