HomeHow Often Should PAT Testing Be Done? A Risk Assessment Guide
How often PAT testing should be carried out depends on a suitable risk assessment. The right inspection and test interval is determined by the environment, the equipment type, the way it is used, who uses it, and what you have found previously. Most organisations have a mix of locations and risks (for example, a hotel will typically have a kitchen, bedrooms and an office), so the frequency is often different for each area. Regular inspection and testing reduces risk, but it cannot prevent damage from occurring. The aim of the risk assessment is to set sensible inspection and test intervals and to identify where additional control measures are needed.
Assessment Factors
Equipment type - Some equipment is more likely to be damaged than others. Small portable items are frequently moved and are more likely to be dropped. Large stationary appliances are rarely moved and are generally lower risk. An electric shock from hand-held equipment is often more serious because the fault current is more likely to pass across the heart.
See also: equipment types.
Environment - The environment affects both the likelihood of damage and the consequences of a fault. Equipment used on construction sites or in workshops is more likely to be damaged than equipment used in an office. In wet or damp locations, the potential severity of an electric shock is higher.
Users - Trained and informed users are more likely to spot damage and report it quickly. Children, members of the public and untrained users may not recognise hazards or may continue using damaged equipment. For some user groups (including children and the elderly) the consequences of electric shock are more severe.
Equipment construction - Fault protection for Class I and Class II electrical equipment works differently. Class I equipment relies on an effective earth path; if the earth connection is missing or compromised, safety is reduced. Class II equipment uses double or reinforced insulation and does not rely on an earth connection. For this reason, a Class I appliance is generally higher risk than an equivalent Class II appliance.
Frequency of use - Equipment that is used frequently is more likely to suffer damage than equipment that is used less often.
Previous records - Previous inspection and test results may show which equipment is most susceptible to damage. Patterns may relate to certain equipment types, environments, or user groups.
Electrical installation - Circuits without RCD protection are generally higher risk (depending on the equipment and environment). For fixed machinery, the position of isolators, cable management and the likelihood of mechanical damage should also be considered.
Control Measures
User checks - Many faults are found by a simple external visual check. The user is often most familiar with the equipment and is best placed to spot damage early and report it. User checks normally cover obvious issues such as a cracked case, damaged cable, loose parts and signs of overheating. Recording faults helps identify repeated problems and areas where extra controls are needed. See our separate guide to user checks.
Inspection and testing - A formal visual inspection includes a detailed examination of the equipment, including opening the plug to check wiring, connections, fuse and cable grip. Electrical testing can identify faults that cannot be found by inspection alone, such as a disconnected protective conductor. If you need to train someone to carry this out in-house, see our PAT Competent Person course.
Alternative Equipment - Increasing the frequency of inspection and testing will not prevent damage from occurring if the equipment is unsuitable for the environment or its use. Where recurring damage is found, the equipment may need to be replaced with a more rugged type, or substituted with a less dangerous alternative. For example, 230V mains powered hand tools may need to be replaced with battery-powered, air-powered or 110V equivalent types.
Residual Current Device (RCD) - An RCD rapidly switches off the supply if it detects a fault, reducing the potential for injury. RCDs do not detect all faults and should only be used as a secondary means of reducing the risk. Ideally, the RCD should be built into the distribution board. If this is not possible, sockets incorporating an RCD, or an RCD plug adaptor, can be used to provide additional protection.
Example Risk Based Assessments
A risk assessment can take many different forms, but essentially it is a process of evaluating the potential risks and then deciding on suitable control measures needed to reduce, minimise or eliminate any risk. The risk assessment should be regularly reviewed to ensure that the measures taken are effective and to check if there have been any changes that would affect the assessment. The Health and Safety Executive (HSE) have detailed information on creating a risk assessment.
The examples below show a basic form of risk assessment to determine a suitable frequency for the inspection and testing.
| Service Engineers Van Tools & Equipment | |
|---|---|
| Environment | High Risk. Tools are used on customers premises. They are sometimes required to be used outdoors |
| User | Staff are technically competent but they have not received any training on carrying out electrical safety checks |
| Equipment Type & Construction | Mostly hand-held Class II power tools. There are also some Class I extension reels and each van has a Class I compressor |
| Frequency of Use | Hand-held tools and extension reels are moved in and out of the work vans daily |
| Electrical Installation | The equipment is mainly used on customers premises, which may not necessarily have circuits with RCD protection. |
| Previous Records | PAT testing is currently carried out every 12 months. Records of previous PAT testing show a high percentage of failed equipment. Most equipment is failing due to damaged cables. |
| Decision | Previous records show that equipment is regularly failing the visual inspection, so the frequency of formal visual inspections should be increased to every 3 months. The combined inspection and testing should remain at 12 months as the records do not show a history of equipment failing the electrical tests
Previously damaged equipment has only been identified during the annual PAT testing, so in addition, the users should be given training to carry out daily user checks and a system for reporting damaged equipment should be implemented. Hand-held tools should be replaced with battery-powered alternatives, where suitable equivalent tools are available. All remaining tools that can not be replaced with battery-powered equivalents, should be fitted with RCD plugs All Class I and Class II equipment - formal visual inspection every 3 months All Class I and Class II equipment - combined inspection & testing every 12 months |
| Office | |
|---|---|
| Environment | Low Risk. Mostly IT equipment that is very rarely moved. |
| User | Staff have been trained to carry out basic safety checks on electrical equipment. Training is updated annually. Staff are not allowed to use personal electrical appliances at work. |
| Equipment Type & Construction | Mostly a mixture of Class I and Class II IT equipment. There are also some extension leads, lamps and desktop fans. There are also several Class I heaters that are fixed to the wall and wired to a fused spur outlet. |
| Frequency of Use | Daily |
| Electrical Installation | All the electrical circuits within the office have RCD protection at the distribution board. The building's fixed wiring is inspected and tested every 5 years. |
| Previous Records | PAT testing is currently carried out every 12 months. Previous inspection and test records show no history of any damaged equipment being found. |
| Decision | Previous records show that there has been no history of equipment failing during the PAT testing. The staff are diligent at carrying out user checks. The office equipment is rarely moved, so the risk of damage is low. The majority of the IT equipment is regularly replaced every 4 - 5 years. All circuits have RCD protection.
Class I equipment - Combined inspection and testing every three years. Class II office equipment - formal visual inspection every three years, testing not required. Class I wall heaters - To be inspected and tested every 5 years during the inspection and testing of the building wiring. |
There are also a number of similar sample risk assessments available in the IET Code of Practice for In-Service Inspection and Testing, 5th Edition.
HSE guidance
The HSE publish guidance on the frequency of testing and a table with suggested initial maintenance intervals in their publication Maintaining Portable Electrical Equipment.
Guidance on the Initial Frequency of Inspection and Testing
The table below provides some guidance on the initial frequency of the inspection and testing. This table is not intended to replace a risk assessment, rather it is intended to help the duty holder decide on a suitable frequency following the risk assessment. This is probably most useful where PAT testing has not previously been carried out, in which case, the table provides a good starting point.
Class I Formal Visual Inspection |
Class I Inspection & Testing |
Class II Formal Visual Inspection |
Class II Inspection & Testing |
|
|---|---|---|---|---|
| Offices & Shops | ||||
| Stationary equipment | 24 months | 60 months | 24 months | none |
| IT equipment | 24 months | 60 months | 24 months | none |
| Movable equipment | 12 months | 24 months | 24 months | none |
| Portable equipment | 12 months | 24 months | 24 months | none |
| Hand-held equipment | 12 months | 24 months | 12 months | none |
| Fixed | 24 months | 48 months | 24 months | none |
| Hotels | ||||
| Stationary equipment | 24 months | 60 months | 24 months | none |
| IT equipment | 24 months | 60 months | 24 months | none |
| Movable equipment | 12 months | 24 months | 24 months | none |
| Portable equipment | 12 months | 24 months | 24 months | none |
| Hand-held equipment | 12 months | 24 months | 12 months | none |
| Fixed | 24 months | 48 months | 24 months | none |
| Equipment used by the public | ||||
| Stationary equipment | 1 month | 12 months | 12 months | 24 months |
| IT equipment | 1 month | 12 months | 12 months | 24 months |
| Movable equipment | 1 week | 6 months | 6 months | 12 months |
| Portable equipment | 1 week | 6 months | 6 months | 12 months |
| Hand-held equipment | 1 week | 6 months | 6 months | 12 months |
| Fixed | 12 months | 36 months | 12 months | 36 months |
| Industrial including commercial kitchens | ||||
| Stationary equipment | None | 24 months | None | 24 months |
| IT equipment | None | 24 months | None | 24 months |
| Movable equipment | 6 months | 12 months | 6 months | 24 months |
| Portable equipment | 6 months | 12 months | 6 months | 12 months |
| Hand-held equipment | 6 months | 12 months | 6 months | 12 months |
| Fixed | 12 months | 24 months | 12 months | 48 months |
| Schools | ||||
| Stationary equipment | None | 12 months | 12 months | 48 months |
| IT equipment | None | 12 months | 12 months | 48 months |
| Movable equipment | 6 months | 12 months | 12 months | 48 months |
| Portable equipment | 6 months | 12 months | 12 months | 48 months |
| Hand-held equipment | 6 months | 12 months | 12 months | 48 months |
| Fixed | 12 months | 36 months | 12 months | 48 months |
| Construction sites 110V equipment | ||||
| Stationary equipment | 1 month | 3 months | 1 month | 3 months |
| Movable equipment | 1 month | 3 months | 1 month | 3 months |
| Portable equipment | 1 month | 3 months | 1 month | 3 months |
| Hand-held equipment | 1 month | 3 months | 1 month | 3 months |
This table is based on guidance originally published by the IET in the Code of Practice for In-Service Inspection and Testing of Electrical Equipment. It was subsequently removed from the Code of Practice with the publication of the 5th edition. We also provide a copy of the initial frequency table in our PAT training course manual.