Installation, Inspection and Testing

A periodic Inspection is a test and inspection to ascertain the condition of an existing electrical installations, to identify (in order of priority) any deficiencies against BS7671: which is the British standards for electrical installations formerly known as the IEE's Wiring Regulations, the most recent version of which came into force in July 2018 and which is the 18th Edition of this document.

All non-domestic electrical installations should be subject to a regular programme of testing and inspection to comply with current legislation. You must ensure that all necessary precautions are being taken to reduce the risk of injury or death through electrical failure.

There are many good reasons for adopting periodic testing. You may need to inspect and test to comply with the IEE Wiring Regulations 18th Edition. Or if you have recently acquired ownership or tenancy of business / workplace premises you may wish to ensure the installation is safe. If you suspect there is a fault or risk of failure, you must take steps to inspect the affected circuits urgently.

The Inspection and Test Service
Following a visual appraisal and verification of the entire electrical installation, the following test procedures are applied where appropriate, in order to ascertain the safety of electrical installation :

• Continuity - to ascertain that the earthing is continuous throughout the circuit.
• Bonding Conductors Continuity - to ensure bonding is in place and effective.
• Ring Circuit Continuity - ascertains whether or not the ring is complete.
• Insulation Resistance - to test whether there has been any breakdown in insulation to the installation.
• Polarity - to check that the installation is correctly wired.
• Earth Fault Loop Impedance - to ascertain the Zs of the installation.
• Earth Electrode Resistance - applies to TT systems only, to test the earthing rods.
• RCD testing - to check that Residual Current Device disconnects the supply in the event of a fault.
• Functional testing of isolators and breakers - to ensure that they disconnect the supply.

Upon completion of the electrical testing, a detailed Periodic Inspection Report is supplied containing the following certification:

• Guidance Notes for recipients.
• Schedule of Inspection and Schedule of Test Results.

The engineer who carried out your testing will also talk through the results with you and explain if any remedial work is necessary in order to remedy an unsafe installation. If the electrical installation has any faults, they will be listed under the section of observations and recommendations and will be given one of the following codes:

• C1 - Danger present. Risk of injury. Immediate remedial action required
• C2 – Potentially dangerous. Urgent remedial action required
• C3 – Improvement recommended
• FI – Further investigation required without delay

IEE recommends the maximum time between periodic inspections:

• Commercial premises - max 5 years
• Industrial premises - max 3 years
• Hotels and Public Houses - max 5 years
• Shops and Offices - max 5 years
• Domestic - max 10 years or at change of occupancy
• Residential - max 5 years or at change of occupancy
• Launderettes - max 1 year
• Community Centres/Village Halls - max 5 years
• Churches - max 5 years
• Educational premises - max 5 years
• Places of public entertainment and theatres - max 3 years
• Leisure complexes (excluding swimming pools) - max 3 years
• Swimming Pools - max 1 year
• Construction site/temporary installations - every 3 months