Installations that conform to the standards laid down in BS7671 are regarded by the HSE as likely to achieve conformity with the relevant parts of the Electricity at Work Regulations 1989.
Chapter 62 in the IET Wiring Regulations covers Periodic Inspection and Testing requirements. Regulation 621-01 states that periodic inspection and testing of an electrical installation shall be carried out to determine, so far as is reasonably practicable, whether the installation is in a satisfactory condition for continued service.
Regulation 622-01 stipulates that the scope of the periodic inspection and testing shall be decided by a competent person, taking into account the availability of records and the use, condition and nature of the installation.
Table 3.3 in the IET Inspection and Testing Guidance Note 3, indicates which periodic tests are to be carried out on existing installations. The person carrying out the testing is required to decide which of the tests are appropriate by using their experience and knowledge of the installation being inspected and tested and by consulting any available records.
It is important that any periodic inspection and testing regime put in place meets the standards of the codes of practice but at the same time is a practical operation which can be completed efficiently and with minimum disruption to the business. The ability of the company to clearly demonstrate compliance is a key requirement of any new periodic inspection/testing package.
Periodic inspection and testing is necessary because all electrical installations deteriorate due to a number of factors such as ageing, excessive electrical loading, corrosion and general wear and tear.
A periodic test and inspection may be less onerous than an initial one. Completing unnecessary periodic testing can be dangerous, disruptive and costly. This is often misunderstood by companies wishing to achieve legal compliance.
It is good practice to work to a periodic electrical testing plan, and this will ensure compliance with the Regulations without incurring excessive disruption and costs to the user. Employ a competent person as per Regulation 621-05 to determine the scope of the tests after taking into account the condition and nature of the installation.