Electrical testing is essential for both new and existing electrical installations. All electrical wiring and equipment will deteriorate with age and every electrical installation will require testing and inspecting at various stages throughout its life to ensure the system is safe for continued use. Even new installations should be thoroughly tested and inspected before being put into service to ensure that they meet the current standards of the IEE wiring regulations and have not been compromised by human error or damage during construction work.
The IEE electrical testing regulations can be found in BS7671, Chapter 61 which includes details of tests which should be carried out to determine whether a wiring system is acceptable for use. Section 611 of this deals with new installations and gives a list of inspections that should be carried out before testing.
Determining the condition of an existing electrical installation, the frequency of periodic testing and the recording of test results are also an important part of an inspection and testing agenda. These are covered in Chapters 62 and 63 of the regulations and give the requirements for detailed examination, verification and certification. Model forms for recording test results and inspections can be found in Appendix 6.
Electrical testing involves an element of risk and the IEE Regulations include the requirements for Health and Safety regarding Competent Persons and Safe Isolation. Anyone carrying out inspection and testing has a duty to ensure the safety of themselves and others.
The definition of a Competent Person can be found in Part 2 of BS7671 and would be reasonably need to meet all of the following requirements:
- Possess enough experience and technical knowledge to avoid danger to themselves and others by following Safe Isolation and Testing Procedures
- Be skilled and familiar with the testing procedures and safe operation of appropriate test instruments
- Have a knowledge of the current requirements of BS7671 relevant to the type of installation for inspection and testing
- Be in possession of enough information about the installation to enable them to carry out the work safely. This would include being able to re-instate the installation in a completely safe and serviceable state after the inspection and testing is completed.
Testing and inspecting of electrical circuits will require normally ‘live parts’ to be exposed by the inspector. Regulation 611 requires that testing and inspection procedures should be undertaken with the relevant circuits disconnected from the supply. Any work must be carried out with regard to compliance with the Electricity at Work Regulations which refers to the dangers of any work or activity near ‘live’ conductors.
Many inspections will involve the removal of accessory covers. Where access to normally ‘live parts’ is required it is important that safe isolation procedures are followed as recommended in the Electrical Safety Council’s Best Practice Guide 2.