The difference between initial verification and periodic inspection and testing
Unlike initial verification, it is common practice when performing periodic inspection and testing to use sampling rather than attempting to inspect and test the complete electrical installation. Limitations is the name given to the limits imposed on the inspection and testing activity by practical considerations. The 'extent and limitations' can be used to tailor the inspection and testing process to cover anything from the complete installation to maybe just one circuit or even one piece of equipment. Observations generally cover two categories of deficiency: defects and non-compliances. A defect refers to a part of the installation that is 'defective', that is has become damaged or worn to a point where it affects the continuing safety of the electrical installation. A non-compliance, however, refers to a part of the installation that fails to comply with the latest edition of the IET Wiring Regulations.