Testing and commissioning is where the quality of the installation is formally verified. Inadequate planning of this phase is a frequent cause of delayed handovers and contractual disputes. The testing and commissioning programme must be planned from the outset, not treated as an afterthought at the end of the project.
The testing phase requires qualified testers (holding City & Guilds 2391 or equivalent), calibrated test instruments, completed installation work (testing incomplete circuits is pointless), and adequate time in the programme. On larger projects, a dedicated testing team is engaged, and their access must be coordinated so they can test areas in sequence as installation completes.
The testing sequence follows the requirements of BS 7671 Chapter 64: continuity of protective conductors, continuity of ring final circuit conductors, insulation resistance, polarity, earth fault loop impedance, prospective fault current, and RCD operation. Every test result must be recorded on the schedule of test results and any failures investigated and rectified before the circuit can be certified.
Commissioning follows testing and involves energising systems and verifying that they operate as intended. Lighting control systems, fire alarm interfaces, emergency lighting, BMS integration, and metering all require commissioning by competent persons. Commissioning records must demonstrate that each system functions correctly under normal and fault conditions.
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Professional testing and certification tools
Elec-Mate's testing tools produce BS 7671-compliant EICs, EICRs, and minor works certificates with integrated schedule of test results.