City & Guilds 2391-51 study guide
City & Guilds 2391-51 · Work through your exam, one topic at a time.
City & Guilds 2391-51 is the Level 3 Award in Periodic Inspection, Testing and Certification of Electrical Installations. It is a competence-style qualification for practising electricians who already install and maintain circuits and now need to inspect, test, certify and condition-report existing installations rather than newly commissioned ones. The City & Guilds 2391-51 study guide has 8 sections and about 2,454 words.
01Statutory and non-statutory regulations, standards and guidance
Inspection and testing sits inside a legal framework, and questions test whether you can separate law from standard from guidance. The Health and Safety at Work etc.
298 words, about 1 min02Safe isolation, safety management and safe working practices
Safe isolation is a sequence, not a single action, and the sequence is examined closely. Identify every source of supply to the part to be worked on - parallel supplies, a second consumer unit, PV inverters, generators, UPS, emergency lighting, control circuits and shared or borrowed neutrals.
302 words, about 2 min03Preparation for periodic inspection: documentation, extent, sampling and limitations
The period before the inspection determines whether the report is defensible. Gather previous certificates and reports (EIC, EICR, minor works certificates, schedules of test results), distribution board charts, drawings and as-fitted layouts, design data, maintenance records including alterations and repairs, and details of how the installation is used and why the inspection has been requested.
296 words, about 1 min04Visual inspection and identifying non-compliance and deterioration
Visual inspection is the highest-yield part of a periodic inspection: most defects found in service are visible. Inspect with the installation isolated and safe, working systematically from origin to final circuit.
289 words, about 1 min05Initial verification versus periodic inspection and agreeing scope
Initial verification and periodic inspection answer different questions. Initial verification asks: does this new work comply with the design and with BS 7671?
307 words, about 2 min06Dead testing: continuity, ring final circuits, polarity and insulation resistance
Dead tests are carried out with the supply isolated, in a set order, because later tests depend on earlier ones. Continuity of protective conductors.
306 words, about 2 min07Live testing: earth fault loop impedance, prospective fault current, RCD and functional testing
Live tests confirm that protective devices will operate within the required disconnection time and that residual current devices work. Earth fault loop impedance.
327 words, about 2 min08Recording results, condition reporting, classification codes and recommendations
The output of a periodic inspection is the Electrical Installation Condition Report. Its sections are: details of the client and installation, the date of the previous inspection, the extent and limitations, a summary of condition, observations with classification codes, the schedule of items inspected, the schedule of test results, a recommendation for the next inspection interval, and the declaration and signature.
329 words, about 2 min