City & Guilds 2391 Course: Everything You Need to Know

The City & Guilds 2391-52 is the Level 3 Award in Initial Verification and Periodic Inspection and Testing of Electrical Installations. It is the UK's standard qualification for electricians who want to inspect, test, and certify electrical installations — both new installations (initial verification) and existing ones (periodic inspection and testing).

This qualification is essential for anyone who wants to sign off their own electrical work, carry out EICRs (Electrical Installation Condition Reports), or work as an independent electrician. Without the 2391, you cannot demonstrate the competence needed to inspect and test installations to the standard required by BS 7671 and competent person schemes.

The 2391-52 replaced the older 2391-50 (initial verification only) and 2391-51 (periodic inspection only) as a combined qualification that covers both disciplines. It also supersedes the 2394/2395 qualifications that some electricians may still hold.

The 2391-52 is a comprehensive course that covers both the theory and practice of electrical inspection and testing. You will learn the correct procedures for every test in the BS 7671 testing sequence, how to interpret results, and how to produce compliant certification.

Safe isolation procedures

Before any testing can begin, you must safely isolate the circuit or installation. The course covers the GS38 guidance on safe isolation, the correct use of voltage indicators and proving units, and the lock-off procedures that protect you and others.

Dead testing

• ✓Continuity of protective conductors — verifying earth paths using R1+R2 method
• ✓Continuity of ring final circuits — confirming ring mains are complete and unbroken
• ✓Insulation resistance testing — measuring at 500V DC to confirm minimum 1 megohm
• ✓Polarity checks — ensuring live, neutral, and earth are correctly connected throughout

Live testing

• ✓Earth fault loop impedance (Zs) — measuring the total impedance of the earth fault path
• ✓Prospective fault current (Ipf) — determining maximum fault current at each point
• ✓RCD testing — verifying trip times at rated current, 5x rated current, and ramp tests
• ✓Functional testing — confirming switchgear, controls, and interlocks operate correctly

Certification and reporting

You will learn how to complete the official certification documents: Electrical Installation Certificates (EICs) for new work, Minor Works Certificates for small jobs, and Electrical Installation Condition Reports (EICRs) for periodic inspections. Correct paperwork is as important as correct testing.

The 2391-52 assessment has two components, both of which must be passed to achieve the qualification. The assessment is rigorous because the qualification certifies that you are competent to inspect and test real installations where safety is critical.

Written examination

The written exam tests your theoretical knowledge of inspection and testing. It covers the testing sequence, acceptable values and limits, the requirements of BS 7671 for inspection and testing, and your ability to interpret test results. The exam is open-book — you can refer to BS 7671 and the IET Guidance Note 3.

Practical assessment

The practical assessment is carried out on a real or purpose-built electrical installation under exam conditions. You will be required to carry out a full sequence of tests, record results accurately, identify any defects, and complete the appropriate certification. Time management is critical — you must work methodically and efficiently.

The 2391-52 is not an entry-level qualification. It builds on a foundation of electrical knowledge and practical experience. You need to understand how electrical installations work before you can inspect and test them competently.

Essential prerequisites

• ✓Current 18th Edition Wiring Regulations qualification (C&G 2382-22) — this is mandatory
• ✓Level 2 and/or Level 3 Diploma in Electrical Installation (C&G 2365 or equivalent)
• ✓Practical experience of electrical installation work
• ✓Familiarity with electrical test instruments (multifunction testers, insulation resistance testers)

Recommended experience

While there is no formal experience requirement set by City & Guilds, you will find the course and assessment significantly easier if you have hands-on experience of electrical installation work. Understanding how circuits are wired, how consumer units are configured, and what common faults look like will help you enormously during both the theory and practical components.

The 2391-52 course typically takes 2 to 3 weeks to complete. At Total Skills, we deliver the course through a combination of classroom theory, practical workshops, and guided practice on real installations at our Nottingham training centre.

Typical course structure

• ✓Week 1: Theory — BS 7671 requirements, testing sequence, acceptable values, safe isolation
• ✓Week 2: Practical — hands-on testing on real installations, instrument familiarisation
• ✓Week 3: Assessment preparation, mock exams, written examination, and practical assessment

The exact schedule varies depending on the cohort and intake. Some providers offer compressed courses or evening/weekend options. Check the course page for current availability and dates.

The 2391 is one of the most important qualifications an electrician can hold. It is the gateway to several key career capabilities and is effectively essential for anyone who wants to work independently or run their own electrical business.

What the 2391 enables you to do

• ✓Sign off your own electrical work by issuing Electrical Installation Certificates
• ✓Carry out EICRs (Electrical Installation Condition Reports) for landlords and homeowners
• ✓Join a competent person scheme (NICEIC, NAPIT) — most require the 2391 or equivalent
• ✓Self-certify notifiable work under Part P of the Building Regulations
• ✓Work independently as a self-employed electrician
• ✓Command higher day rates — inspection and testing is premium, skilled work

Without the 2391, you are limited in what you can do as an electrician. You cannot sign off your own work, you cannot carry out EICRs, and you will not be accepted by most competent person schemes. For anyone serious about a career in electrical work, the 2391 is not optional — it is essential.

Once you have passed the 2391, there are several steps you should take to make the most of your new qualification and start building your inspection and testing career.

Immediate next steps

• ✓Join a competent person scheme (NICEIC, NAPIT, or equivalent) to self-certify your work
• ✓Invest in calibrated test equipment — a multifunction tester is essential
• ✓Start offering EICR services to landlords, letting agents, and estate agents
• ✓Practise the full testing sequence on every job to build speed and confidence
• ✓Consider the NVQ Level 3 to complete your pathway to the JIB Gold Card

The 2391 also positions you well for specialist qualifications such as the C&G 2921 EV Charging Equipment Installation, where inspection and testing competence is essential for commissioning chargepoints.