Inspect and test highway electrical systems, equipment and components — Lantra Awards Vocationally-Related Qualification Construction & Building Services Revision

    This subtopic covers the essential skills and knowledge for inspecting and testing highway electrical systems, with a specific focus on electric vehicle an

    Topic Synopsis

    This subtopic covers the essential skills and knowledge for inspecting and testing highway electrical systems, with a specific focus on electric vehicle and on-street charging installations. It emphasises safe working practices, adherence to regulatory standards, and the accurate recording and interpretation of test results to verify system integrity and compliance.

    Key Concepts & Core Principles

    Exam Tips & Revision Strategies

    Common Misconceptions & Mistakes to Avoid

    Examiner Marking Points

    Inspect and test highway electrical systems, equipment and components

    LANTRA AWARDS
    vocational

    This subtopic covers the essential skills and knowledge for inspecting and testing highway electrical systems, with a specific focus on electric vehicle and on-street charging installations. It emphasises safe working practices, adherence to regulatory standards, and the accurate recording and interpretation of test results to verify system integrity and compliance.

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    Learning Outcomes
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    Assessment Guidance
    3
    Key Skills
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    Key Terms
    4
    Assessment Criteria

    Assessment criteria

    Lantra Awards Level 3 Technical Occupational Entry NVQ in Highway Electrical Systems (Diploma) (Electric Vehicle and On-street Charging)

    Topic Overview

    This qualification focuses on the installation, maintenance, and repair of highway electrical systems, with a specific emphasis on electric vehicle (EV) charging infrastructure and on-street charging points. It covers the technical skills required to work safely and competently on street lighting, traffic signals, and EV charging units, ensuring they meet current regulations and standards. As the UK transitions to electric vehicles, this NVQ is critical for developing a skilled workforce capable of supporting the national charging network.

    The course combines practical on-the-job training with theoretical knowledge, covering topics such as cable laying, jointing, earthing, and testing of electrical systems. It also addresses the unique challenges of on-street charging, including integration with existing street furniture, load management, and compliance with the Electric Vehicle (Smart Charge Points) Regulations 2021. By completing this diploma, students demonstrate their ability to work independently and as part of a team on live highway environments.

    This qualification sits within the broader Construction & Building Services sector, linking to civil engineering, electrical installation, and sustainable transport infrastructure. It prepares students for roles such as Highway Electrical Technician or EV Charge Point Installer, and provides a pathway to further study or supervisory positions. Mastery of these skills is essential for meeting the UK's net-zero targets and ensuring public safety on roads.

    Key Concepts

    Core ideas you must understand for this topic

    • →Cable identification and routing: Understanding different cable types (e.g., SWA, PVC) and their correct installation depths and separation distances from other services.
    • →Earthing and bonding: Properly connecting systems to earth to prevent electric shock, including TN-S and TN-C-S systems, and bonding of metallic street furniture.
    • →Load management for EV charging: Balancing power demand across multiple charge points to avoid overloading the local distribution network, using techniques like dynamic load balancing.
    • →Regulatory compliance: Adhering to BS 7671 (IET Wiring Regulations), the Electric Vehicle (Smart Charge Points) Regulations, and the Traffic Signs Manual for installation safety and functionality.
    • →Testing and commissioning: Performing insulation resistance tests, earth fault loop impedance tests, and functional tests on charging units and lighting columns to verify safety and performance.

    Learning Objectives

    What you need to know and understand

    • Demonstrate safe isolation and lockout/tagout procedures prior to commencing electrical inspection and testing.
    • Select and verify the correct test instruments for measuring insulation resistance, earth fault loop impedance, and RCD operation on highway electrical systems.
    • Perform visual inspections and functional tests on electric vehicle charging points to identify defects, damage, or non-compliance.
    • Analyse test data to validate compliance with BS 7671 and the IET Code of Practice for Electric Vehicle Charging Equipment Installation.
    • Compile comprehensive inspection and test reports, including schedules of results and recommendations for remedial action where necessary.

    Assessment Criteria

    Key criteria assessors look for in your portfolio

    • Award credit for correctly demonstrating the use of a proving unit and voltage indicator to confirm safe isolation.
    • Expect evidence of appropriate test sequences, such as continuity of protective conductors before polarity checks.
    • Check that recorded test values are compared against standardised maximum/minimum limits and deviations are clearly noted.
    • Assess the candidate’s ability to identify and label non-conformities, and to suggest practical corrective measures.

    Assessment Guidance

    Guidance for achieving higher grades

    • 💡Always reference the latest edition of the IET Wiring Regulations and the Code of Practice for EV Charging Equipment; be explicit about which version you are applying.
    • 💡During practical assessment, talk through each step of your testing procedure to demonstrate your understanding of the rationale behind each action.
    • 💡Double-check all documentation for legibility and completeness; missing contractor details or test instrument serial numbers can cause a referral.
    • 💡Always reference the latest edition of BS 7671 and any amendments (e.g., Amendment 2 for EV charging). Examiners look for up-to-date knowledge, especially regarding Section 722 for electric vehicle charging installations.
    • 💡When answering questions on installation methods, include specific cable depths (e.g., 450mm for road crossings, 600mm under carriageways) and separation distances from other services (e.g., 100mm from gas pipes). This shows practical understanding.
    • 💡For fault-finding scenarios, use a systematic approach: visual inspection, then testing (insulation resistance, continuity, earth fault loop impedance), and finally functional checks. Explain each step and expected readings to demonstrate competence.

    Common Mistakes

    Common errors to avoid in your coursework

    • Omitting the verification of test instruments (using a proving unit) before and after testing, leading to potentially unsafe practices.
    • Misinterpretation of insulation resistance results due to not considering environmental factors like moisture ingress in charging equipment enclosures.
    • Failing to carry out the specific RCD tests required for EV charging systems, such as DC leakage or Type A/Type B sensitivity checks.
    • Misconception: EV charge points can be installed like any other electrical socket. Correction: They require specific considerations for load management, communication protocols (e.g., OCPP), and compliance with smart charging regulations to avoid grid overload.
    • Misconception: Street lighting and EV charging can share the same circuit without isolation. Correction: They must be on separate circuits with appropriate protection, as EV charging draws higher currents and requires RCD protection (Type A or B) to prevent nuisance tripping.
    • Misconception: Earthing for highway electrical systems is the same as domestic installations. Correction: Highway systems often use TT earthing due to lack of a metallic supply cable sheath, requiring additional earth electrodes and regular testing to ensure low resistance.

    Frequently Asked Questions

    Common questions students ask about this topic

    Before You Start

    Prior knowledge that will help with this topic

    • •Basic electrical principles: Understanding of voltage, current, resistance, and power, as well as AC/DC theory and single-phase vs three-phase supplies.
    • •Health and safety awareness: Knowledge of risk assessment, method statements, and safe working practices in highway environments, including traffic management and personal protective equipment (PPE).
    • •CSCS card or equivalent: A valid Construction Skills Certification Scheme (CSCS) card for highway electrical work is typically required before starting the NVQ.

    Key Terminology

    Essential terms to know

    • Safe isolation and live testing procedures
    • Testing methodologies for EV charging equipment
    • Regulatory compliance (BS 7671, IET Codes)
    • Instrument selection, calibration and verification
    • Recording and reporting test outcomes

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