UNIT REVISION

EAL Level 3 Unit TE3-04: Design and Installation Practices and Procedures — Complete Revision Guide

A structured revision walkthrough of every topic in EAL Level 3 Unit TE3-04 (Design and Installation Practices and Procedures). Use it as a personal study checklist — work through each topic, tick off the points you can confidently explain or calculate, and use the linked Elec-Mate tools to practice the calculation-led parts. Designed for EAL Level 3 apprentices.

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18 min readUpdated 2026-05-18Andrew Moore, Founder of Elec-Mate

Written and reviewed by Andrew Moore, founder of Elec-Mate, against BS 7671:2018+A4:2026, IET Guidance Note 3 and the IET On-Site Guide.

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Key Takeaways

  • 1EAL Level 3 Unit TE3-04 — Design and Installation Practices and Procedures — is a core component of the EAL Level 3 Electrotechnical Technical Occupational Entry qualification.
  • 2This unit is typically delivered to EAL Level 3 apprentices and covers 8 main topic areas.
  • 3Across the 8 topics there are 45 specific points you should be able to explain, demonstrate or calculate before the end-of-unit assessment.
  • 4Common assessment formats include online multiple-choice exams, written short-answer papers, and practical workshop tasks observed by your tutor.
  • 5Use the structured topic list below as a personal checklist — work through each point and confirm you can explain it without referring to your notes.
  • 6The Elec-Mate apprentice tier includes mock exams, flashcards, and revision notes mapped to this unit. Use the tools to test yourself between college blocks and on-site days.
01 · Unit Revision

Topic 1: The applications of wiring systems

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • Explain the characteristics and requirements of electrical cables including their:.
  • Explain the characteristics and requirements of:.
  • Describe the factors which affect the selection of wiring systems, associated equipment and enclosures.
  • Select suitable wiring systems and equipment appropriate to the situation and use.
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02 · Unit Revision

Topic 2: The practices and procedures for carrying out electrical work

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • State how to select and safely use:.
  • State how to measure and mark out positions for wiring systems and equipment.
  • State the criteria for selecting and safely using fixing devices for wiring systems, associated equipment and enclosures.
  • Specify the installation methods and procedures to ensure the installation meets the specification and statutory and non-statutory regulations.
  • Specify methods and techniques for restoring the building fabric.
  • Describe how to maintain fire and acoustic protection.
03 · Unit Revision

Topic 3: The characteristics and applications of supply systems and consumer's equipment

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • Explain the characteristics and applications of earthing arrangements.
  • Explain the characteristics and applications of supply systems.
  • Specify the arrangements for electrical installations and systems with regard to provision for isolation, switching, protection and control.
04 · Unit Revision

Topic 4: Earthing and protection

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • Explain the purpose of earthing and protective conductors.
  • Identify extraneous and exposed conductive parts.
  • Describe the requirements and measures for protection against electric shock.
  • State the maximum disconnection time for different types of circuit.
  • Explain the earth fault loop path and earth fault loop impedance.
  • Specify requirements and applications of functional earthing..
  • Select suitably sized protective conductors in accordance with BS 7671.
05 · Unit Revision

Topic 5: Protection against electrical faults

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • Identify types of and reasons for overcurrent Cover: Short circuits, earth faults, and overloads, and typical reasons for these occurring..
  • Explain the applications and limitations of protective devices.
  • Identify fault current capacities of devices Cover: Identifying fault current capacities of devices, and why this capacity is important for safety and correct function..
  • Describe the need for selectivity between protective devices.

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06 · Unit Revision

Topic 6: Electrical systems and circuits

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • Describe the characteristics of standard electrical circuits.
  • Outline the key characteristics of particular electrical systems and circuits and the applications of these circuits and systems.
07 · Unit Revision

Topic 7: Install wiring systems and equipment

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • Carry out the appropriate preparations for electrical installation.
  • Select the appropriate tools and equipment for the electrical installation Cover through producing a materials, tools and equipment list..
  • Follow safe working procedures Cover: Adopting PPE, keeping a safe work area. Restoring work area afterwards..
  • Use the appropriate tools safely Cover: Using tools in a safe manner. Returning after use..
  • Install wiring and associated equipment and components accurately to the specification Learners will have to effectively mark up the work area/bay to install wiring systems and equipment. (I.e., marking up form a fixed datum line to facilitate accuracy). They will then proceed to install materials to the specification. Checking work during installation and on completion. Adjusting approach and problem solving as needed..
  • Apply the techniques and methods for the safe and effective termination and connection of cables..
  • Maintain a tidy and safe work area Cover: Disposal of waste in accordance with recycling practice..
08 · Unit Revision

Topic 8: The electrical design procedure

In this section you should be confident with the following points. Each one is a specific topic you should be able to explain, demonstrate, or calculate.

  • State the purpose of diversity factors Cover: Appreciation of factors and how they apply..
  • Verify if the disconnection times have been achieved.
  • Evaluate thermal constraints Cover: Application of the adiabatic formula..
  • Interpret the requirements of sources of information that support electrical installation and design work.
  • Select suitable current using equipment giving consideration to energy efficiency and relevant codes of practice for sustainability.
  • Determine the maximum demand (of an installation) after the application of diversity.
  • Determine the design current Cover: Single and three phase circuits..
  • Select a suitably rated protective device Cover: Application of BS 7671 for a range of typical scenarios..
  • Establish the installation method reference.
  • Determine appropriate rating factors.
  • Determine the minimum cross-sectional area of live conductors taking into consideration current carrying capacity and voltage drop.
  • Establish if the voltage drop is acceptable Cover: Application of BS 7671 for a range of typical scenarios..
09 · Unit Revision

Study This Unit with Elec-Mate

Elec-Mate’s apprentice tier turns this unit checklist into an active study plan. You get mock exam questions, flashcards, and revision notes mapped to this unit, plus working calculators for every calculation-led topic. Most apprentices use the app between college blocks and on the train to site — short bursts of revision compound across the year.

For apprentices

The Elec-Mate apprentice tier includes mock exams, flashcards, and revision notes for EAL Level 3 Unit TE3-04 plus every other unit in your qualification. 7-day free trial — see your progress on the tutor dashboard.

A Five-Step Revision Plan for This Unit

A repeatable approach that works for EAL Level 3 Unit TE3-04 and every other unit in your qualification.

1

Read through every topic point once

Start at Topic 1 and read every bullet point. Don’t try to memorise — just get familiar with the scope. Note any topic that feels unfamiliar so you can come back to it.

2

Map each topic to its calculator or guide

For calculation-led topics, open the relevant Elec-Mate calculator and try one worked example. For theory-led topics, find the matching section in BS 7671 or the IET On-Site Guide.

3

Work through Elec-Mate mock exam questions

The Elec-Mate apprentice tier includes mock questions mapped to this unit. Aim for 80%+ on a clean run before the real exam.

4

Get hands-on time on the bench

For practical units (inspection and testing, installation), ask your tutor for additional workshop access. The bench is where the points click.

5

Self-explain each topic to a peer

If you can explain a topic in your own words to another apprentice and they understand it, you know it. This is the single highest-leverage revision tactic.

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