UNIT REVISION

City & Guilds 8202 Unit 303: Electrical design and installation practices and procedures — Complete Revision Guide

A structured revision walkthrough of every topic in City & Guilds 8202 Unit 303 (Electrical 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 T Level students taking the electrical installation specialism.

Free for 7 days · No charge until day 8 · Cancel anytime · Used by 1,000+ UK electricians

8 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.

ShareXinW
Follow

1,000+

UK electricians

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer — DP Electrical

Key Takeaways

  • 1City & Guilds 8202 Unit 303 — Electrical design and installation practices and procedures — is a core component of the T Level in Building Services Engineering — Electrical Installation.
  • 2This unit is typically delivered to T Level students taking the electrical installation specialism and covers 5 main topic areas.
  • 3Across the 5 topics there are 19 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 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.

  • Learners will explain the characteristics and applications of earthing arrangements including:.
  • Learners will explain the characteristics and applications of supply systems including:.
  • Learners will specify the arrangements for electrical installations and systems with regard to provision including:.
Free download

Get the BS 7671 A4:2026 Cheat Sheet — free

Every key change in the 2026 amendment on one page. AFDDs, TN-C-S protection, new schedule columns, model forms. Pinned on your van dash.

  • Every regulation change summarised
  • New model forms (EIC + MEIWC)
  • Free PDF — no subscription

We'll email it once. No spam — unsubscribe any time.

02 · Unit Revision

Topic 2: 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.

  • Learners will explain the purpose of earthing and protective conductors. Learners will also explain the earth fault loop path and earth fault loop impedance and specify requirements and applications of functional earthing..
  • Learners will identify extraneous and exposed conductive parts and select suitably sized protective conductors in accordance with BS 7671..
  • Learners will describe the requirements and measures for protection against electric shock. Learners will also state the maximum disconnection time for different types of circuit..
03 · Unit Revision

Topic 3: Protection against overcurrent

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.

  • Learners will identify types of and reasons for overcurrent including:.
  • Learners will explain the operating principles, applications and limitations of protective devices including:.
  • Learners will identify fault current capacities of devices including:.
04 · Unit Revision

Topic 4: 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.

  • Learners will describe the characteristics of standard electrical circuits including:.
  • Learners will outline the key characteristics of particular electrical systems and circuits and the applications of these circuits and systems including:.

Practise with unlimited mock exams

AI-generated mocks, instant marking, and explanations on every question — targeted at your weakest topics. From £6.99/mo.

Start practising free
Download on the App StoreGet it on Google Play
05 · Unit Revision

Topic 5: The electrical design procedure Level 3 Advanced Technical Diploma in Electrical Installation (450) (8202-30)

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.

  • Learners will state the purpose of diversity factors and determine the maximum demand (of an installation) after the application of diversity..
  • Learners will determine appropriate design current for single-phase and three-phase circuits..
  • Learners will select suitably ratings of protective devices..
  • Learners will establish the installation method reference..
  • Learners will determine appropriate rating factors from BS 7671..
  • Learners will determine the minimum cross-sectional area of live conductors taking into consideration current carrying capacity and voltage drop..
  • Learners will establish if voltage drop is acceptable..
  • Learners will verify if the disconnection times have been achieved and evaluate thermal constraints. Guidance for delivery It is important that the learners have a full understanding of the underpinning knowledge of each of the topics. The practical application of this knowledge and understanding in the working environment is very important. Learners must be able to apply their knowledge and understanding to a wide range of situations covering working safely with different types of equipment and in different working environments. Although some of the content may be delivered in a classroom environment, it is important that learners can relate this knowledge and understanding to actual workshop situations, practical tasks and applications. It is expected that a range of delivery methods will be used including presentations, internet research and, where applicable, visiting speakers. Level 3 Advanced Technical Diploma in Electrical Installation (450) (8202-30).
06 · 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 City & Guilds 8202 Unit 303 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 City & Guilds 8202 Unit 303 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.

Frequently Asked Questions

What electricians say

Verified reviews from the UK App Store.

One App for Everything!

Elec-Mate is my go to app for business and electrical work. It's feature rich without feeling cluttered. A true all in one app for quotes, certs, calculations, RAMS, EICRs, and more. I use it every day without fail, and it makes my workflow much smoother since I'm not jumping between apps anymore. The price-to-feature ratio is excellent. Any issues I've had, the developer responds within the hour and usually fixes them the same day. 100% recommend.

Apple App Store · GBR

Fantastic app for electricians

I've used the app and the web based version for a while now and it's well worth the investment. If you're an apprentice or experienced Spark give it a go, you won't be disappointed.

Apple App Store · GBR

Absolutely amazing

I've been using Elec-Mate for a while now, and honestly, it's one of the best apps I've ever downloaded. Every aspect of it feels thoughtfully designed, from the clean and intuitive interface to the powerful features that make everything so easy to manage. It's clear that a lot of care and attention went into building this app, and it shows in every detail.

Apple App Store · GBR

Trusted by electricians across the UK

Real feedback from real sparks

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer

Sole Trader · DP Electrical

“I've won two contracts this month because I could turn quotes around same-day with the AI cost engineer.”

Nathan Perry

Electrician · NP Electrical Services

“The study centre got me through my AM2. Mock exams and flashcards are brilliant.”

Jake Pizey

3rd Year Apprentice · Apprentice

7-Day Free Trial — Cancel Anytime, No Hassle

For Apprentices: Pass City & Guilds 8202 Unit 303 with Confidence

Join 1,000+ UK apprentices using Elec-Mate for mock exams, flashcards and revision notes mapped to every unit. 7-day free trial — see your progress on the tutor dashboard.

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer, DP Electrical

From £6.99/mo after trial — less than a coffee a week

or download the app
Download on the App StoreGet it on Google Play
7 days free, then from £6.99/moCancel in one tap — no calls, no hassleiOS, Android & WebBS 7671 compliant
16
Certificate Types
70+
Calculators
46+
Training Courses
8
AI Agents

1,000+ electricians · From £6.99/mo after trial

We use cookies to improve the app and measure what works. Cookie Policy