Electrical installations in electronics engineering require precise documentation to ensure safety, functionality, and compliance with standards. Working drawings are critical tools that provide detailed visual instructions for executing electrical designs accurately on site. This chapter explores the concept of working drawings, focusing on their role in the electronics engineering field within Kenya, where adherence to standards such as KEBS and ISO is essential for quality and safety.
2.1 Meaning of Working Drawings
Working drawings are specialized technical drawings that present detailed information necessary for the construction, installation, and maintenance of electrical systems. In Kenyan electronics engineering projects, these drawings serve as the primary communication medium between designers, electricians, and project managers, ensuring that installations meet design intent and regulatory requirements.
2.1.1 Definition and Core Characteristics of Working Drawings
Working drawings are comprehensive graphical representations that specify dimensions, materials, layouts, and installation details for electrical components and systems. They differ from conceptual or schematic drawings by providing exact measurements and instructions required for on-site implementation.
- Precision and Detail: Working drawings include exact dimensions, tolerances, and specifications that guide the installation process without ambiguity.
- Standardized Symbols: They utilize internationally recognized symbols, adhering to BS 3939 and IEC standards, ensuring uniform interpretation by all stakeholders.
- Multiple Views: To fully describe complex installations, working drawings incorporate plan views, elevations, and sectional views.
- Annotations and Notes: Detailed notes explain installation procedures, materials, and safety precautions relevant to electronics systems.
- Revision Control: Each drawing includes revision history to track changes, ensuring that the latest version is used on site.
2.1.2 Importance of Working Drawings in Electronics Installation
- Ensures Compliance: They guarantee installations conform to Kenya’s Electrical Installation Regulations and KEBS standards.
- Facilitates Accurate Procurement: Detailed specifications help procurement teams acquire correct materials, avoiding delays and cost overruns.
- Improves Safety: By detailing protective devices and wiring routes, working drawings reduce risks of electrical hazards.
- Streamlines Installation: Clear instructions minimize errors during assembly and commissioning of electronic systems.
- Enables Maintenance and Upgrades: Well-documented drawings support troubleshooting and future expansion of electrical installations.
2.1.3 Types of Working Drawings Commonly Used in Electronics Engineering
Different types of working drawings serve distinct purposes within electrical installation projects, each providing unique details essential for various phases of work.
- Layout Drawings: Show the physical arrangement of electrical equipment, wiring routes, and distribution boards within a facility.
- Wiring Diagrams: Detail the interconnections between electrical components, illustrating cable runs and terminal connections.
- Single Line Diagrams: Simplify complex three-phase systems into a single line representation, indicating power flow and protective devices.
- Panel Schedules: List circuit breakers and loads connected to distribution panels, specifying ratings and settings.
- Installation Details: Focus on specific components such as conduit bends, fixing methods, and earthing arrangements.
2.1.4 Standards and Conventions Governing Working Drawings in Kenya
Adherence to national and international standards ensures that working drawings are universally understood and legally compliant within Kenya’s electronics engineering sector.
- BS 3939 / IEC 60617: Governs graphical symbols for electrical diagrams, ensuring consistency.
- KEBS KS 04-103: Provides guidelines for electrical installations in Kenya, including drawing conventions.
- ISO 128: Specifies general principles of presentation in technical drawings.
- Kenyan Electrical Installation Regulations (2012): Mandate compliance with safe installation practices supported by accurate documentation.
- Drawing Format and Title Blocks: Should follow ISO 7200, including project details-scale, drawing number, and approval signatures.
Practice Questions
- Define working drawings and explain their core characteristics in the context of electronics engineering installations. (10 marks)
- List and describe five reasons why working drawings are important for electrical installations in Kenyan hospitals. (10 marks)
- Identify and explain four types of working drawings used in electronics engineering projects. (12 marks)
- Outline five key standards or conventions that must be observed when preparing working drawings for electrical installations in Kenya. (8 marks)
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Create a free account 🔒2.2 Types of Working Drawings
In the context of Electronics Engineering in Kenya, working drawings serve as the fundamental communication tool between design engineers, installation technicians, and maintenance teams. They provide precise visual instructions required to construct, install,…
🔒2.3 Identification and care of drawing instruments and equipment
In the practice of electronics engineering in Kenya, preparing precise working drawings is fundamental to the success of electrical installations. The quality and accuracy of these drawings depend heavily on the proper use and maintenance of drawing instrument…
🔒2.4 Identification of Drawing Paper Sizes
In the field of electronics engineering, especially in electrical installation projects, the clarity and standardisation of working drawings are paramount. Identifying the correct drawing paper size ensures that the drawings are legible, scalable, and compatib…
🔒2.5 Drawing various types of lines
In Electrical Installation II, mastering the use of different types of lines in technical drawings is essential for clear communication of electrical systems. For electronics engineering professionals in Kenya, precise line usage ensures that electrical layout…
🔒2.6 Drawing title block
In the preparation of working drawings for electrical installations in electronics engineering, the drawing title block is a critical element that ensures clarity, traceability, and professionalism. For electronics engineers in Kenya, especially those working…
🔒2.7 Drawing standard electrical symbols
In the field of electronics engineering in Kenya, preparing accurate and standardized electrical drawings is crucial for effective communication among engineers, technicians, and stakeholders. Standard electrical symbols provide a universal language that simpl…
🔒2.8 Conversion of scales
In Electronics Engineering projects, precise working drawings are essential for accurate installation and maintenance of electrical systems. Often, the actual size of components or layouts cannot be represented on paper at full scale due to space constraints.…
Chapter Summary
Working drawings are detailed plans used to guide the installation of electrical systems, providing precise information necessary for construction and maintenance. Various types of working drawings include layout plans, wiring diagrams, and schematic diagrams, each serving a specific purpose in the electrical installation process. Proper identification and careful handling of drawing instruments and equipment are essential to produce accurate and clear drawings. Understanding the standard sizes of drawing paper ensures that plans are presented in a consistent and professional format. Different types of lines, such as continuous, dashed, and center lines, are drawn according to established conventions to convey specific information on the drawings. The drawing title block contains crucial details like project name, date-scale, and drafter’s information, ensuring proper documentation and traceability. Standard electrical symbols are used universally in working drawings to represent components clearly and avoid confusion. Finally, the ability to convert scales accurately allows the representation of large installations on manageable drawing sizes without losing detail or clarity.
Self-Assessment
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A. Written Assessment
- What is the primary purpose of working drawings in electrical installation projects? (2 marks)
- Identify three types of working drawings commonly used in electronics engineering. (3 marks)
🔒20 more in this section.
Chapter Examination Questions
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SECTION A (40 Marks) - Answer ALL Questions
- Explain the purpose of working drawings in the design and installation of electronic control panels at a manufacturing firm such as ARM Cement Ltd. (4 marks)
- Identify and describe four types of working drawings commonly used in electrical installations for a hospital setting. (4 marks)
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Chapter Practical Activities
Practical 1: Explain and Classify Working Drawings in Electrical Installation
Electronics Engineering · Level 6
Electrical Installation II
PRACTICAL ASSESSMENT
TIME: 3 HOURS
⬇ PDFCandidate Instructions (Candidate Tool)
Type: Individual
INSTRUCTIONS TO CANDIDATE:
1. You are required to perform the following task:
i. Verbally explain the meaning and classification of working drawings with at least three examples for each type.
2. You have been provided with the following resources for the practical task:
| Tools & Equipment | Materials |
|---|
| Pen and pencil | Personal Protective Equipment (PPE) - Dustcoat/Overall |
| Ruler 30cm | A4 size printing papers |
⬇ PDFResources Required (Cutting List)
| S/N | Item | Quantity |
|---|
| 1 | Personal Protective Equipment (PPE) - Dustcoat/Overall | 1 set per Candidate |
| 2 | A4 size printing papers | 5 sheets per Candidate |
| 3 | Pen and pencil | 1 set per Candidate |
| 4 | Ruler 30cm | 1 per Candidate |
⬇ PDFAssessor Guide
| Items to be Evaluated | Marks Available | Marks Obtained | Comments |
|---|
| TASK 1: Explanation of Working Drawings |
Wore Personal Protective Equipment (Dustcoat/Overall)
(Award 1 mark for wearing PPE, 0 if not) | 1 | | |
Applied good housekeeping practice by ensuring a clean and organized working area before starting
(Award 1 mark for good housekeeping) | 1 | | |
Clearly explained the meaning of working drawings
(Award up to 3 marks for clear, accurate explanation) | 3 | | |
Correctly classified working drawings into types (e.g., layout, schematic, wiring, connection drawings)
(Award 1 mark for each correctly named type, max 4) | 4 | | |
Provided at least three examples for each type of working drawing
(Award 1 mark per example, max 5) | 5 | | |
Used appropriate terminology in explanations
(Award up to 2 marks for correct technical terms) | 2 | | |
| Sub-Total | 16 | | |
| PRODUCT CHECKLIST |
Verbal explanation is coherent, complete, and covers meaning, classification, and examples of working drawings
(Award 4 marks for completeness and clarity of verbal explanation) | 4 | | |
| Sub-Total | 4 | | |
| GRAND TOTAL | 20 | | |
ASSESSMENT OUTCOME: ☐ Competent ☐ Not Yet Competent (competent if at least 50%)
Practical 2: Identify and Care for Drawing Instruments
Electronics Engineering · Level 6
Electrical Installation II
PRACTICAL ASSESSMENT
TIME: 3 HOURS
⬇ PDFCandidate Instructions (Candidate Tool)
Type: Individual
INSTRUCTIONS TO CANDIDATE:
1. You are required to perform the following task:
i. Identify and demonstrate proper care for a set of drawing instruments including T-square, set squares, compass, and pencils.
2. You have been provided with the following resources for the practical task:
| Tools & Equipment | Materials |
|---|
| Drawing board | Dustcoat/Overall |
| T-square | |
| Set squares (45° and 30°/60°) | |
| Drawing pencils (2H, HB, 2B) | |
| Compass | |
| Eraser | |
| Sharpener | |
| Protractor | |
| Divider | |
| Drawing pins | |
| Cleaning cloth | |
⬇ PDFResources Required (Cutting List)
| S/N | Item | Quantity |
|---|
| 1 | Drawing board | 1 Pc per Candidate |
| 2 | T-square | 1 Pc per Candidate |
| 3 | Set squares (45° and 30°/60°) | 2 Pcs per Candidate |
| 4 | Drawing pencils (2H, HB, 2B) | 3 Pcs per Candidate |
| 5 | Compass | 1 Pc per Candidate |
| 6 | Eraser | 1 Pc per Candidate |
| 7 | Sharpener | 1 Pc per Candidate |
| 8 | Protractor | 1 Pc per Candidate |
| 9 | Divider | 1 Pc per Candidate |
| 10 | Drawing pins | 5 Pcs per Candidate |
| 11 | Dustcoat/Overall | 1 Pc per Candidate |
| 12 | Cleaning cloth | 1 Pc per Candidate |
⬇ PDFAssessor Guide
| Items to be Evaluated | Marks Available | Marks Obtained | Comments |
|---|
| TASK 1: Identification and Care of Drawing Instruments |
Wore Personal Protective Equipment (Dustcoat/Overall)
(Award 1 mark for PPE worn before handling instruments) | 1 | | |
Identified each drawing instrument correctly by name and function
(Award 1 mark for each correctly identified instrument up to 4 marks) | 4 | | |
Handled drawing instruments carefully to avoid damage
(Award 2 marks for proper handling without dropping or misuse) | 2 | | |
Demonstrated correct cleaning procedure for drawing instruments using cleaning cloth
(Award 2 marks for correct cleaning technique) | 2 | | |
Demonstrated proper storage of drawing instruments after use
(Award 2 marks for correct storage ensuring instruments are safe and secure) | 2 | | |
Applied good housekeeping practice: ensured clean and organized working area before and after task
(Award 1 mark for neat and clean working area) | 1 | | |
Used correct tools for the correct purpose during identification and care
(Award 2 marks for appropriate tool use without misuse) | 2 | | |
Followed safety procedures while handling sharp instruments like compass and sharpener
(Award 2 marks for safe handling practices) | 2 | | |
Answered questions on maintenance schedule for drawing instruments
(Award 2 marks for correct explanation of maintenance frequency and procedures) | 2 | | |
| Sub-Total | 18 | | |
| PRODUCT CHECKLIST |
All drawing instruments identified correctly and labelled
(Award 4 marks if all instruments are correctly identified and labelled) | 4 | | |
Drawing instruments cleaned properly without damage or residue
(Award 3 marks for visibly clean and well-maintained instruments) | 3 | | |
Drawing instruments stored properly in their designated places
(Award 3 marks for neat and safe storage) | 3 | | |
Working area left clean and organized after task completion
(Award 2 marks for good housekeeping after task) | 2 | | |
Demonstrated correct use of instruments based on the provided working drawing
(Award 4 marks for correct demonstration of instrument use as per drawing requirements) | 4 | | |
| Sub-Total | 16 | | |
| GRAND TOTAL | 34 | | |
ASSESSMENT OUTCOME: ☐ Competent ☐ Not Yet Competent (competent if at least 50%)
🔒Identify and label standard drawing paper sizes for electrical installation drawingsPractical 3
🔒Draw Various Types of Lines for Electrical Installation Working DrawingPractical 4
🔒Draw a Complete Title Block on an A3 Drawing SheetPractical 5
🔒Draw standard electrical symbols to scale for installation working drawingsPractical 6
🔒Scale conversion of an electrical layout drawingPractical 7
🔒Prepare a Simple Electrical Installation Working DrawingPractical 8
🔒Select Appropriate Paper Size for Electrical Installation DrawingPractical 9
🔒Maintain and Store Drawing InstrumentsPractical 10
