---
title: "Fundamental requirements of electrical wiring"
subject: "Building Technology"
chapter: 12
key: "semester_6/building_technology:electrical-wiring-requirements"
source: https://www.bctengineer.com/q/semester_6/building_technology/electrical-wiring-requirements
site: BCT Engineering
---

# Fundamental requirements of electrical wiring

Building Technology · Chapter 12: Other services in building

- Asked in: 2075 Baisakh, 3 marks
- Video: [5 tips for Rough-in Phase on New Construction. Electrical wiring.](https://www.youtube.com/watch?v=dgmwJWLs084) — Electrical Code Coach
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/electrical-wiring-requirements
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-12

## Question

Describe the fundamental requirements of electrical wiring.

## Short answer

Wiring must ensure safety via insulation, earthing, and protective devices; provide adequate capacity with low voltage drop; be durable, economical, accessible for maintenance, neat, flexible for extensions, and reliable with separate circuits; all must comply with standards.

## Answer

The fundamental requirements of good electrical wiring are:
1. **Safety:** of persons and property - well-insulated conductors, protection by fuse/MCB/ELCB, and proper earthing.
2. **Adequate capacity:** conductor size sufficient for the load current, with a margin for future increase; voltage drop kept within 3-5%.
3. **Durability:** quality material that resists moisture, heat and mechanical damage, for long life.
4. **Economy:** cost-effective in material and labour, with short runs.
5. **Accessibility:** switches, boards and joints within reach for operation and repair.
6. **Appearance:** neat and concealed where possible, so it does not spoil the interior.
7. **Flexibility and extension:** easy to add points later.
8. **Reliability:** separate circuits, so that a fault does not cut the whole supply.
9. **Compliance** with the electricity rules and standards (IS 732, NBC 207).

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which provisions ensure safety in electrical wiring?
   A. Bare conductors for cooling
   B. Well-insulated conductors, protection by fuse/MCB/ELCB and proper earthing
   C. Thin wires to save cost
   D. Hidden joints without boxes
   Answer: B. Safety to persons and property needs good insulation, protective devices and earthing. (Key point: Safety)

2. What does adequate capacity require?
   A. Conductor sized for the load current with margin for future increase, voltage drop within 3-5%
   B. The smallest conductor possible
   C. Voltage drop of 20%
   D. Conductor sized for present load with no margin
   Answer: A. Conductors must carry the load with a margin for growth and keep voltage drop within 3-5%. (Key point: Adequate capacity)

3. How does wiring achieve reliability?
   A. By putting all points on one circuit
   B. By removing fuses
   C. By using separate circuits so a fault does not stop the whole supply
   D. By running wires in the longest path
   Answer: C. Separate circuits isolate a fault so the rest of the building keeps its supply. (Key point: Reliability)

4. What does the requirement of accessibility mean?
   A. Switches, boards and joints can be reached for operation and repair
   B. Wires should be buried beyond reach
   C. Switch boards should be above ceilings
   D. Joints should be sealed in plaster
   Answer: A. Accessible switches, boards and joints allow easy operation, inspection and repair. (Key point: Accessibility)

## Related in Building Technology

- [Electrical wiring systems](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aelectrical-wiring-systems) — Building Technology, chapter 12, asked 3×
- [Electrical services principles, wiring, safety](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aelectrical-principles-wiring-safety) — Building Technology, chapter 12
- [Safety precautions in electrical works](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aelectrical-safety) — Building Technology, chapter 12, asked 3×

## Related in other subjects

- [General electrical rules for installation and wiring](https://www.bctengineer.com/question.md?key=semester_6%2Findustrial_power_distribution_and_illumination%3Aelectrical-rules-installation) — Industrial Power Distribution and Illumination, chapter 1, asked 3×
- [Electrical and mechanical requirements of insulators](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Ainsulator-requirements) — Power System Analysis I, chapter 2
- [Types of household wiring](https://www.bctengineer.com/question.md?key=semester_1%2Fbasic_electrical_and_electronics_engineering%3Atypes-of-household-wiring) — Basic Electrical and Electronics Engineering, chapter 4, asked 2×
- [High conducting materials: requirements and classification](https://www.bctengineer.com/question.md?key=semester_5%2Felectric_machine_design%3Ahigh-conducting-materials) — Electric Machine Design, chapter 1, asked 3×