---
title: "Define secondary distribution"
subject: "Transmission and Distribution System Design"
chapter: 5
key: "semester_8/transmission_and_distribution_system_design:define-secondary-distribution"
source: https://www.bctengineer.com/q/semester_8/transmission_and_distribution_system_design/define-secondary-distribution
site: BCT Engineering
---

# Define secondary distribution

Transmission and Distribution System Design · Chapter 5: Electric Power Distribution

- Asked in: 2080 Chaitra, 1 marks
- Video: [Types of Distribution System | Primary and Secondary Distribution.](https://www.youtube.com/watch?v=7v1IkvTOvrQ) — Kirankumar
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_8/transmission_and_distribution_system_design/define-secondary-distribution
- Whole chapter: https://www.bctengineer.com/md/semester_8/transmission_and_distribution_system_design/chapter-5

## Question

With respect to a distribution system, define secondary distribution.

## Short answer

Secondary distribution is the part of the system operating at utilization voltage (400 V three-phase/230 V single-phase in Nepal), carrying power from distribution transformers via LT lines to consumers. It is typically radial and includes overhead LT lines, ABC or cables.

## Answer

**Secondary distribution** is the part of the distribution system that operates at the **utilization voltage**: 400 V three-phase (four-wire) or 230 V single-phase in Nepal. It carries power from the distribution transformer through LT lines and service mains to the consumers' premises.

It is mostly overhead LT lines, ABC or cables, run radially from each transformer.

## Check yourself

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

1. At what voltage does secondary distribution operate in Nepal?
   A. 400 V three-phase or 230 V single-phase
   B. 11 kV
   C. 33 kV
   D. 132 kV
   Answer: A. It operates at utilisation voltage. (Key point: Voltage level)

2. What does it carry?
   A. Power from the grid substation to transformers
   B. Power from the transformer through LT lines and service mains to consumers
   C. Power from generators
   D. Power between substations
   Answer: B. It ends at the consumer's premises. (Key point: Extent)

3. How is it mostly run?
   A. Meshed
   B. Underground only
   C. Radially from each transformer
   D. At 11 kV
   Answer: C. It is mostly overhead LT, ABC or cable, radial. (Key point: Layout)

## Related in Transmission and Distribution System Design

- [Radial vs loop distribution system](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Aradial-vs-loop-distribution) — Transmission and Distribution System Design, chapter 5, asked 2×
- [T/F: lightning overvoltage in distribution system](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Atf-lightning-distribution-vs-transmission) — Transmission and Distribution System Design, chapter 3
- [Distribution system used in INPS](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Ainps-distribution-system-type) — Transmission and Distribution System Design, chapter 5
- [Monthly energy loss in four secondary lines](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Amonthly-loss-four-secondary-lines) — Transmission and Distribution System Design, chapter 7
- [T/F: radial operation of distribution in Nepal](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Atf-nepal-radial-distribution) — Transmission and Distribution System Design, chapter 5
- [Define distribution transformer](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Adefine-distribution-transformer) — Transmission and Distribution System Design, chapter 5

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