Chapter 1 Introduction
Table of Contents
Chapter 1. Introduction
1.1 INTRODUCTION
1.2 DISTRIBUTION IN POWER SYSTEM
1.3 DESIGN METHODOLOGY
Chapter 2 planning discerption
2.1 OUTLINE OF THE PROJECT
2.1.1.1 project description and specification
2.1.1.2 House Description
2.1.1.3 Architectural drawing
Chapter 3 service connection
Chapter 4 load Estimation
Chapter 5 calculation and cable selection
ELECTRICAL DISTRIBUTION DESIGN FOR HOUSE 1
Chapter 1 Introduction
PROJECT INTRODUCTION
2.2 INTRODUCTION
Power Distribution is one of the major duties of the electrical engineer. It requires
not only supplying the load points in the networks, but within strict measures of
safety, reliability, quality, in addition to these criteria, the economical factor is
considered as important issue, since limited resources is commonly faced in any
planning and design of project. Like any other industry.
2.3 DISTRIBUTION IN POWER SYSTEM
The electric power distribution system transports electric power from the
transmission or sub-transmission system to the customers. It includes primary
circuit, distribution sub-station, distribution transformer, secondary circuit and
appropriate control and protective devices. it is also the most visible part of the
supply chain, as such the most exposed to the critical observation of its users.
The purpose of the electrical distribution in modern residential cities is to provide
electrical design which will be completed with all schematic drawing.
Loads on a distribution system can be classified into four types, residential,
commercial, agricultural and industrial.
ELECTRICAL DISTRIBUTION DESIGN FOR HOUSE 2
Chapter 1 Introduction
2.4 DESIGN METHODOLOGY
Observe location dimensions
&
Start load Estimation
Lighting design by Design distribution panels
DIALUX and calculate and choose appropriate
lighting loads distribution arrangement
Choose the appropriate
transformer unit and backup Emergency lighting
generation and fire alarm designs,
capacities and
arrangements
Choose conductors sizes taking
all considerations in mind
Verify maximum
Verification of voltage drop
protection of
conductor Calculate short
circuit currents
Select protective
devices
Design earthing and
lightning protection
Wiring schemes
Design automatic
compensation plant
ELECTRICAL DISTRIBUTION DESIGN FOR HOUSE 3
Chapter 1 Introduction
2.5 DISTRIBUTION SYSTEM DESIGN
Distribution Systems Arrangements
The selection of system arrangement has a profound impact upon the goals of the
system discussed above. Several commonly used system topologies are presented
here, along with the pros and cons of each.
Simple Radial System
This system has only one path between each customer and the substation. There
is no duplication of equipment and hence system investment is the lowest of all
circuit arrangements. This arrangement is shown in Fig. Both the feeder and the
secondary systems are designed and operated radially.
The system offers the following advantages:
i. System investment cost is the least of all circuit arrangements.
ii. Simple in planning, design, and operation.
iii. Operation and expansion are simple.
iv. Coordination of protective devices is simple.
v. Simpler power flow and fault level calculations.
ELECTRICAL DISTRIBUTION DESIGN FOR HOUSE 4
Chapter 1 Introduction
vi. Because the entire load is served from a single source, full advantage can be taken of the
diversity among the loads. This makes it possible to minimize the installed transformer capacity.
The system offers the following disadvantages:
I. A fault in the supply circuit, the transformer, or the low voltage main bus will cause an
interruption of service to all loads. Service cannot be restored until the necessary repairs have been
made. Therefore, it is less reliable than other arrangements however, radial distribution systems, if
well designed and constructed, generally provide high levels of reliability provided plant is
reliable.
II. Equipment must be shutdown to perform routine maintenance and servicing.
III. The voltage regulation and efficiency of this system may be poor because of the low voltage
feeders and single source.
This system is suitable for smaller installations/loads where continuity of service is
not critical and where the need for low first-cost, simplicity, and space economy outweigh
the need for enhanced reliability.
ELECTRICAL DISTRIBUTION DESIGN FOR HOUSE 5
