Course Syllabus: ET-313, Switchgear & Protective Devices

Semester / Session: 5th/Fall-2018

Instructor:                  Engr. Muhammad Imran Hashmi


                                    Phone: +92-334-5479184


                                    Office Hours:              0800hrs to 1600hrs


Course TA:                 N.A.

Course Description:   Students are introduced to the basics of Switchgear and Protective Devices for effective transmission continuity of electrical power.

Catalog Data:             Course Code:                           ET-313

                                    Course Title:                            Switchgear & Protective Devices

                                    Credit Hours:                           3+1

                                    Course Designation:                 Compulsory

                                    No of Sessions per week:        1 (Total 16 sessions)

                                    Session Duration:                     180 minutes

Catalog Description:  ET-313, Switchgear & Protective Devices, Credits (3+1)

Switchgear and Protection Devices, Fuses, Switches, Circuit Breakers, Protective Relays, Protection of Alternator, Transformer, Bus-Bars and Lines, Protection against over-load, short-circuit and over voltage.

Prerequisite:               NIL

Prerequisites byTopics:  NIL

Co-requisite:               NIL

Textbook:                    V. K. Mehta, “Principles of Electrical Power Systems”.

                                        References:                 1. The Art and Science of Protective Relaying, Vol I and II.

                                      2. Turan Gonen, "Electrical Power Distribution System", Latest Edition.

Program Learning Outcome: This course is designed in conjunction with the following PLOs.

PLO 1. Engineering Knowledge: An ability to apply knowledge of mathematics, science, engineering fundamentals and an engineering specialization to the solution of complex engineering problems.

PLO 2. Problem Analysis: An ability to identify, formulate, research literature, and analyze complex engineering problems reaching substantiated conclusions using first principles of mathematics, natural sciences and engineering sciences.

                                   Course Learning Outcome (CLO): Upon successful completion of this course, the student will be able to:

CLO 1. Understand switchgear and protective devices and analyze their types as per their performance and pros & cons.                                                                                         [Congnitive-4]

CLO 2.  Analyze different types (circuit breakers, fuses and protective relays) of equipment used in switchgear system in terms of their construction, principle of operation and construction and technical features.                                                                                                            [Congnitive-4]

CLO 3. Understand and analyze the utilization of protective devices for protection of power system equipment as well as faults in power system.                                                        [Congnitive-4]


                 Mapping of CLOs to PLOs and Learning Domains:                    

Course Learning Outcome

Program Learning Outcome

Learning Domain



Cognitive 4



Cognitive 4



Cognitive 4


Course Professional Outcome/ Industrial Usage: This course is an introductory course on Switchgear & Protective Devices. It is designed for students in engineering and utilization of protective equipment. It introduces students to the switchgear system and varieties of protective equipment, and analyses the problems that may arise within the context.

Course Outline and Sessions Breakdown:  I. Switchgear System (CLO-1)                                   (2 Sessions)

Switchgear, essential features of switchgear, switchgear equipment, bus-bar arrangement, switchgear accommodation, short circuits and short circuit currents.

II. Circuit Breakers and Fuses (CLO-2)                                    (5 Sessions)

Principle of operation of circuit breaker, arc in circuit breakers, zero current-interruption theory, types of circuit breaker, oil, air-blast, SF6, and vacuum circuit breaker, recovery and re-striking voltage, rate of rise of re-striking voltage, rating of circuit breakers. Fuses, elements of fuse, inverse current-time characteristics, characteristics of fuse element, comparison of fuse and circuit breaker.

III. Protective Relays (CLO-2)                                    (4 Sessions)

Purpose and functions of relays, basic requirement of protective relaying, types of relays, electromagnetic attraction relays, induction relays, distance or impedance relays, differential relays.

IV. Protection of Power System (CLO-3)                                    (5 Sessions)

Protection of Alternators and Transformers, protection of Bus-Bars and Transmission Lines, protection against over voltages, neutral grounding.

Computer Usage:       Not applicable unless otherwise stated.

Projects /Design Activities:        Students will be asked to analyze a complex engineering problem.

Evaluation Criteria:   1. Assignments                       10%

                                    2. Quizzes                              10%

                                    3. Mid-Term Exam                  30%

         4. Final Exam                          50%


  1. No make up tests or quizzes, except in case of emergency, e.g. illness and accident. For make up tests, medical certificate is required and the instructor must be notified in advance of the test.
  2. No late assignment will be accepted.


Course Material