COURSE OVERVIEW:

Overcurrent protection is the most fundamental and widely applied protection technique in electrical distribution systems. This course provides a technical deep dive into the principles of "Inverse" and "Definite Time" protection, focusing on the coordination required to achieve maximum selectivity. Participants will explore the mechanics of "Time-Current Curves" (TCC), learning how to balance the need for fast fault clearance with the requirement to maintain power to healthy sections of the grid.

The scope of this training addresses the full spectrum of overcurrent applications, from simple low-voltage fuses to complex directional numerical relays in ring-main systems. It covers the technical nuances of "IDMT" (Inverse Definite Minimum Time) characteristics, focusing on the mathematical calculations for "Plug Setting Multiplier" (PSM) and "Time Multiplier Setting" (TMS). The curriculum provides a detailed focus on the coordination between upstream and downstream devices to prevent "Sympathetic Tripping."

Coverage includes the implementation of advanced overcurrent schemes, such as "Directional Overcurrent" and "Voltage-Restrained" protection. Attendees will learn to utilize software for protection coordination studies, interpret "Primary Injection" and "Secondary Injection" test results, and troubleshoot "Nuisance Tripping" caused by motor starting or transformer inrush. By combining protection theory with practical coordination exercises, the course equips professionals with the expertise required to design and maintain reliable overcurrent protection strings.

COURSE OBJECTIVES:

After completion of this course, the participants will be able to:

• Define the primary types of overcurrent: Overload, Short-Circuit, and Ground Fault.
• Differentiate between "Instantaneous" (50) and "Time-Delay" (51) elements.
• Select the appropriate "IDMT Curve" (Standard, Very, or Extremely Inverse).
• Calculate "Plug Setting Multiplier" (PSM) and "Time Multiplier Setting" (TMS).
• Achieve "Selective Coordination" using Time, Current, and Logic grading.
• Design "Directional Overcurrent" (67) schemes for parallel feeders.
• Implement "Sensitive Earth Fault" (SEF) protection for high-impedance paths.
• Coordinate "Fuses" with "Circuit Breakers" in industrial networks.
• Manage "Inrush Currents" for transformers and "Starting Currents" for motors.
• Perform "Secondary Injection" testing on overcurrent relays.
• Utilize "Primary Injection" to verify CT and protection circuit integrity.
• Troubleshoot "Selective Coordination" failures and nuisance trips.

TARGET AUDIENCE:

This course is intended for Protection Engineers, Electrical Designers, Commissioning Technicians, and Industrial Maintenance Personnel.

TRAINING COURSE METHODOLOGY:

A highly interactive combination of lectures, discussion sessions, and case studies will be employed to maximize the transfer of information, knowledge, and experience. The course will be intensive, practical, and highly interactive. The sessions will start by raising the most relevant questions and motivating everybody to find the right answers. The attendants will also be encouraged to raise more of their questions and to share in developing the right answers using their analysis and experience. There will also be some indoor experiential activities to enhance the learning experience. Course material will be provided in PowerPoint, with necessary animations, learning videos, and general discussions.

The course participants shall be evaluated before, during, and at the end of the course.

COURSE CERTIFICATE:

National Consultant Centre for Training LLC (NCC) will issue an Attendance Certificate to all participants completing a minimum of 80% of the total attendance time requirement.