Overcurrent & Earth Fault Protection

Objectives
• Understand OC and EF protection principles.
• Learn relay coordination and grading.
• Apply directional protection concepts.

Key Topics
• 50/51 and 50N/51N protection.
• Time-current characteristics and grading.
• Directional earth fault (DEF).
• Relay setting philosophy.

Practical Focus
• Grading calculation example.
• Coordination study between feeders.

Suggested Diagrams
• TCC curve diagram.
• Directional protection scheme

Key Takeaways
• Ability to set and coordinate OC/EF relays.
• Understanding selectivity and backup.

Standards & References
• IEC 60255-151.
• IEEE C37.112.
• SSEN and NG standards.

Certification & Delivery
• Certificate of Completion awarded.
• Delivery Mode: Online (On-demand).
• Corporate and customized training available on request.

Prerequisites:
• Familiarity with substation primary equipment (disconnectors, circuit breakers,        earth switches).