3-Phase Line Fault Detection System with LL & LG Fault Indicator Using Timer IC and 7-Segment Display – Smart Power Protection Project Kit

Description

⚙️ Project Overview

The 3-Phase Fault Detection and Indicator Project is an intelligent protection system designed to monitor and detect faults in 3-phase electrical lines.
When a fault such as Line-to-Line (LL) or Line-to-Ground (LG) occurs, the circuit instantly identifies the fault type, isolates the affected line, and displays the fault on a 7-segment display.

This system provides students with hands-on experience in fault identification, power system protection, and circuit isolation concepts — key elements in modern industrial automation and power distribution systems.

⚡ Working Principle

The system monitors each phase of a 3-phase supply using sensing circuits connected through resistors and relay units.

1. Normal Condition:

   • All three phases (R, Y, B) are active and the output display shows a “Normal” condition.

2. Line-to-Line (LL) Fault Detection:

   • When two phases (e.g., R-Y or Y-B) short due to insulation failure or accidental connection, the circuit detects overvoltage/current changes.

   • A Timer IC (555-based delay circuit) processes the fault and displays “LL” on the 7-segment display.

   • A relay simultaneously isolates the affected line.

3. Line-to-Ground (LG) Fault Detection:

   • When one phase contacts the ground, leakage current is detected.

   • The Timer IC triggers a signal to display “LG” on the 7-segment indicator and disconnect the faulted line.

4. Fault Indication and Reset:

   • LED indicators and relays identify the faulted line (R, Y, or B).

   • A manual reset switch restores the circuit to normal operation once the fault is cleared.

This simulation demonstrates how real-world transmission and distribution networks identify and isolate faults to protect connected equipment.

🔩 Key Features

• Detects both Line-to-Line (LL) and Line-to-Ground (LG) faults.

• Uses Timer IC (NE555) for delay-based detection and control.

• 7-Segment Display shows real-time fault indication.

• LED fault indicators highlight affected phases (R, Y, B).

• Relay system provides line isolation during fault conditions.

• Compact design ideal for lab demonstrations and exhibitions.

• Fully assembled and tested kit with clear working explanation.

🧰 Technical Specifications

🎓 Educational Outcomes

Students will learn:

• Real-time 3-phase fault detection and protection techniques.

• Operation of Timer ICs in sequential fault timing applications.

• Relay operation and isolation mechanisms in electrical protection systems.

• 7-segment display interfacing and logic indication design.

• Power system safety and automation fundamentals.

This project provides practical exposure to power electronics, control systems, and electrical safety concepts vital for EV charging, transmission, and industrial automation systems.

💡 Applications

• Industrial and domestic 3-phase distribution fault protection.

• Substation monitoring and automatic isolation.

• Power transmission training and educational models.

• Electrical protection system design experiments.

• Smart grid safety demonstrations.

🧩 Advantages

• Protects equipment from short circuits and electrical damage.

• Identifies fault type and affected line accurately.

• Simple, low-cost, and reliable system.

• Easy fault indication with visual and digital display.

• Ideal for academic demonstrations and industrial simulations.

📦 Package Includes

• Fault Detection Main PCB with Timer ICs

• Relay and LED Indication Board

• Dual 7-Segment Display Board

• Power Transformer and Regulator Board

• Pre-wired connectors and test terminals

• Documentation (Word + PDF)

• Circuit and Block Diagram Images

• User Manual and Demonstration Guide