IoT-Based Underground Cable Fault Detection

When an underground power cable faults, utilities today dig up entire road stretches hunting for the break — expensive, slow, and disruptive. This project pinpoints the fault from the surface: an ESP32-based unit injects a test signal into the cable, measures the resulting line resistance, and computes the fault distance in kilometers using the cable's resistance-per-km constant. The phase and distance show on an LCD and push to a cloud dashboard with alerts. Underground cable fault detection is a classic high-volume EEE student search — three sellers already monetize it with thin WooCommerce pages and stale Arduino+GSM designs. This is the modern ESP32 + cloud rebuild that outranks them.

1. The cable is modeled as a resistor ladder; each kilometer of cable contributes a known resistance.
2. The ESP32 injects a low-voltage test signal through a relay-switched circuit into the suspect cable.
3. An ADC measures the loop resistance; the firmware divides by the calibrated ohm-per-km constant to compute fault distance.
4. The faulted phase is identified by testing each phase in sequence; results display on the LCD instantly.
5. Readings are pushed to the cloud dashboard and an SMS/push alert fires with phase + distance, so the repair crew digs at one spot, not the whole road.

Features:

• Fault distance calculation from line-resistance measurement (Murray/Varley loop principle, simplified for demo)
• Three-phase cable support — identifies which phase faulted (R/Y/B)
• 16x2 LCD showing faulted phase + distance in kilometers
• Cloud dashboard (ThingSpeak/Blynk) with fault history and location log
• SMS/push alert on fault detection with phase and distance
• Simulated fault switches — create faults at known distances to demo and calibrate
• Relay-based cable switching for safe test-signal injection
• Calibration mode: set the cable's ohm-per-km constant for accurate readings

What's included:

• Complete ESP32 firmware with full source code
• Circuit diagram and PCB-ready wiring layout
• Calibration procedure for the ohm-per-km constant
• Project report PDF (synopsis, fault-location theory, design, testing, results)
• Presentation PPT for review/demo day
• Viva Q&A sheet covering cable faults, Murray loop, and IoT architecture
• Demo script: injecting faults at known distances and verifying readings