What is the recommended approach to fault-finding in a domestic installation?

• A. Randomly probe with a screwdriver.
• B. Replace all cables regardless.
• C. Use a methodical plan, check for known faults, isolate sections, measure continuity and insulation to locate faults.
• D. Only test at the main switch.

Answer: (C)

A methodical plan is how fault-finding should be approached in a domestic installation. Start with a structured sequence: identify and check known faults such as blown fuses or tripped protective devices, faulty outlets, or malfunctioning appliances. Then isolate sections of the circuit to prevent further issues or hazards. Use measurements to locate the fault: check continuity to confirm conductors are intact and connected, and perform insulation resistance tests to detect deteriorated or damaged insulation. By narrowing down the sections step by step and verifying with measurements, you can pinpoint where the fault lies, then repair and re-test the circuit to ensure safety and proper operation. This approach minimizes risk, avoids unnecessary work, and provides a reliable path to a safe fix.