The electrician calculates total loop resistance (~1.8 Ohms), forgets temperature rise, and assumes compliance.
If the loop impedance is too high, the fault current is too low. A low fault current means a circuit breaker or fuse will take too long—or fail entirely—to trip. During that delay, exposed metal parts can rise to dangerous touch voltages, causing electrocution or fire. earth fault loop calculator
This feature is part of our “Electrical Engineering in Practice” series, exploring the tools that keep modern infrastructure safe and reliable. The electrician calculates total loop resistance (~1