Measuring earth leakage current requires a specialized instrument called an earth leakage clamp meter. It clamps around the earth conductor of the circuit and measures the current flowing through it. Acceptable levels for safety vary depending on regulations and application:
- IEC 60364-4-42: 30mA maximum for general residential installations.
- BS 7671: 30mA for most domestic circuits, 100mA for specific situations (e.g., bathrooms).