Insulation Resistance

Insulation resistance is one of the core indicators of the safety performance of electrical products. It refers to the ability of insulating materials to prevent current from passing through after a DC voltage is applied, usually measured in megohms (MΩ). In foreign trade, this term is commonly found in technical specifications, contract clauses, and quality inspection reports for products such as wires and cables, motors, transformers, and household appliances. Usage scenarios include: customers requesting insulation resistance test reports, agreeing on a minimum insulation resistance value (e.g., ≥100MΩ), or using it as an acceptance criterion. Note: Different standards (such as IEC, UL, GB) have different requirements for test voltage, measurement time, and acceptable values, so the referenced standard number must be clearly stated in the contract; also, insulation resistance must be distinguished from the dielectric withstand test (Hi-Pot)—the former measures insulation performance, while the latter tests insulation strength. Unlike 'conductor resistance,' insulation resistance concerns the insulating layer rather than the conductor itself. Foreign trade practitioners should ensure that the test data provided by suppliers meets the requirements of the importing country to avoid returns or claims caused by non-compliant indicators.