ITU-T Recommendations

An electricity supply voltage classified as extra-low voltage (ELV) has a low probability of causing a hazardous electrical shock. It is important to realise that the actual ELV value is not absolute but depends on the electrical shock event circumstances. Supplement 28 to ITU-T K-series Recommendations covers established definitions, insulation types, equipment classes, electric shock physical reaction levels, electric shock event factors and circuit configuration examples.