EN 62053-21 specifies particular requirements for static watt-hour meters of accuracy classes 1 and 2, intended for the measurement of alternating current electrical active energy in 50 Hz or 60 Hz networks. This standard outlines the constructional and performance requirements, including tests and conditions necessary to ensure accurate and reliable measurement under varying environmental conditions. It applies to newly manufactured meters and is relevant for residential, commercial, and light industrial use, ensuring that the meters meet defined accuracy and safety standards.