Alternating current static watt-hour meters for active energy (classes 1 and 2)

This specification defines the technical requirements for instruments measuring active energy in alternating current systems, specifically tailored for metering purposes with accuracy classes 1 and 2. It establishes the fundamental metrological characteristics, test procedures, and performance criteria necessary to ensure reliable operation across diverse electrical networks. The document outlines the permissible error limits under defined reference conditions, covering aspects such as starting current, sensitivity, and burden capacity. Furthermore, it addresses environmental influences including temperature variations and voltage fluctuations, ensuring consistent measurement accuracy throughout the instrument's operational life. Detailed guidelines on construction, markings, and protection against unauthorized changes are provided to maintain integrity and safety. By adhering to these provisions, manufacturers can produce devices that meet rigorous quality standards, facilitating uniformity in energy consumption recording. The scope extends to both single-phase and poly-phase arrangements, applying to static and electromechanical types used for domestic, commercial, and industrial applications. Compliance with these guidelines supports the accurate billing and monitoring of energy usage, forming a critical component of modern electrical infrastructure management without making subjective assessments of its necessity or impact.