IEC 60721-2-2:2012

Overview

IEC 60721-2-2:2012 is an international standard published by the International Electrotechnical Commission (IEC) that classifies environmental conditions related to precipitation and wind. Specifically designed for electrotechnical products, this standard presents fundamental properties, key parameters for characterization, and a systematic classification of natural environmental conditions involving rain, hail, snow, and wind. It assists manufacturers and engineers in selecting appropriate environmental severities when designing and testing electrotechnical equipment to ensure durability and reliability under varied weather conditions.

The 2012 edition is a technical revision of the 1988 version, featuring simplified and updated content to reflect validated data and modern terminologies. It enhances clarity on precipitation mechanisms and wind forces, aligning definitions with recognized meteorological sources.

Key Topics

• Precipitation Classification
  Covers types of precipitation including normal rain, driving rain, hail, snow, and formation of ice (air hoar, rime, clear ice, glaze ice). The standard details the physical characteristics such as rain intensity, drop size distribution, falling velocity, and typical temperatures associated with rain and other hydrometeors.

• Wind Characteristics
  Describes wind as the horizontal movement of the atmosphere, influenced by pressure gradients and the Earth's rotation (Coriolis force). The standard distinguishes between various wind phenomena from breezes and gales to hurricanes, emphasizing their impact on electrotechnical product environments.

• Environmental Parameter Severities
  Provides a basis for understanding relevant severities in precipitation and wind parameters, aiding users in applying the appropriate class when specifying product requirements in accordance with IEC 60721-1.

• Updated Formulations and Data
  Introduces new formulas for impact energy relating to hail and revised classification criteria for wind force, driving rain, and snow, ensuring harmonization with international meteorological datasets.

Applications

• Product Design and Testing
  Engineers use IEC 60721-2-2 to determine environmental stressors from precipitation and wind that electrotechnical products will encounter. These conditions influence materials selection, protective coatings, sealing requirements, and mechanical reinforcement.

• Environmental Risk Assessment
  Enables manufacturers to assess exposure risks in different geographic locations and climates, including regions prone to heavy snowfall, intense hailstorms, or strong prevailing winds, ensuring compliance with safety standards.

• Standards Compliance and Certification
  Serves as a reference for certification bodies and testing laboratories gauging product performance limits against classified environmental conditions, forming part of conformity assessment procedures.

• Infrastructure and Outdoor Equipment
  Influences design standards for outdoor electrical installations, transmission equipment, street lighting, and renewable energy systems exposed to precipitation and wind, ensuring operational stability and longevity.

Related Standards

• IEC 60721-1: Classification of Environmental Conditions – Part 1
  Defines environmental parameters and their severities, providing complementary guidance for selecting appropriate classes of environmental influence for product testing.

• IEC 60068 Series: Environmental Testing
  Contains methods for testing electrotechnical products against various environmental stresses, including those related to moisture, temperature, and mechanical forces, building upon the classifications given in IEC 60721.

• ISO Meteorological Standards
  Many of the definitions and parameters in IEC 60721-2-2 align with ISO climate-related standards and international meteorological datasets to ensure global relevance and applicability.

Keywords: IEC 60721-2-2, environmental classification, precipitation classification, wind classification, electrotechnical product standards, rain intensity, hail impact energy, snow load, driving rain, wind force, environmental conditions standard, IEC environmental testing.