IEC 61666:2010

Overview

IEC 61666:2010 is an international standard established by the International Electrotechnical Commission (IEC) that defines general principles for the identification of terminals within industrial systems, installations, equipment, and industrial products. This standard applies across various technical fields such as mechanical engineering, electrical engineering, construction engineering, and process engineering. Its scope covers systems leveraging different technologies or integrating multiple technologies.

The 2010 edition is a comprehensive technical revision of the original 1997 publication. It aligns its terminology with IEC 81346-1 Ed. 2, better describes terminal designation principles, and includes enhanced examples demonstrating terminal identification related to function, product, and location aspects. It also introduces the concept of terminal designation sets for improved clarity and system organization.

IEC 61666 holds the status of a horizontal standard, making it applicable across a broad range of industrial systems and ensuring consistency in the way terminals are identified within various contexts.

Key Topics

• Terminal Identification Principles
  The standard presents foundational rules to assign designations to terminals while considering aspects such as the product itself, the terminal's function, and its physical or logical location within a system.

• Terminology Consistency
  Terminology is harmonized with IEC 81346-1 Ed. 2, facilitating better integration with related standards and improving interoperability of documentation and system designs.

• Multi-Aspect Terminal Designation
  Terminal designations relate to:

  • Product aspect – referencing the physical equipment component.
  • Function aspect – reflecting the intended purpose or role of the terminal.
  • Location aspect – identifying the terminal’s position within an installation or cross-connection board.

• Terminal Designation Sets
  The standard introduces designation sets allowing consistent grouping and referencing of terminals from multiple aspects, enhancing clarity for system designers and maintenance personnel.

• Illustrative Examples
  Practical examples demonstrate how to apply identification principles to common industrial equipment such as motors and motor starters, helping users understand the mapping between real-world apparatus and their terminal designations.

• Classification of Terminals
  IEC 61666 includes guidance on categorizing terminals based on their structural and functional characteristics within a system.

Applications

IEC 61666 is vital for industries involved in the design, installation, operation, and maintenance of complex industrial systems that require precise terminal identification. Key applications include:

• Electrical and Mechanical Engineering
  Applying standard terminal identification methodologies to ensure clear and unambiguous wiring and connection mapping.

• Process Engineering and Automation
  Facilitating clear documentation and identification within systems combining various technologies such as electrical, pneumatic, and hydraulic components.

• System Integration and Maintenance
  Using standardized terminal designations to reduce errors, simplify troubleshooting, and improve operational safety during system commissioning and upkeep.

• Technical Documentation
  Harmonizing terminal labels and references across schematics, manuals, and digital system documentation improves communication among engineers and technicians globally.

Related Standards

• IEC 81346-1: Structuring Principles and Reference Designations
  Provides the foundational framework for system structuring and naming conventions, directly referenced in IEC 61666 for terminology consistency.

• IEC 60417: Graphical Symbols for Equipment
  Standardizes graphical representation supporting terminal identification and documentation.

• IEC 60445: Identification of Equipment Terminals
  Defines safety and identification principles for terminals and conductor terminations, complementing the designation focus of IEC 61666.

• IEC 60757: Code for Designation of Colours
  Supports visual identification schemes often associated with terminal labeling.

• IEC 61082-1: Preparation of Documents
  Establishes documentation rules valuable for presenting terminal identification information clearly.

• IEC 81714-3: Design of Graphical Symbols
  Addresses classification and encoding of connect nodes and networks, aligning with terminal identification practices.

Practical Value

Adopting IEC 61666:2010 ensures consistent and unambiguous terminal identification that supports:

• Enhanced system reliability by minimizing wiring and connection errors.
• Streamlined communication between design, installation, and maintenance teams internationally.
• Improved safety in industrial environments through clear and standardized terminal labeling.
• Compatibility with other IEC standards, facilitating a unified approach to industrial system documentation.
• Flexibility to apply across diverse industrial sectors and multi-technology systems.

By integrating IEC 61666 principles into industrial practices, organizations can achieve operational efficiency, reduced downtime, and compliance with global engineering standards.