IEC 60851-4:2016

Overview

IEC 60851-4:2016 is an international standard published by the International Electrotechnical Commission (IEC) focusing on the chemical properties test methods for winding wires used in electrical equipment. This part of the IEC 60851 series specifies four key chemical property tests for enamelled winding wires, including resistance to solvents, refrigerants, solderability, and resistance to transformer oil. The standard provides detailed procedures and testing conditions that ensure winding wires meet strict quality and durability requirements for electrical and electronic applications.

This third edition, published in 2016, supersedes earlier editions from 1996 and amendments from 1997 and 2005. It incorporates significant revisions to resistance to refrigerants and solderability tests, and introduces a new informative annex for alternative refrigerants to monochlorodifluoromethane (R 22).

Key Topics

Chemical Properties Tests Included

• Test 12: Resistance to Solvents
  Measures the durability of enamel coatings on winding wires against chemical solvents, using a pencil hardness test method after solvent exposure. This test applies primarily to enamelled round wires with conductor diameters over 0.25 mm and to enamelled rectangular wires.

• Test 16: Resistance to Refrigerants
  Evaluates the impact of refrigerants on winding wire insulation, including chemical extraction and electrical breakdown voltage tests. This test helps confirm that wires maintain insulation integrity when exposed to refrigerants common in electrical and HVAC systems.

• Test 17: Solderability
  Assesses the ability of winding wire surfaces to be effectively soldered, ensuring reliable electrical connections. The test verifies adhesion and wetting of solder on wire surfaces, essential for wire winding processes in motors and transformers.

• Test 20: Resistance to Transformer Oil
  Determines the stability of wire enamel coatings when immersed in transformer oils used in high voltage transformers and switchgear. The test focuses on resistance to hydrolysis and oil-induced degradation, vital for long-term reliability.

Revisions and Updates

• Updated methodologies for assessing resistance to refrigerants and solderability reflect current industry needs and environmental considerations.
• Annex A introduces alternatives to the refrigerant R 22, addressing environmental regulations and the use of eco-friendlier substances.

Normative References

The standard references important related documents, such as IEC 60296 for insulating mineral oils, IEC 60851-1 for general test methods, IEC 60851-3 and 5 for mechanical and electrical properties, and ISO 9453 for solder alloy specifications. These interconnected standards ensure a comprehensive approach to winding wire quality assessment.

Applications

IEC 60851-4:2016 is vital in a range of industries and applications where electrical winding wires are essential, such as:

• Electric motors and generators
  Ensures wires retain chemical resistance and solderability despite exposure to solvents and refrigerants in motor environments, prolonging motor life and performance.

• Transformers and switchgear
  Confirms wire coatings withstand transformer oil exposure, preventing insulation breakdown and electrical failures.

• HVAC systems
  Validates that winding wires maintain insulation integrity when in contact with various refrigerants, aligning with environmental standards.

• Electrical equipment manufacturing and quality control
  Provides manufacturers and suppliers with standardized test methods to certify product compliance and improve production processes.

Using IEC 60851-4 chemical testing methods helps manufacturers guarantee the durability, reliability, and safety of winding wires, which is crucial for electrical device efficiency and lifespan.

Related Standards

• IEC 60851 Series – Comprehensive series covering all test methods for winding wires, including mechanical (Part 3) and electrical properties (Part 5).
• IEC 60317 Series – Specifications for particular types of winding wires, complementing the test methods with product standards.
• IEC 60264 Series – Standards covering packaging of winding wires to maintain quality during transport and storage.
• ISO 9453 – Specifications for solder alloys used in solderability tests, important for consistent test outcomes.
• IEC 60296 – Standards for mineral insulating oils, referenced in tests evaluating resistance to transformer oil.

Conclusion

IEC 60851-4:2016 defines rigorous chemical property test methods essential for evaluating the performance and durability of enamelled winding wires in electrical applications. By adhering to these international standards, manufacturers and users can ensure their winding wires exhibit excellent chemical resistance, solderability, and long-term stability in solvents, refrigerants, and transformer oils. These tests help improve electrical equipment reliability, safety, and conformity with environmental regulations - making IEC 60851-4 a key resource in the electrotechnical industry.