Winding wires. Test methods. General
1Key Takeaways
This part of IEC 60851 specifies a general description of the test methods for winding wires. It also gives definitions of terms used in IEC 60851 (all parts). An overview of the contents of IEC 60851-2 to IEC 60851-6 is given in Annex A.
2Expert Interpretation
An in-depth interpretation of the BS EN IEC 60851-1:2021 winding wire testing standard, covering the technical requirements and implementation points of six major test modules such as dimensional measurement, mechanical properties, and chemical properties. It compares the main revisions of the 1996 version of the standard and provides guidance on testing solutions that comply with the UK BSI certification.
Analysis of the core content of the standard
BS EN IEC 60851-1:2021 is a general standard for winding wire test methods. It specifies the terminology definitions and basic test requirements for winding wires such as enameled wire and fiber-covered wire. This standard replaces the 1996 version of BS EN 60851-1. The main technical changes include:
| Version comparison dimensions | 1996 version | 2021 version |
|---|---|---|
| Normative references | Citations to old standards | Updated to the latest revision of the IEC 60851 series |
| Test atmospheric conditions | Humidity range not specified | Clear 25%-75% relative humidity requirement |
| Test management instructions | Not covered | New periodic test instructions |
Definition of key terms
Chapter 3 of the standard clearly defines 21 professional terms, among which special attention should be paid:
- Zero defect wire: Winding wire with no electrical discontinuity under specific test conditions
- Double coating: Insulation structure composed of two different materials, the base layer and the superimposed layer
- Thermal grade: The heat resistance of the wire characterized by the temperature index and the thermal shock temperature
Test method system
The standard constructs a complete test system through 6 volumes:
- IEC 60851-2: Dimension determination (including round wire, flat wire, and stranded wire measurement methods)
- IEC 60851-3: Mechanical properties (11 tests such as elongation, elasticity, and flexibility)
- IEC 60851-4: Chemical properties (4 tests such as solvent resistance and refrigerant resistance)
- IEC 60851-5: Electrical properties (5 tests such as breakdown voltage and dielectric loss)
- IEC 60851-6: Thermal properties (4 tests such as thermal shock and temperature index)
Implementation suggestions
When companies apply this standard, they should pay attention to the following:
Case: When a motor manufacturer accepts 0.5mm enameled round wire, it should give priority to the following:
- IEC 60851-2 Section 3.2.4 insulation increment test
- IEC 60851-3 Section 5.3 snap break test
- IEC 60851-5 Section 4.4 Breakdown voltage test
For periodic test items (items marked with *), it is recommended to negotiate with the customer to determine the test frequency. The typical cycle is:
- Solvent resistance test: quarterly or when raw materials are changed
- Temperature index test: annually or when the process is adjusted