IEC 60851.

Overview

IEC 60851 is the international series of test methods for winding wires — the insulated wires, usually enamelled, that are wound into the coils of motors, transformers, generators and other electromagnetic components. It defines how the properties of these wires are measured rather than setting the requirements themselves.

Winding wire has to be wound tightly, often by machine, without cracking its thin insulation, and then keep that insulation intact under heat and electrical stress for the life of the equipment. IEC 60851 provides the common, repeatable methods that let wire makers and users check these properties consistently.

Scope & Applicability

The series applies to round and rectangular winding wires across their dimensional, mechanical, electrical, thermal and chemical properties, with each property covered by its own part. A wire is characterised by selecting the parts relevant to its construction and intended use, so the standard supports both routine quality control and type characterisation.

Test Methods

The mechanical methods examine whether the wire and its insulation survive the stresses of winding:

• Flexibility and adherence — the wire is wound around a mandrel or jig and examined to confirm the insulation stretches with the conductor without cracking or peeling.
• Elongation and springiness — the wire is stretched to measure how far it elongates before breaking and how much it springs back, properties that affect how it behaves on winding machinery.

The mandrel diameters, elongation rates and acceptance criteria are defined by the relevant part of the standard, so the test apparatus is configured to the wire size under assessment.

Related Standards

IEC 60851 provides the test methods, while separate specification standards set the actual requirements a given class of winding wire must meet. The two are used together: the specification states the limits, and IEC 60851 defines how each limit is measured.

Testing with ULMEKA

ULMEKA Mechatronics designs and manufactures mechanical-property test apparatus for winding wires to IEC 60851, including mandrel-wrap and elongation checks, configured to the wire dimensions the standard defines. The equipment below covers these mechanical checks; for a specific testing need, the requirements are confirmed at the proposal stage.