IEC 60317-27-1:2020

Overview

IEC 60317-27-1:2020 - Specifications for particular types of winding wires - Part 27-1: Paper tape covered round copper wire - defines the requirements for round copper conductors covered with two or more layers of paper tape. The covering is primarily intended for winding coils for oil‑immersed transformers. The standard covers nominal conductor diameters from 0.500 mm up to and including 5.000 mm and restricts paper tape types to those specified in IEC 60554-1 and IEC 60554-3-5.

Key topics and technical requirements

• Covering composition: Paper tape covering made of two or more layers; paper types limited to IEC 60554 series materials.
• Dimensions: Nominal conductor diameters follow IEC 60317-0-1; the standard specifies the required increase in diameter caused by the paper tape covering and defines the maximum overall diameter (conductor + covering). Increase-in-diameter tolerances are given in the standard (Table 1) and must be agreed between purchaser and supplier.
• Appearance: Conductor must be essentially free from copper dust and contaminants on the original spool/reel. Paper tapes must be wrapped firmly, closely, evenly and continuously. No adhesives except for anchoring tape ends.
• Electrical and mechanical references: Electrical resistance and elongation tests refer to IEC 60317-0-1 (and its amendment). Other mechanical properties such as flexibility and adherence are to be agreed case-by-case because paper thickness and tape count vary.
• Tests noted as inappropriate or conditional: Several standard windings tests (e.g., heat shock, cut‑through, resistance to solvents, breakdown voltage, solderability) are flagged as “test inappropriate” for this product form; test applicability should be confirmed between purchaser and supplier.
• Ordering information: When specifying wire, include the standard reference, nominal conductor diameter (mm) and nominal increase due to paper (example format: IEC 60317-27-1 3,200 + 0,30).

Applications

• Designed primarily for winding coils in oil‑immersed power transformers where paper tape covering provides mechanical protection and dielectric separation.
• Suitable for transformer manufacturers, rewind shops and specialized winding operations that require paper‑insulated round copper conductors.

Who should use this standard

• Transformer designers and manufacturers
• Winding wire producers and suppliers
• Procurement and quality engineers specifying wire for oil‑filled transformer coils
• Test laboratories and conformity assessors referencing winding‑wire specifications

Related standards

• IEC 60317-0-1 (General requirements for enamelled round copper wire)
• IEC 60554-1 and IEC 60554-3-5 (specifications for cellulosic papers for electrical purposes)
• IEC 60851 series (winding wires - test methods)
• IEC 60264 series (packaging of winding wires)

This standard ensures consistent dimensional, appearance and material characteristics for paper tape covered round copper wire, facilitating reliable transformer winding performance and supplier–purchaser agreement.