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CAN CSA C61089-11 (2016): Overhead Electrical Stranded Conductors – Technical Overview and Compliance
Understanding the Canadian adoption of IEC 61089 for round wire concentric lay stranded conductors used in overhead power lines
Scope and Application
CAN CSA C61089-11 (2016) is the Canadian adoption of the international standard IEC 61089 (1991) with prescribed Canadian deviations. It specifies requirements for round wire concentric lay stranded overhead electrical conductors made of aluminum, aluminum alloy, and steel-reinforced combinations (ACSR, AAC, AAAC, etc.). The standard covers conductors for use in overhead power transmission and distribution lines where the conductor is exposed to atmospheric conditions.
The standard applies to bare conductors only and does not cover covered or insulated conductors. It defines conductor constructions from Class A (compact) through Class G (extra flexible) and includes requirements for materials, stranding, joints, protective coatings, and mechanical/electrical properties. It is referenced by Canadian electrical utilities and manufacturers to ensure uniformity and reliability of overhead conductors.
Key Adoption Context: CAN CSA C61089-11 (2016) replaces the earlier CAN CSA C49.1 and C49.2 standards for aluminum and ACSR conductors, harmonizing with international practice while retaining specific Canadian requirements for corrosion protection, stranding tolerances, and test methods.
Technical Requirements
Conductor Classification and Stranding
The standard classifies conductors based on the number and arrangement of strands. The most common construction is concentric lay, where a central wire is surrounded by one or more layers of helically laid wires. Each subsequent layer has six more wires than the previous layer. The standard permits variations for compact and shaped wire designs.
| Class | Description | Typical Strand Counts | Application |
|---|---|---|---|
| A | Compact round wire (drawn) | 7, 19, 37, 61, 91 | Urban distribution, limited sag |
| B | Standard concentric lay | 7, 19, 37, 61 | General transmission |
| C | Large number of strands | 91, 127 | High-capacity lines |
| D | Extra flexible (many strands) | 259, 427 | Vibration-prone spans |
Material Specifications
Materials must conform to the corresponding material standards:
- Aluminum (1350-H19): CSA C61089-11 references ASTM B230 for aluminum wire. Tensile strength minimum 159–200 MPa depending on diameter.
- Aluminum alloy (6201-T81): Per ASTM B398, with minimum tensile strength 317 MPa.
- Steel core (galvanized): Per ASTM B498 (Class A, B, or C coating). Zinc coating mass must meet minimums based on wire diameter and service environment.
Canadian Deviation: Clause 5.1.2 of CAN CSA C61089-11 requires that all steel core wires be furnished with Class C zinc coating (heavy) unless otherwise specified by the purchaser. This exceeds the IEC baseline to improve corrosion resistance in Canadian climates with road salt and coastal exposure.
Mechanical and Electrical Performance
The standard defines rated tensile strength (RTS) for each conductor construction. The RTS is computed from the sum of the strengths of all individual wires, multiplied by a stranding factor (typically 0.93–0.97 for concentric lay). Electrical resistance is specified at 20°C per unit length (DC resistance). Table 2 summarizes typical values for common conductor sizes.
| Conductor Code | Stranding (Al/St) | Diameter (mm) | RTS (kN) | DC Resistance at 20°C (Ω/km) |
|---|---|---|---|---|
| Hawk | 26/7 | 21.79 | 82.5 | 0.1391 |
| Drake | 26/7 | 28.14 | 139.0 | 0.0832 |
| Cardinal | 54/7 | 30.16 | 173.5 | 0.0725 |
Joints and splices are permitted only under controlled factory conditions; field splices in the conductor body (not in connections) are generally prohibited. Each completed conductor must be free of surface imperfections such as scratches, die marks, and excessive burrs.
Implementation Highlights
Procurement and Quality Assurance
Purchasers should specify the conductor class, size (or code word), and any special requirements such as corrosion protection or vibration dampers. CAN CSA C61089-11 requires that the manufacturer provide a certificate of compliance with each delivery. Acceptance testing includes:
- Visual and dimensional inspection of strands and finished conductor
- Stranding lay length and direction verification
- Tensile test on individual wires and on the completed conductor
- Resistance measurement
- Zinc coating weight and adhesion test for steel core
Installation Tip: When stringing conductors conforming to CAN CSA C61089-11, always use proper pulling grips that do not over-compress the strands. The standard’s tolerance for strand gaps (typically within ±3% of nominal) can be affected by improper tension during installation.
Coordination with Other Standards
CAN CSA C61089-11 works within a family of CSA and IEC standards. It references CSA C22.2 No. 0 for general electrical safety, IEC 60104 for aluminum-magnesium-silicon alloy wires, and IEC 61232 for aluminum-clad steel wires. For conductor accessories (clamps, dead-ends, etc.), refer to CSA C60068-1. Engineers should also be aware of the Canadian Electrical Code, Part I (CSA C22.1) where ampacity tables for these conductors are provided.
Compliance and Testing Notes
Third-Party Certification
Many Canadian utilities require that conductors be listed by a recognized certification body (e.g., CSA Group, UL). CAN CSA C61089-11 can be used as the basis for such certification. Manufacturers must maintain a quality control system that verifies material traceability and ensures that each conductor lot meets the standard’s requirements.
Critical Compliance Requirement: Clause 8.6 of CAN CSA C61089-11 mandates that the manufacturer perform a salt-spray corrosion test on galvanized steel core wires when ordered for coastal or industrial environments. Failure to pass this test (based on ASTM B117 for 96 hours) results in rejection of the entire lot.
Common Non-Conformances
During factory inspections and field installations, the following issues are frequently noted:
- Lay length deviation: The lay length (pitch) of the outer layer must be between 10 and 14 times the nominal diameter. Deviation outside this range can cause birdcaging or reduced fatigue life.
- Insufficient zinc coating: Class C coating requires minimum 315 g/m² for wire diameters > 2.67 mm. Test results below this threshold must be rejected.
- Strand gaps: Helical gaps between strands shall not exceed 0.5 mm for conductors under 30 mm diameter. Larger gaps may permit moisture ingress and corrosion.
Documentation
Each manufacturer shall provide a datasheet including conductor drawing, stranding table, electrical resistance, rated tensile strength, mass per unit length, and shipping length. The datasheet must be anchored to the standard’s requirements and note any deviations requested by the purchaser.
Q: Does CAN CSA C61089-11 (2016) cover all types of overhead conductors?
A: No. It covers round wire concentric lay stranded conductors made of aluminum, aluminum alloy, and steel-reinforced combinations. It does not cover covered or insulated conductors, nor conductors using shaped wire (trapezoidal) or self-damping designs, which have their own standards (e.g., CAN CSA C49.3 for compact trapezoidal wire).
A: No. It covers round wire concentric lay stranded conductors made of aluminum, aluminum alloy, and steel-reinforced combinations. It does not cover covered or insulated conductors, nor conductors using shaped wire (trapezoidal) or self-damping designs, which have their own standards (e.g., CAN CSA C49.3 for compact trapezoidal wire).
Q: How does CAN CSA C61089-11 differ from the original IEC 61089?
A: The Canadian adoption includes several national deviations: mandatory Class C zinc coating for steel core wires, additional salt-spray testing for corrosion resistance, modified stranding tolerances for certain sizes, and references to Canadian material standards (e.g., CSA G40.21 for steel, CAN/CSA C22.2) instead of IEC material standards.
A: The Canadian adoption includes several national deviations: mandatory Class C zinc coating for steel core wires, additional salt-spray testing for corrosion resistance, modified stranding tolerances for certain sizes, and references to Canadian material standards (e.g., CSA G40.21 for steel, CAN/CSA C22.2) instead of IEC material standards.
Q: What is the significance of the 2016 edition of this standard?
A: The 2016 edition reaffirmed the technical content of the previous edition (2008) with minor editorial corrections. It also updated references to other Canadian standards (e.g., CAN CSA C22.2 No. 0). It remains the current version at the time of writing (2026).
A: The 2016 edition reaffirmed the technical content of the previous edition (2008) with minor editorial corrections. It also updated references to other Canadian standards (e.g., CAN CSA C22.2 No. 0). It remains the current version at the time of writing (2026).
Q: Can I use this standard for conductor sizes not listed in the tables?
A: Yes. The standard provides formulas and rules for computing values for any size combination of strands. However, any new construction should be submitted for evaluation by the purchaser and may require additional testing to demonstrate compliance.
A: Yes. The standard provides formulas and rules for computing values for any size combination of strands. However, any new construction should be submitted for evaluation by the purchaser and may require additional testing to demonstrate compliance.
© 2026 – This article is provided for informational purposes. Technical decisions should always reference the current official version of CAN CSA C61089-11 published by the Canadian Standards Association.