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CSA C49.5-10 (2015): Aluminum Alloy 1350 Round Wire for Electrical Purposes – Specification Overview and Compliance
A comprehensive guide to the Canadian Standards Association standard for electrical-grade aluminum wire, covering material requirements, mechanical properties, and testing procedures.
1. Scope and Field of Application
CSA C49.5-10 (2015) defines the requirements for round aluminum wire of alloy 1350 (also known as AA1350 or EC grade aluminum) intended for use as electrical conductors. The standard covers wire with nominal diameters from 0.400 mm to 4.000 mm (or equivalent cross-sectional areas) in bare form or with metallic coatings such as tin or silver. It is widely referenced by Canadian electrical utilities and cable manufacturers for applications including bare overhead conductors, neutral messengers, building wire, magnet wire, and automotive wiring where weight reduction is critical.
The standard specifies material designation, chemical composition limits, mechanical properties (tensile strength and elongation), maximum electrical resistivity, dimensional tolerances, and test methods. It also provides guidance on sampling procedures, product marking, and certification to ensure consistency and quality for safety-critical electrical infrastructure.
2. Technical Requirements
2.1 Material Designation and Chemical Composition
Alloy 1350 is a controlled high-purity aluminum with a minimum aluminum content of 99.50% by mass. Impurities are strictly limited to maintain high electrical conductivity and ductility. Table 1 summarizes the chemical composition limits as per CSA C49.5-10.
| Element | Composition (mass %) |
|---|---|
| Aluminum (Al) | 99.50 min |
| Iron (Fe) | 0.40 max |
| Silicon (Si) | 0.10 max |
| Copper (Cu) | 0.05 max |
| Each other element | 0.03 max |
| Total others (excluding Fe, Si, Cu) | 0.10 max |
2.2 Mechanical Properties
The standard recognizes three common tempers: H12 (strain-hardened, quarter-hard), H14 (half-hard), and H16 (three-quarter-hard). Minimum tensile strength and elongation vary with wire diameter and temper. For example, for wire diameters up to 2.000 mm in H14 temper, the tensile strength shall be between 115 MPa and 140 MPa, with a minimum elongation of 1.5% in a 250 mm gauge length. Table 2 of the standard provides detailed values; the following is illustrative for H14 temper.
| Diameter (mm) | Tensile Strength (MPa) | Elongation in 250 mm (%) |
|---|---|---|
| 0.400 – 1.000 | 115 – 140 | 1.5 |
| 1.001 – 2.000 | 110 – 135 | 2.0 |
| 2.001 – 4.000 | 105 – 130 | 3.0 |
Caution: Mechanical properties are temper-specific. Any annealing or improper thermal exposure can reduce tensile strength and elongation below standard limits, compromising performance in bending or cyclic loading. Always verify temper designations on the product certificate.
2.3 Electrical Resistivity and Conductivity
Conductivity of Alloy 1350 wire shall be not less than 61.0% IACS (International Annealed Copper Standard) at 20°C. This corresponds to a maximum resistivity of 0.028264 Ω·mm²/m (0.028264 µΩ·m). The standard requires measurement on a full-section sample using a Kelvin bridge (four-wire method) or an equivalent precision method, corrected to 20°C.
2.4 Dimensional Tolerances
For wire diameters up to 4.000 mm, the diameter tolerance is ±2% of the nominal diameter. The ovality (maximum difference between two perpendicular diameter measurements at any cross-section) shall not exceed 1% of the nominal diameter. These tolerances ensure consistent cross-sectional area and current-carrying capacity.
3. Implementation and Compliance
3.1 Sampling and Testing
For lot acceptance, a random sample of three coils or spools is selected. If any test fails, a retest of six coils (double the original sample) is permitted. Chemical composition is verified via spectrometric or wet chemical methods. Tensile tests are performed at a crosshead speed of 25 mm/min using a suitable gauge length (250 mm for small wires). Electrical resistivity is measured at 20°C ± 1°C with a temperature correction factor of 0.0039 /°C.
3.2 Certification and Marking
Manufacturers shall provide a certificate of compliance stating the standard number, alloy, temper, nominal diameter, and test results. Each coil or spool must be marked with the standard designation (CSA C49.5-10), heat number, and net mass. Third-party certification by an accredited body (e.g., CSA Group) is not mandatory unless required by regulation or contract, but many purchasers demand it for critical infrastructure.
Tip: When procuring aluminum wire for Canadian overhead distribution projects, many utilities explicitly require conformance to CSA C49.5-10. Requesting a Certificate of Compliance with each shipment helps streamline acceptance.
3.3 Common Compliance Pitfalls
- Confusion with ASTM B233: CSA C49.5-10 is technically harmonized with ASTM B233 but includes unique marking and tolerance notes. Always verify local utility requirements.
- Improper storage: Exposure to moisture or corrosive environments can degrade surface quality and increase contact resistance. Store in dry, covered conditions.
- Temper mis-specification: Using H14 wire where H16 is required may result in insufficient strength for sag calculations in long spans.
Warning: Non-compliant elongation (below minimum values) can lead to conductor breakage during installation or under ice/wind loads. Always verify test reports for elongation, especially for smaller diameters.
Best Practice: Compliance with CSA C49.5-10 ensures a high-quality conductor with consistent electrical and mechanical performance. Adopting the standard in procurement specifications reduces field failures and extends asset life.
4. Frequently Asked Questions
Q: What are the most common uses for wire specified under CSA C49.5-10?
A: Typical applications include bare overhead distribution conductors (e.g., AAC, AAAC), neutral messengers, building wire, magnet wire for transformers, and aluminum automotive wiring harnesses where weight reduction is needed.
A: Typical applications include bare overhead distribution conductors (e.g., AAC, AAAC), neutral messengers, building wire, magnet wire for transformers, and aluminum automotive wiring harnesses where weight reduction is needed.
Q: Does CSA C49.5-10 apply to stranded conductors or only solid round wire?
A: The standard covers only round wire (solid) used as raw material for stranded conductors. Stranded cable constructions have their own standards (e.g., CSA C49.6 for bare aluminum stranded conductors).
A: The standard covers only round wire (solid) used as raw material for stranded conductors. Stranded cable constructions have their own standards (e.g., CSA C49.6 for bare aluminum stranded conductors).
Q: What is the difference between CSA C49.5-10 and ASTM B233?
A: CSA C49.5-10 is the Canadian adoption of the same wire specification but includes additional requirements for product marking, certification, and some increased tensile strength minima for certain sizes. Both standards are largely equivalent, but Canadian utility specifications often mandate the CSA version.
A: CSA C49.5-10 is the Canadian adoption of the same wire specification but includes additional requirements for product marking, certification, and some increased tensile strength minima for certain sizes. Both standards are largely equivalent, but Canadian utility specifications often mandate the CSA version.
Q: Can CSA C49.5-10 wire be welded or brazed?
A: Yes, Alloy 1350 has good weldability and brazeability. However, welding may anneal the wire locally, reducing strength. The standard does not restrict joining methods, but post-weld heat treatment may be required if original temper properties must be maintained near joints.
A: Yes, Alloy 1350 has good weldability and brazeability. However, welding may anneal the wire locally, reducing strength. The standard does not restrict joining methods, but post-weld heat treatment may be required if original temper properties must be maintained near joints.