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CAN CSA C22.2 No. 65-18: Wire Connectors Safety Standard
Technical overview of the Canadian standard for electrical wire connectors, covering scope, performance requirements, and compliance.
Scope and Application
CAN CSA C22.2 No. 65-18 is the National Standard of Canada for wire connectors, developed under the Canadian Electrical Code Part II (CSA C22.2 series). It establishes safety and performance requirements for splicing and terminating connectors intended for use with copper and aluminum conductors in electrical installations operating at up to 600 V (or 1000 V for certain applications) and with current ratings up to 200 A, as specified by the manufacturer.
The standard covers a wide range of connector types, including pressure connectors (screw-on, set-screw, and crimp-type), insulation piercing connectors, push-in connectors, and mechanical connectors. Devices covered by this standard are designed for indoor and outdoor use in dry, damp, or wet locations as marked.
Excluded from the scope are connectors for data/telecommunications circuits, connectors for use in hazardous locations, and connectors covered by other CSA standards (e.g., automotive or mining applications).
Technical Requirements
Construction and Materials
Connectors must be constructed from materials that provide adequate electrical conductivity, mechanical strength, and corrosion resistance. Metallic parts are typically copper alloy, aluminum alloy, or steel (with appropriate plating). Non-metallic components must be molded from insulating materials rated for the expected continuous operating temperature (minimum 60 °C, but often 75 °C or 90 °C). For aluminum connectors, the standard mandates the use of materials that resist galvanic corrosion and stress relaxation, with markings to indicate the compatible conductor material combinations (e.g., AL9CU for use with both aluminum and copper conductors).
Performance Criteria
All connectors are subjected to a series of type tests to verify electrical and mechanical integrity. Table 1 summarizes the key performance tests and acceptance criteria.
| Test | Requirement | Test Conditions |
|---|---|---|
| Pull-out (axial) force | Minimum 60% of the conductor breaking strength | Applied after 500 current cycles; 1-minute hold |
| Temperature rise | ΔT ≤ 30 K above ambient | Rated current applied for 4 hours |
| Dielectric voltage withstand | 1000 V + 2× rated voltage, 60 Hz, no breakdown | Applied for 1 minute between live parts and enclosure |
| Current cycling (aging) | Stable contact resistance (change < 5 mΩ typical) | 500 cycles: 1 hour on / 1 hour off |
| Corrosion resistance | No excessive corrosion or loss of function | 96-hour salt spray (copper) or 20-cycle humidity (aluminum) |
| Short-circuit (optional) | No blow-off or welding | Prospective fault current as declared by manufacturer |
Additionally, connectors must maintain low initial contact resistance. The increase in resistance after thermal cycling must not exceed the limit specified in the standard.
Temperature Ratings and Ampacity
Connectors are assigned a temperature rating—60 °C, 75 °C, or 90 °C—based on the maximum conductor insulation temperature for which they are suitable. This rating must be marked on the product or its smallest package. When implementing connectors in a circuit, the connector temperature rating must be at least equal to that of the conductor insulation to avoid de-rating the ampacity of the system. The standard also defines the procedure for establishing the connector’s current-carrying capacity in free air or when enclosed.
Implementation and Testing
Tip: Always consult the manufacturer’s installation instructions for torque values, wire strip length, and permissible conductor combinations. Using incorrect torque can lead to high resistance and overheating.
Manufacturers seeking certification must present representative samples of each connector family for type testing by an accredited laboratory (e.g., CSA, UL, or Intertek). The test plan typically includes:
- Selection of each wire size within the connector’s range (minimum, intermediate, and maximum).
- Testing with both copper (solid and stranded) and aluminum conductors when the connector is marked for both (e.g., AL9CU).
- Preconditioning of aluminum conductors (e.g., wire brushing and application of oxide inhibitor) per manufacturer recommendations.
- Execution of the test sequence: initial contact resistance → pull-out → cyclic current → temperature rise → dielectric test.
Acceptance is based on no electrical failure, no mechanical separation, and contact resistance within limits. The number of samples required per test is typically five, with zero defects allowed for the major tests.
Success: Connectors certified to CAN CSA C22.2 No. 65-18 deliver reliable service life and meet the safety requirements of the Canadian Electrical Code, Part I (CSA C22.1). Look for the certification mark on the product.
Compliance and Marking
Product Marking
Each connector (or its smallest package) must be marked with:
- Manufacturer’s name or trademark and catalog number.
- Wire range (e.g., 14 AWG – 2 AWG).
- Temperature rating: 60 °C, 75 °C, or 90 °C.
- Indication of suitability for copper (Cu), aluminum (Al), or both (e.g., AL7CU, AL9CU).
- For push-in connectors, the number and types of wires allowed (e.g., 2 × 14 AWG solid).
- Optional: Short-circuit current rating (SCCR) if tested.
Warning: Aluminum conductors require connectors specifically marked for such use. Using a connector not listed for aluminum can result in accelerated corrosion, creep relaxation, and fire hazard. Always verify the marking for AL compatibility.
Relation to the Canadian Electrical Code and Harmonization
The standard is referenced in Section 12 (Wiring Methods) of the Canadian Electrical Code, Part I. Connectors that comply with No. 65-18 are deemed acceptable for use in Canada. Moreover, CAN CSA C22.2 No. 65-18 is harmonized with UL 486C (Wire Connectors), allowing manufacturers to obtain dual certification for the North American market. Differences between the two documents are minimal and pertain primarily to regulatory language and specific test details.
Danger: Installation of wire connectors without proper training can lead to arc faults, overheating, and electrical fires. All connections must be installed by qualified electricians in accordance with the manufacturer’s instructions and the governing electrical code.
Frequently Asked Questions
Q: What types of wire connectors are covered by CAN CSA C22.2 No. 65-18?
A: The standard covers pressure connectors (screw, set-screw, crimp), insulation piercing connectors, push-in connectors, and other splicing and terminating devices for copper and aluminum conductors rated up to 600 V (or 1000 V) and up to 200 A inclusive. Connectors for hazardous locations or low voltage signaling are not included.
A: The standard covers pressure connectors (screw, set-screw, crimp), insulation piercing connectors, push-in connectors, and other splicing and terminating devices for copper and aluminum conductors rated up to 600 V (or 1000 V) and up to 200 A inclusive. Connectors for hazardous locations or low voltage signaling are not included.
Q: What are the key performance tests required for certification?
A: Key tests include the pull-out force test (60% of conductor breaking strength), temperature rise test (ΔT ≤ 30 K), dielectric withstand test (1000 V + 2× rated voltage), current cycling (500 cycles), and corrosion resistance tests. The standard ensures electrical and mechanical reliability under normal service conditions.
A: Key tests include the pull-out force test (60% of conductor breaking strength), temperature rise test (ΔT ≤ 30 K), dielectric withstand test (1000 V + 2× rated voltage), current cycling (500 cycles), and corrosion resistance tests. The standard ensures electrical and mechanical reliability under normal service conditions.
Q: How do I know if a connector is suitable for aluminum conductors?
A: Look for a marking such as AL7CU, AL8CU, AL9CU, or AL10CU on the connector or package. These markings indicate the specific combinations of conductor materials (e.g., AL9CU means it is suitable for both aluminum and copper conductors). Only connectors marked for aluminum should be used with aluminum cables.
A: Look for a marking such as AL7CU, AL8CU, AL9CU, or AL10CU on the connector or package. These markings indicate the specific combinations of conductor materials (e.g., AL9CU means it is suitable for both aluminum and copper conductors). Only connectors marked for aluminum should be used with aluminum cables.
Q: Is CAN CSA C22.2 No. 65-18 harmonized with any US standard?
A: Yes, it is harmonized with UL 486C (Wire Connectors). While the test requirements are essentially equivalent, minor differences in marking language and some specific test conditions may exist. Dual-certification marks (e.g., cUL) are common for products destined for both markets.
A: Yes, it is harmonized with UL 486C (Wire Connectors). While the test requirements are essentially equivalent, minor differences in marking language and some specific test conditions may exist. Dual-certification marks (e.g., cUL) are common for products destined for both markets.
This article provides technical guidance for informational purposes. Always refer to the official standard for complete requirements. Published 2026.