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CSA C22.2 No. 60691-19: Thermal-Links in Canada – Requirements and Compliance Guide
Understanding the Canadian adoption of IEC 60691 for thermal cut‑off devices
Scope and Application
CSA C22.2 No. 60691‑19 is the Canadian national adoption of IEC 60691:2015 (Edition 4.0) with prescribed Canadian deviations. This standard applies to thermal‑links (also called thermal cut‑offs or temperature fuses) intended for incorporation in electrical appliances, equipment, and components as a protection device against abnormal overheating. Thermal‑links covered by this standard are non‑resettable devices that open the circuit when its sensing temperature reaches a predetermined value.
The document addresses devices with rated voltages up to 250 V a.c., rated currents up to 100 A, and rated temperature (Tf) usually between 50 °C and 300 °C. It includes both organic and inorganic thermal‑link technologies and provides requirements for construction, performance, testing, and marking. The standard is referenced by the Canadian Electrical Code, Part I (CSA C22.1) for the approval of thermal‑links used in equipment installed in Canada.
Tip: While the international edition (IEC 60691) is used globally, any thermal‑link sold in Canada must meet the specific Canadian deviations included in CSA C22.2 No. 60691‑19. Product certification to the national version is mandatory.
Technical Requirements
Construction and Materials
Thermal‑links must be constructed with materials that ensure stable operation over the expected service life. Key construction requirements include:
- Use of creepage and clearance distances consistent with the rated voltage (based on CSA C22.2 No. 0 or pollution degree 2).
- Encapsulation material must not degrade or become brittle at the rated temperature.
- Terminals shall be designed for the connection method (solder, crimp, or welded) and must withstand the specified pull and torque tests.
- Devices with organic sensing elements require a protective cover or sleeving when used in applications where exposed to conductive contaminants.
- All components must comply with the material flammability requirements of the Canadian Electrical Code.
Performance and Testing
The standard defines a series of type tests to verify the thermal‑link’s ability to operate safely under normal and abnormal conditions. The major tests and their acceptance criteria are summarised in the table below.
| Test Item | Conditions / Procedure | Acceptance Criteria |
|---|---|---|
| Rated temperature (Tf) verification | Heating in a temperature‑controlled oven; rate of rise ≤ 1 °C/min | Opening temperature within ± 5 °C (or ± 2 % of Tf, whichever is greater) of declared Tf |
| Holding temperature (Th) | Device held at Th = Tf – 20 °C (or – 15 °C for Tf ≤ 100 °C) for 168 h | No change in continuity; resistance drift ≤ 10 % |
| Endurance at rated current | 1.25 × Irated applied at room temperature for 100 h | No opening, no visible damage, insulation resistance ≥ 5 MΩ |
| Dielectric voltage withstand | 1 500 V a.c. (rms) between terminals and case, and across open gap (after operation) | No flashover or breakdown; leakage current ≤ 1 mA |
| Short‑circuit capability (when applicable) | Prospective current 500 A (or 3 × Irated, whichever is higher) at rated voltage | Fuse element must clear the fault without rupture of enclosure |
| Environmental conditioning | Damp heat (40 °C, 93 % RH, 21 days) and thermal cycling (– 10 °C to Tf, 5 cycles) | No degradation, Tf shift ≤ 5 °C |
Warning: The dielectric test voltage for Canadian certification is 1 500 V a.c., which is higher than the 1 250 V a.c. required by IEC 60691. This is a critical deviation that must be accounted for in design.
Implementation Highlights
When integrating a thermal‑link into an end‑product, engineers should note the following practical aspects derived from CSA C22.2 No. 60691‑19:
- Wire lead colors: For devices intended for Canada, the standard allows lead colors as per the wiring code (e.g., black for hot, white for neutral, green for ground) when the thermal‑link is rated for direct connection. Deviant colors must be clearly marked.
- Orientation and mounting: The thermal‑link must be mounted in close thermal contact with the component to be protected. If the device is designed to sense air temperature, free air access is required.
- Soldering considerations: Heat from soldering or welding during assembly must not cause a shift in the rated opening temperature. The standard requires a “dry‑heat” test at Tf – 10 °C for 30 s to simulate soldering stress.
- Electrical rating markings: Markings on the device or packaging must include Tf, rated voltage, and rated current. If the device is not marked, the product documentation must include this information.
Best Practice: Always consult the latest edition of CSA C22.2 No. 0 (General Requirements) and the applicable end‑product standard to ensure complete compliance. Thermal‑links are considered critical safety components and should be certified by an accredited body (CSA, UL, Intertek, etc.).
Compliance Notes and Certification
To obtain product certification to CSA C22.2 No. 60691‑19, manufacturers must submit samples to a recognized certification organization. The certification process includes:
- Review of construction and material data.
- Witness of all type tests listed in the standard.
- Verification of Canadian deviations (e.g., dielectric voltage, marking language, and wire compatibility).
- Follow‑up factory inspections covering production line testing and traceability.
It is important to note that a thermal‑link certified only to IEC 60691 is not automatically accepted under the Canadian Electrical Code. The CSA national deviations impose additional safety margins, particularly in dielectric strength and endurance testing, that reflect the requirements of the Canadian installation environment. Therefore, component certification must explicitly reference CSA C22.2 No. 60691‑19.
Important: Using a non‑certified thermal‑link in a product sold in Canada violates provincial electrical codes and can lead to recall, liability issues, and loss of safety marks. Always verify that the device carries a valid CSA, cUL, or cETL mark indicating compliance with CSA C22.2 No. 60691‑19.
Frequently Asked Questions (FAQs)
Q: What are the main differences between IEC 60691 and CSA C22.2 No. 60691‑19?
A: The Canadian version includes stricter dielectric withstand (1 500 V vs. 1 250 V), additional requirements for wire colours and terminal sizes, mandatory shielding for organic sensing elements, and specific marking language requirements (English/French). It also references the Canadian Electrical Code for installation conditions.
A: The Canadian version includes stricter dielectric withstand (1 500 V vs. 1 250 V), additional requirements for wire colours and terminal sizes, mandatory shielding for organic sensing elements, and specific marking language requirements (English/French). It also references the Canadian Electrical Code for installation conditions.
Q: Can a thermal‑link be reused after it has opened?
A: No. Thermal‑links covered by this standard are single‑use, non‑resettable devices. Once the element melts or breaks, the device must be replaced. Any attempt to reset or bypass it would violate safety requirements.
A: No. Thermal‑links covered by this standard are single‑use, non‑resettable devices. Once the element melts or breaks, the device must be replaced. Any attempt to reset or bypass it would violate safety requirements.
Q: What documentation is required for certification?
A: The manufacturer must provide rated temperature (Tf), holding temperature (Th), rated voltage/current, dimensional drawings, material specifications (including flammability data), and a detailed description of the production test programme. The certification body will also request test results or witness testing.
A: The manufacturer must provide rated temperature (Tf), holding temperature (Th), rated voltage/current, dimensional drawings, material specifications (including flammability data), and a detailed description of the production test programme. The certification body will also request test results or witness testing.
Q: Is there a maximum rated temperature limitation?
A: The standard does not impose an absolute maximum, but practical limits arise from material constraints and application. For temperatures above 300 °C, alternative protective devices (e.g., thermal fuses with ceramic bodies) may be required, and additional tests for high‑temperature stability are recommended.
A: The standard does not impose an absolute maximum, but practical limits arise from material constraints and application. For temperatures above 300 °C, alternative protective devices (e.g., thermal fuses with ceramic bodies) may be required, and additional tests for high‑temperature stability are recommended.
© 2026 Technical Article – CSA C22.2 No. 60691‑19. Content provided for informational purposes and does not replace the official standard.