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CAN CSA C22.2 No. 60950-21-03 (2016): Safety of Remote Power Feeding for Information Technology Equipment
A Comprehensive Guide to the Canadian Standard for Remote Power Feeding Circuits in IT and Telecommunications Devices
CAN/CSA C22.2 No. 60950-21-03 (2016) is the Canadian adoption of IEC 60950-21:2002, with Canadian modifications as required by the Canadian Electrical Code, Part II. This standard specifies safety requirements for remote power feeding (RPF) circuits used in information technology equipment (ITE), including telecommunications network equipment. It covers both the source and the receiving sides of RPF systems, such as Power over Ethernet (PoE) switches, powered devices (PDs), and other equipment that delivers or receives power over communication cables. Compliance with this standard is essential for manufacturers seeking to sell ITE in Canada, as it ensures protection against electric shock, fire, and mechanical hazards arising from the use of RPF circuits.
Scope and Applicability
The scope of CSA C22.2 No. 60950-21-03 covers RPF circuits intended to supply power to equipment connected via telecommunication networks or dedicated cabling systems. It applies to:
- Equipment that provides or consumes remote power over twisted-pair copper cables (e.g., Ethernet, DSL, or proprietary interfaces).
- RPF circuits operating at direct voltages up to 400 V DC under normal operating conditions.
- Circuits classified as SELV, TNV, or specifically as RPF circuits depending on voltage and current limits.
- Both indoor and outdoor applications when the connected equipment is within the same building or campus.
The standard does not apply to power feeding over coaxial cables or fiber optic cables, nor to RPF circuits that are part of centralized power systems supplying entire buildings. It is intended to be used together with CAN/CSA C22.2 No. 60950-1 (the base standard for ITE safety) or, in a transitional context, with CAN/CSA C22.2 No. 62368-1 (Audio/Video, Information and Communication Technology Equipment).
Tip: When designing a PoE sourcing equipment (PSE) for the Canadian market, consider both this standard and the relevant IEEE 802.3 specifications. CSA C22.2 No. 60950-21-03 provides the safety framework, while IEEE 802.3 defines the electrical parameters and interoperability.
Technical Requirements
Circuit Classification and Limits
The standard defines several circuit types based on voltage, current, and power limitations. For RPF circuits, specific limits are imposed to reduce the risk of electric shock and fire. The table below summarizes the key classification limits.
| Circuit Type | Maximum Voltage (V DC) | Maximum Current (A) | Maximum Power (VA) | Insulation from Mains |
|---|---|---|---|---|
| SELV | ≤ 60 | No limit (but limited power source required) | Not defined (LPS limited to 100 VA) | Reinforced or double |
| TNV-1 | ≤ 60 | No limit | Not defined | Basic (supplementary if accessible) |
| TNV-2 | ≤ 120 (or >60 without overvoltage protection) | No limit | Not defined | Basic |
| TNV-3 | ≤ 120 (subject to network overvoltages) | No limit | Not defined | Reinforced or double |
| RPF Circuit | ≤ 400 | ≤ 0.15 (for V > 60) or LPS compliant | ≤ 100 | Basic or reinforced (depending on accessibility) |
Note: RPF circuits must either be inherently limited in power (e.g., through a limited power source circuit) or be protected by an overcurrent protective device that opens the circuit under fault conditions. The limits above are for steady-state operation; transient overvoltages are also considered.
Insulation and Dielectric Strength
The standard requires that RPF circuits be separated from hazardous voltage circuits (such as mains) by at least basic insulation, and from accessible conductive parts by double or reinforced insulation unless the circuit is fully within SELV limits. Dielectric strength tests are performed at 1500 V AC (or 2121 V DC) for basic insulation and 3000 V AC (or 4242 V DC) for reinforced insulation, depending on the working voltage. Additional requirements apply for creepage and clearance distances based on the nominal voltage of the RPF circuit.
Warning: RPF circuits with voltages above 60 V DC are not considered SELV. Ensure that connectors are polarized or shaped to prevent inadvertent contact with hazardous voltages. Use touch-safe connectors and clearly label circuit types in the equipment.
Overcurrent and Short-Circuit Protection
The RPF source must be designed to limit the output current under abnormal conditions (e.g., short circuit on the cable). This is typically achieved by using a current-limiting integrated circuit or a fuse/PTC. The standard specifies that the limited power source (LPS) requirements of IEC 60950-1 are applied, which limit the available current to 8 A sine wave equivalent for voltages above 30 V RMS. For DC voltages above 60 V, the current limit is more stringent—usually not exceeding 150 mA.
Implementation and Testing Highlights
To demonstrate compliance with CAN/CSA C22.2 No. 60950-21-03, manufacturers must perform a series of engineering analyses and tests. Key steps include:
- Circuit classification – Determining the circuit type (SELV, TNV, or RPF) based on its voltage, current, and power characteristics.
- Isolation analysis – Verifying that distances through insulation (creepage, clearance, and solid insulation) meet the minimum values for the working voltage and insulation grade.
- Dielectric strength testing – Performing hipot tests on insulation barriers between RPF circuits and other parts.
- Current and power limitation tests – Measuring the output current under worst‑case overload and short‑circuit conditions to confirm it stays within allowed limits.
- Fault condition testing – Simulating component failures (e.g., a shorted FET in the power supply) to ensure that the equipment does not become dangerous.
Best Practice: Incorporating a dedicated limited power source (LPS) test during development can accelerate certification. Many foundries now provide power management ICs with built-in LPS capability that simplify compliance to this standard.
Compliance and Certification Notes
In Canada, compliance with the applicable CSA C22.2 standards is generally mandatory under provincial electrical codes and regulations. For ITE incorporating RPF, product certification to CSA C22.2 No. 60950-21-03 is typically performed by an accredited certification body (e.g., CSA Group, UL, Intertek, TÜV Rheinland). The certification process includes:
- Review of product documentation, schematics, and bill of materials.
- Witness or documented testing in accordance with the standard.
- Factory inspections to ensure ongoing quality control.
- Issuance of a Certificate of Compliance and permission to use the CSA mark (or recognized national safety mark).
It is important to note that this standard is based on IEC 60950-21, which is now integrated into IEC 62368-1. However, for many existing products designed before the transition, CSA C22.2 No. 60950-21-03 remains an acceptable alternative. Manufacturers developing new products are encouraged to comply with CAN/CSA C22.2 No. 62368-1 (the Canadian adoption of IEC 62368-1), which supersedes both 60950-1 and 60950-21. Consult the certification body for the current acceptability.
Marking requirements: The standard mandates that the equipment nameplate include the electrical ratings of the RPF output (voltage, current, power) and if the circuit is LPS. Additionally, connectors for RPF circuits must be clearly identified with the symbol for functional earth (if applicable) or with the text “RPF”.
Frequently Asked Questions
Q: What is the scope of CAN/CSA C22.2 No. 60950-21-03?
A: The standard applies to remote power feeding circuits used in information technology equipment, including PoE sources and powered devices. It covers circuit classification, insulation, and protection requirements to ensure safety against electric shock and fire hazards. It applies to RPF circuits with a maximum voltage of 400 V DC and power limited to 100 VA.
A: The standard applies to remote power feeding circuits used in information technology equipment, including PoE sources and powered devices. It covers circuit classification, insulation, and protection requirements to ensure safety against electric shock and fire hazards. It applies to RPF circuits with a maximum voltage of 400 V DC and power limited to 100 VA.
Q: What are the main differences between this Canadian standard and the international IEC 60950-21?
A: CAN/CSA C22.2 No. 60950-21-03 is based on IEC 60950-21:2002 but includes Canadian deviations. Notable differences include requirements for supply connections (grounding), ambient temperature ranges for North America, and references to the Canadian Electrical Code, Part I. The general safety objectives remain the same.
A: CAN/CSA C22.2 No. 60950-21-03 is based on IEC 60950-21:2002 but includes Canadian deviations. Notable differences include requirements for supply connections (grounding), ambient temperature ranges for North America, and references to the Canadian Electrical Code, Part I. The general safety objectives remain the same.
Q: How does this standard apply to modern Power over Ethernet (PoE) equipment?
A: PoE equipment typically falls within the scope of this standard because it transmits power over twisted-pair cables. The standard sets limits on voltage, current, and power for RPF circuits. For typical IEEE 802.3af/at/bt systems (≤ 56 V DC, up to 90 W), the circuit must be LPS compliant. The standard also dictates isolation requirements between the PoE circuit and the mains power supply.
A: PoE equipment typically falls within the scope of this standard because it transmits power over twisted-pair cables. The standard sets limits on voltage, current, and power for RPF circuits. For typical IEEE 802.3af/at/bt systems (≤ 56 V DC, up to 90 W), the circuit must be LPS compliant. The standard also dictates isolation requirements between the PoE circuit and the mains power supply.
Q: Is this standard still relevant after the adoption of IEC 62368-1?
A: Yes. While IEC 62368-1 (and its Canadian adoption) now covers the safety of ITE and a/v equipment, CAN/CSA C22.2 No. 60950-21-03 may still be used for legacy certifications and as a reference for equipment that is already designed to the 60950 series. For new products, manufacturers should check with their certification body to determine whether compliance with 62368-1 can also satisfy the RPF requirements or if separate evaluation to 60950-21-03 is required.
A: Yes. While IEC 62368-1 (and its Canadian adoption) now covers the safety of ITE and a/v equipment, CAN/CSA C22.2 No. 60950-21-03 may still be used for legacy certifications and as a reference for equipment that is already designed to the 60950 series. For new products, manufacturers should check with their certification body to determine whether compliance with 62368-1 can also satisfy the RPF requirements or if separate evaluation to 60950-21-03 is required.
Technical Article — Updated 2026