Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
CAN CSA C872-14 (2015): Technical Requirements for Grid-Connected Photovoltaic Inverters
An in-depth analysis of the Canadian standard for utility-interactive PV inverter safety, performance, and testing
Introduction
CAN CSA C872-14 (2015) is a Canadian national standard developed by the Canadian Standards Association (CSA) that specifies safety and performance requirements for photovoltaic (PV) inverters intended for utility-interactive (grid-connected) systems. It is the reference document for manufacturers, installers, and testing laboratories evaluating the suitability of PV inverters for interconnection with low-voltage distribution networks in Canada. The standard aligns closely with North American harmonization efforts and incorporates specific Canadian deviations from UL 1741, ensuring that inverters meet the unique requirements of the Canadian Electrical Code (CSA C22.1) and utility grid codes.
Scope and Application
The standard applies to self-commutated inverters that are designed to convert direct current (DC) energy from photovoltaic arrays into alternating current (AC) power for injection into an electric power system.
Covered Inverter Types
CAN CSA C872-14 (2015) covers:
- Single-phase and three-phase utility-interactive inverters
- Inverters with a maximum system voltage up to 1 000 V DC (nominal) and AC voltage up to 600 V (phase-to-phase)
- Inverters intended for indoor or outdoor installation (enclosure ratings NEMA 3R, 4, 4X, etc.)
- Microinverters and string inverters (with or without integrated DC-to-DC converters)
Exclusions
The standard does not cover stand-alone (off-grid) inverters, battery charge controllers, DC-to-DC converters used solely for battery charging, or electrical energy storage equipment (those fall under other CSA standards such as CSA C22.2 No. 107.1 or CSA C872.1).
Tip: When evaluating an inverter for CSA C872 compliance, confirm that the product’s intended application is strictly utility-interactive. Hybrid units with stand-alone capability must also meet additional requirements of CSA C22.2 No. 107.1.
Technical Requirements
CAN CSA C872-14 (2015) is divided into two major domains: safety and performance. The requirements below summarize the critical parameters that a compliant inverter must satisfy.
Electrical Safety
- Ground Fault Detection and Interruption: The inverter must detect a DC ground fault and either interrupt the fault current or signal an alarm. For inverters with transformerless topologies, additional DC injection monitoring is required.
- Anti-Islanding Protection: When the utility grid is de-energized, the inverter shall cease to energize the grid within two seconds (2 s). Testing is performed at multiple power levels and quality factor conditions.
- Isolation and Withstand Voltage: Dielectric voltage withstand tests at twice the rated voltage plus 1 000 V AC (or appropriate DC equivalent) with no breakdown.
- Leakage Current: Under normal operating conditions, the ground leakage current shall not exceed 10 mA for inverters with exposed metallic enclosures.
- Surge Withstand: The inverter must withstand voltage surges of up to 6 kV (open circuit) and 3 kA (short circuit) as defined in IEEE C62.41.
Power Quality and Grid Support
Performance requirements are harmonized with IEEE 1547 and CSA C22.3 No. 9, with Canadian-specific amendments:
- Harmonic Distortion: Total current harmonic distortion (THD) less than 5% of rated current, with individual odd harmonics limited per Table 1.
- Power Factor: For inverters above 10 kVA, the power factor must be ≥ 0.9 (leading or lagging) when output is greater than 10% of rated power.
- Voltage and Frequency Ride-Through: The inverter must stay connected during voltage deviations from 88% to 110% of nominal (nominal voltage) for up to 2 seconds, and frequency deviations of 59.3 Hz to 60.5 Hz for continuous operation.
- DC Current Injection: Less than 0.5% of the rated AC current.
| Requirement | Parameter | Test Condition | Limit / Criterion |
|---|---|---|---|
| THD (total harmonic distortion) | Current harmonics | 100% rated power, balanced grid | < 5% (THD); individual odd < 4% (h<11), < 2% (11≤h<17), < 1.5% (17≤h<23), < 0.6% (23≤h<35), < 0.3% (h≥35) |
| Anti-Islanding | Islanding detection time | Grid disconnection, ±1% frequency shift | < 2 s |
| DC Injection | DC current component | Any output power level | < 0.5% of rated AC current |
| Ground Fault Detection | Fault current threshold | Single fault to ground on DC side | Detection within 1 s; interruption or alarm |
| Voltage Ride-Through | Under/over voltage | 88%–110% of nominal for 2 s | Inverter remains connected; trips beyond limits based on curve |
Environmental and Mechanical
- Ambient Temperature Range: -25°C to +50°C (indoor) or -40°C to +50°C (outdoor) depending on enclosure rating.
- Enclosure Integrity: Inverters must pass rain, dust, and ice tests as per CSA C22.2 No. 94.2.
- Thermal Cycling: 100 cycles from low to high temperature at maximum rated power with no degradation.
- Vibration: Random vibration per IEC 60068-2-64 (transport and operational).
Implementation and Compliance
Path to Certification
Manufacturers seeking CSA certification for their inverters must:
- Submit a complete product description, schematics, and bill of materials.
- Perform type testing at a CSA-recognized laboratory (e.g., CSA Group, Intertek, UL).
- Undergo factory inspection and initial production testing.
- Obtain the CSA Mark for utility-interactive inverters (component recognition or full listing).
Compliance milestone: Once the inverter receives the CSA listing mark, it is accepted by most Canadian electrical inspectors and utilities without additional testing, provided the installation follows CSA C22.1 (CEC) Part I requirements.
Differences from UL 1741 (2021)
Although CAN CSA C872-14 (2015) is harmonized with UL 1741, the following Canadian-specific variations exist:
- Stringent requirements for AC ground fault protection (mandatory for all inverters, regardless of transformer type).
- Additional dielectric withstand test for PV input circuits.
- Markings must be bilingual (English/French) and include the “CSA” mark.
- Compliance with Canadian Grid Interconnection requirements (CSA C22.3 No. 9 / IEEE 1547 with provincial utility amendments).
Important: Inverters certified only to UL 1741 without Canadian deviations may not satisfy the requirements of CAN CSA C872-14. Always verify that the product carries a valid CSA C872 marking for Canadian installations.
Compliance Notes and Best Practices
Common Pitfalls During Testing
- Anti-Islanding: Inverters with fast MPPT algorithms can exhibit irregular islanding detection times. It is recommended to test at 25%, 50%, and 100% of rated power under quality factor (Q) = 2.5 conditions.
- Ground Fault Detection: Ensure that the residual current monitoring device (RCD) is not so sensitive that it trips during normal capacitance-to-ground charging currents.
- DC Injection: Transformerless topologies must include dedicated DC current sensing and shutdown circuitry.
Installation Considerations
- The inverter must be permanently marked with its CSA file number and model.
- Utility interconnection agreements often require that the inverter is listed to CSA C872-14.
- Periodic recalibration of internal sensors (current, voltage) is recommended every 5 years to maintain power quality compliance.
Hazard: Failure to comply with the anti-islanding requirement can result in severe safety hazards for utility workers and damage to the grid. Never bypass or modify the internal islanding detection circuit.
Frequently Asked Questions
Q: Does CAN CSA C872-14 (2015) apply to inverters used in battery energy storage systems?
A: Not directly. The standard is intended for PV-only utility-interactive inverters. If the inverter also supports battery charging or standalone operation, it must also comply with other CSA standards such as CSA C22.2 No. 107.1 (for battery chargers) and CSA C872.1 (for hybrid multimode inverters). Some combined tests are recognized.
A: Not directly. The standard is intended for PV-only utility-interactive inverters. If the inverter also supports battery charging or standalone operation, it must also comply with other CSA standards such as CSA C22.2 No. 107.1 (for battery chargers) and CSA C872.1 (for hybrid multimode inverters). Some combined tests are recognized.
Q: Is CSA C872-14 the same as UL 1741?
A: They are harmonized in many respects, but CSA C872 contains Canadian-specific deviations including additional DC ground fault requirements, bilingual marking, and stricter testing for transformerless inverters. A UL 1741 listing alone is not sufficient for Canadian installation unless the product is also recognized under CSA C872.
A: They are harmonized in many respects, but CSA C872 contains Canadian-specific deviations including additional DC ground fault requirements, bilingual marking, and stricter testing for transformerless inverters. A UL 1741 listing alone is not sufficient for Canadian installation unless the product is also recognized under CSA C872.
Q: How often must an inverter be recertified?
A: Re-certification is required when the product design changes (e.g., major electrical or software changes). For unchanged products, the manufacturer must maintain a follow-up inspection program annually. The standard itself is reaffirmed periodically; currently, CSA C872-14 remains active until superseded by a newer edition.
A: Re-certification is required when the product design changes (e.g., major electrical or software changes). For unchanged products, the manufacturer must maintain a follow-up inspection program annually. The standard itself is reaffirmed periodically; currently, CSA C872-14 remains active until superseded by a newer edition.
Q: What is the maximum DC voltage allowed by the standard?
A: The standard covers inverters with a maximum system voltage of 1 000 V DC. For systems above 1 000 V DC (e.g., 1 500 V DC utility-scale inverters), additional requirements from CSA C22.2 No. 107.1 and the Canadian Electrical Code (Section 64) apply.
A: The standard covers inverters with a maximum system voltage of 1 000 V DC. For systems above 1 000 V DC (e.g., 1 500 V DC utility-scale inverters), additional requirements from CSA C22.2 No. 107.1 and the Canadian Electrical Code (Section 64) apply.
© 2026 – All rights reserved. This technical summary is provided for informational purposes and does not replace the official text of CAN CSA C872-14 (2015). For certification and legal compliance, refer to the full standard published by CSA Group.