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Understanding CSA C747-09 (2016): Energy Efficiency Testing and Compliance for Electric Motors
A comprehensive guide to the scope, technical requirements, and compliance considerations for CSA C747-09 (2016)
CSA C747-09 (2016) is a Canadian Standards Association standard that specifies test methods for determining the energy efficiency of electric motors. It is widely referenced in Canadian energy efficiency regulations and serves as the primary test protocol for demonstrating compliance with federal efficiency mandates. This article explores the scope, technical requirements, implementation highlights, and compliance notes for engineers, manufacturers, and test laboratories working with this standard.
Scope and Applicability
CSA C747-09 (2016) applies to the laboratory testing of electric motors for the purpose of determining their energy efficiency. The standard covers a broad range of motor types and ratings, including:
- Three-phase induction motors (squirrel-cage and wound rotor)
- Single-phase induction motors
- DC motors (series, shunt, compound, permanent magnet)
- Synchronous motors
The standard is applicable to motors with a rated voltage up to 1000 V and output power from 0.75 kW (1 hp) to 375 kW (500 hp). It includes both general-purpose and definite-purpose motors, though certain specialty motors (e.g., submersible motors, torque motors) may require adaptations to the test methods.
Note: CSA C747-09 (2016) was reaffirmed in 2016 without technical changes from the 2009 edition. Users should verify that the most current version is referenced in applicable regulations.
Technical Requirements
Test Methods
The standard defines four primary test methods for efficiency determination:
| Method | Description | Typical Application |
|---|---|---|
| Input-Output (Direct) | Direct measurement of electrical input power and mechanical output power using a dynamometer or torque transducer. | Small motors (≤ 10 kW), where high accuracy torque measurement is feasible. |
| Loss Segregation | Measurement of individual losses (stator I²R, rotor I²R, core, friction & windage, stray load) and summation to obtain efficiency. | Medium to large motors (10–375 kW), where direct torque measurement is impractical. |
| Eh Star Method | An alternative loss segregation method using a no-load test and two load points. | Induction motors where full-load testing is constrained (e.g., high inertia loads). |
| Equivalent Circuit Method | Determination of motor parameters from no-load and locked-rotor tests, efficiency calculated from a per-phase equivalent circuit. | Small motors and quality control testing. |
Instrumentation and Accuracy
CSA C747-09 (2016) imposes strict requirements on test instrumentation to ensure traceability and repeatability:
- Power analyzers must have accuracy better than ±0.5% of reading for voltage and current.
- Torque transducers must be calibrated within ±0.2% of full scale.
- Speed measurement requires an encoder or stroboscope with ±0.1% accuracy.
- All instruments must be calibrated within the preceding 12 months per ISO/IEC 17025.
Temperature Correction
Efficiency results are corrected to a reference ambient temperature of 25 °C using standardized winding resistance correction factors. The standard specifies procedures for measuring winding temperature at the end of the test and applying the correction formula:
ηref = ηtest × (Rref / Rhot)0.5 for losses
Tip: For accurate temperature measurement, embed thermocouples in the stator windings or use the resistance method immediately after shutdown.
Implementation Highlights
When implementing CSA C747-09 (2016) in a test lab or manufacturing quality system, consider the following:
Test Setup
The motor must be mounted on a rigid base with the shaft aligned to the dynamometer or load machine within 0.05 mm. The test environment must be draft-free, with ambient temperature maintained at 25 ± 5 °C. A pre-run stabilizing period of at least 1 hour at rated load is required before conducting efficiency tests.
Stray Load Loss Determination
For the loss segregation method, stray load loss is determined via the “Reverse Rotation Test” or the “Eh Star Method” as per the standard. The acceptable stray loss is limited to a maximum of 0.5% of input power for motors below 90 kW, and 0.2% for larger motors, unless explicitly measured.
Warning: Stray load loss is a major source of uncertainty. Use the Eh Star method for improved repeatability when testing induction motors above 100 kW.
Reporting
The standard requires a detailed test report including:
- Motor nameplate data and manufacturer
- Test method used and any deviations
- Measured and corrected efficiency values at 25%, 50%, 75%, 100%, and 125% load (where applicable)
- Uncertainty analysis per ISO Guide 98-3 (GUM)
Compliance Notes
CSA C747-09 (2016) is a normative reference in the Canadian Energy Efficiency Regulations (SOR/94-651) for electric motors. Compliance with these regulations requires that motors supplied in Canada meet minimum efficiency levels (e.g., IE3/High Efficiency) and that the efficiency is verified using the test methods of CSA C747 or an equivalent standard (such as IEC 60034-2-1) when recognized by the Minister.
Relation to Other Standards
The table below compares CSA C747-09 (2016) with other major motor efficiency test standards:
| Standard | Region | Key Differences from CSA C747 |
|---|---|---|
| IEC 60034-2-1 (2014) | International / Europe | Uses loss segregation as primary method; different stray-load loss determination. CSA C747 allows a wider range of methods. |
| IEEE 112-B | USA | Very similar to CSA C747; CSA C747 is harmonized with IEEE 112-B for three-phase motors. |
| NEMA MG 1-2018 | USA | References IEEE 112 methods; provides efficiency classes but not detailed test procedures. |
| AS/NZS 1359.102.3 | Australia / NZ | Essentially identical to IEC 60034-2-1. Not directly harmonized with CSA C747. |
Compliance Tip: For motors sold in Canada, the efficiency values declared must be the lowest expected value (LEV) based on a statistical analysis of production test results. CSA C747 provides guidance for establishing the LEV.
Important: Failure to use a recognized test method or inaccurate efficiency declarations can lead to penalties under the Energy Efficiency Act. The standard should be used in conjunction with CSA C390 (energy efficiency performance requirements).
Laboratory Accreditation
Tests performed for regulatory compliance must be conducted by a laboratory accredited to ISO/IEC 17025 for the specific test methods of CSA C747-09 (2016). The accreditation body must be a signatory to the International Laboratory Accreditation Cooperation (ILAC) Mutual Recognition Arrangement.
Frequently Asked Questions
Q: Is CSA C747-09 (2016) mandatory in Canada?
A: The standard itself is voluntary, but it is referenced by the Energy Efficiency Regulations as the official test method for electric motor efficiency. Therefore, any motor that must meet minimum efficiency levels must be tested according to CSA C747 or an equivalent recognized method to demonstrate compliance.
A: The standard itself is voluntary, but it is referenced by the Energy Efficiency Regulations as the official test method for electric motor efficiency. Therefore, any motor that must meet minimum efficiency levels must be tested according to CSA C747 or an equivalent recognized method to demonstrate compliance.
Q: How does CSA C747-09 differ from IEC 60034-2-1?
A: While both standards use loss segregation methods, CSA C747-09 (2016) offers more flexibility by allowing direct input-output testing for small motors and the Eh Star method for stray loss. The uncertainty evaluation and reporting requirements are also more prescriptive in the Canadian standard.
A: While both standards use loss segregation methods, CSA C747-09 (2016) offers more flexibility by allowing direct input-output testing for small motors and the Eh Star method for stray loss. The uncertainty evaluation and reporting requirements are also more prescriptive in the Canadian standard.
Q: Can I use IEEE 112-B instead of CSA C747?
A: Yes, IEEE 112-B is recognized as equivalent for three-phase induction motors under the Canadian regulations. However, single-phase motors and DC motors must be tested using CSA C747 methods.
A: Yes, IEEE 112-B is recognized as equivalent for three-phase induction motors under the Canadian regulations. However, single-phase motors and DC motors must be tested using CSA C747 methods.
Q: What are the key changes in the 2016 reaffirmation?
A: The 2016 edition reaffirmed the 2009 content without technical amendments. The standard remains current until the next revision cycle. Laboratories should check for any addenda or corrigenda that may have been issued.
A: The 2016 edition reaffirmed the 2009 content without technical amendments. The standard remains current until the next revision cycle. Laboratories should check for any addenda or corrigenda that may have been issued.
© 2026 – This article is provided for informational purposes and does not constitute legal or professional advice. Always refer to the official standard for complete requirements.