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Scope of CAN CSA C50‑14 (2018)
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CAN CSA C50‑14 (2018) is the Canadian national adoption of IEC 60034‑14:2018, titled Rotating electrical machines – Part 14: Mechanical vibration of certain machines with shaft heights 56 mm and higher – Measurement, evaluation and limits of vibration severity. Published by the Canadian Standards Association (CSA), this standard provides accepted methods for measuring vibration at bearing housings and specifies limit values for wide categories of rotating electrical machines.
It is used by manufacturers, end‑users, and maintenance personnel to ensure that vibration levels remain within safe thresholds under steady‑state operating conditions, directly supporting reliability and safety. The standard applies equally in factory acceptance testing and on‑site acceptance verification.
Key objective: CAN CSA C50‑14 (2018) harmonises Canadian practice with international requirements while retaining national deviations tailored to local regulatory and environmental contexts.
Scope of CAN CSA C50‑14 (2018)
The standard covers rotating electrical machines with shaft heights (H) of 56 mm and above. It is applicable to:
- Induction motors, synchronous machines, DC machines, and certain types of brushless alternators.
- Mounted on rigid or flexible foundations as defined in the standard.
- Machines operating under rated steady‑state conditions (voltage, frequency, load, and temperature at the end of the test).
Exclusions: The standard does not apply to machines with reciprocating parts (e.g., piston compressors integral with the motor), machines intended for shipboard installation, or vertical machines with thrust bearings unless otherwise agreed. It also does not cover transient conditions such as startup or load changes unless specifically required by a purchase specification.
Important: Machines with special construction features (e.g., integrally geared shafts, cantilevered rotors) may require additional vibration criteria not defined in this standard.
Technical Requirements
Measurement Conditions
All vibration measurements must be taken during steady‑state operation with the machine running at rated speed, voltage, and load (or at the operating speed agreed upon by parties). The standard specifies:
- Measurement quantities: Vibration velocity (mm/s RMS) is the preferred quantity. In special cases, vibration displacement (μm peak‑to‑peak) or acceleration (m/s² peak) may be used when the dominant frequency components are below 10 Hz or above 1000 Hz.
- Measurement positions: On bearing housings in three orthogonal directions (vertical, horizontal, axial). For machines with shaft heights > 225 mm, additional positions on the housing may be required.
- Frequency range: The vibration signal is filtered to include components from 10 Hz to 1000 Hz (or up to the machine’s rotational speed harmonic order, whichever is larger).
Caution: Measurements must be taken using a properly calibrated transducer (e.g., piezoelectric accelerometer) with known sensitivity and frequency response. Incorrect mounting can lead to resonance errors of ±20 % or more.
Vibration Severity Criteria
CAN CSA C50‑14 defines maximum permissible vibration levels according to the machine’s shaft height (H) and mounting arrangement. The severity grades A, B, and C are defined in accordance with ISO 10816‑1; for the majority of standard industrial machines, Grade A applies.
The following table summarises the RMS vibration velocity limits for the most common category of machines (Grade A, shaft height 56 mm to 225 mm and above):
| Shaft Height H (mm) | Rigid Mounting (mm/s RMS) | Flexible Mounting (mm/s RMS) |
|---|---|---|
| 56 ≤ H ≤ 132 | 1.8 | 2.8 |
| 132 < H ≤ 225 | 2.8 | 4.5 |
| 225 < H ≤ 630 | 4.5 | 7.1 |
| H > 630 | 7.1 | 11.2 |
Values from CAN CSA C50‑14 (2018) Table 2 – Vibration severity limits for category 1 machines (broad adoption). Consult the actual standard for complete tables including categories 2 and 3.
Important: For machines with shaft heights above 630 mm, the standard often requires agreement between manufacturer and user, and values may be adjusted based on dynamic behaviour and bearing type.
Mounting Arrangements
The type of mounting significantly affects the measured vibration amplitude because it changes the system’s natural frequencies and damping. CAN CSA C50‑14 distinguishes between:
- Rigid mounting: The machine is attached to a massive, non‑resonant foundation (e.g., a concrete block several times heavier than the machine). Elastic mounts such as springs or pads that isolate vibration are not permitted for rigid mounting assignment.
- Flexible mounting: The machine is suspended on springs, rubber pads, or other isolating elements. The limits are relaxed by a factor of approximately 1.55 compared to rigid mounting because fully isolated machines tend to exhibit larger relative motion at the bearing housings.
Implementation Highlights
Differences from IEC 60034‑14
CAN CSA C50‑14 is technically equivalent to IEC 60034‑14:2018, but with a few national deviations required by Canadian regulations and climate conditions:
- The use of imperial units (inches, pounds) is permitted for supplementary references but the primary measurement remains SI (mm/s).
- Additional guidance on measurements in cold climates (e.g., winterisation, condensation effects on transducers) is included in an informative annex.
- References to other CSA standards (e.g., C22.1 – Canadian Electrical Code) replace international references where applicable.
When purchasing equipment that will operate in Canada, requiring compliance with CAN CSA C50‑14 ensures both international consistency and local suitability.
Practical Measurement Guidelines
For reliable results, consider the following during any vibration test according to CAN CSA C50‑14:
- Stabilise the machine at operating temperature before taking readings.
- Use a flat, clean surface for the transducer; avoid painted or rusty spots.
- For axial measurements (if required), place the sensor at the bearing housing – not on a fan cover or other sheet metal.
- If vibration levels exceed the specified limits, separate the machine from its driven load and retest (unless the load is considered part of the acceptance test).
Always verify that the machine is in good mechanical condition before testing – misalignment, unbalance of the driven equipment, or loose foundation bolts can produce readings that do not reflect the machine’s inherent vibration quality.
Compliance and Certification
Compliance with CAN CSA C50‑14 can be demonstrated by:
- Factory routine testing: Every machine is tested after assembly. The vibration level must not exceed the limit applicable to its shaft height and mounting category. Results are recorded and may be furnished upon request.
- Type testing: A representative specimen of a design family undergoes full vibration characterisation. This qualifies the entire series.
- Site acceptance testing: Vibration is measured after installation on the intended foundation. Limits are slightly relaxed to account for field installation effects – typically 1.25× the factory limits unless otherwise agreed.
Machines that meet the criteria may be marked as “CSA C50‑14 compliant” on the nameplate, along with a reference to the measured vibration grade (if requested). Third‑party certification by a recognised testing laboratory is common for machines used in hazardous locations or critical processes.
Non‑compliance consequences: Exceeding the vibration severity limits can lead to accelerated bearing wear, rotor rub, insulation damage, and in extreme cases, catastrophic failure. In many jurisdictions, non‑compliant machines may not be accepted for installation without an approved deviation document.
The standard is also frequently referenced in purchase specifications for motors and generators, making it a practical requirement for OEMs supplying the Canadian market.
To maintain compliance over the machine’s life cycle, periodic vibration monitoring per ISO 10816‑1 is recommended. If trending shows levels approaching the CAN CSA C50‑14 limits, maintenance should be scheduled before the threshold is breached.
Q: How does CAN CSA C50‑14 (2018) differ from the older CAN CSA C50‑14 (2011)?
A: The 2018 edition aligns with IEC 60034‑14:2018, which introduced refined limits for very large machines (H > 630 mm), clarified the concept of “flexible mounting” by providing quantitative criteria (isolator stiffness), and added new guidance for measurement uncertainty and transducer selection. Canadian national deviations were also updated to reference current CSA Electrical Codes.
A: The 2018 edition aligns with IEC 60034‑14:2018, which introduced refined limits for very large machines (H > 630 mm), clarified the concept of “flexible mounting” by providing quantitative criteria (isolator stiffness), and added new guidance for measurement uncertainty and transducer selection. Canadian national deviations were also updated to reference current CSA Electrical Codes.
Q: Are vibration limits different for machines driven by variable frequency drives (VFDs)?
A: Yes. CAN CSA C50‑14 includes notes stating that harmonic content from VFD supply can affect vibration readings. Measurements should be made at the rated fundamental operating speed, and special filtering may be needed to separate the carrier‑frequency components from the mechanical vibration. The standard allows parties to agree on additional acceptance criteria for machines supplied by inverters.
A: Yes. CAN CSA C50‑14 includes notes stating that harmonic content from VFD supply can affect vibration readings. Measurements should be made at the rated fundamental operating speed, and special filtering may be needed to separate the carrier‑frequency components from the mechanical vibration. The standard allows parties to agree on additional acceptance criteria for machines supplied by inverters.
Q: What if a machine is tested on a flexible mount but will be installed on a rigid foundation?
A: The standard requires that acceptance testing be performed on the mounting arrangement that will be used in field installation. If that is unknown, the more conservative (rigid mounting) limits should be used. Agreement between manufacturer and purchaser can override this requirement.
A: The standard requires that acceptance testing be performed on the mounting arrangement that will be used in field installation. If that is unknown, the more conservative (rigid mounting) limits should be used. Agreement between manufacturer and purchaser can override this requirement.
Q: Are displacement limits ever used under CAN CSA C50‑14?
A: Displacement limits are permitted only when the dominant vibration frequency is below 10 Hz, because velocity measurements become insensitive to low‑frequency, high‑amplitude motion. For machines such as low‑speed hydro generators or certain wind‑turbine generators, displacement criteria may be specified in an annex or by mutual agreement. For the vast majority of 2‑ to 12‑pole machines, velocity limits are sufficient.
A: Displacement limits are permitted only when the dominant vibration frequency is below 10 Hz, because velocity measurements become insensitive to low‑frequency, high‑amplitude motion. For machines such as low‑speed hydro generators or certain wind‑turbine generators, displacement criteria may be specified in an annex or by mutual agreement. For the vast majority of 2‑ to 12‑pole machines, velocity limits are sufficient.
This article is for informational purposes only. Always refer to the official CAN CSA C50‑14 (2018) document published by CSA Group for complete requirements. Last updated 2026.
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