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Understanding CSA C22.2 No. 106-05 (2014): Control and Auxiliary Devices for Electric Motor Control Equipment
Scope, Technical Requirements, and Compliance for Industrial Motor Control Installations under the Canadian Electrical Code
1. Scope and Field of Application
CSA C22.2 No. 106-05 (2014) is a harmonized standard developed under the Canadian Electrical Code, Part II framework. It applies to control and auxiliary devices intended for use with electric motor control equipment in industrial, commercial, and similar installations. Typical devices covered include pushbuttons, pilot lights, selector switches, contactors, relays, control transformers, and similar components that form part of motor control circuits or auxiliary circuits up to 600 V AC or 250 V DC.
The standard does not cover main power disconnect switches, circuit breakers, or motor overload relays that are covered by separate product standards. Instead, it focuses on the interface and logic components that enable safe operation, indication, and sequencing of motor starters and controllers.
Tip: For devices that combine control and power functions (e.g., combined starter and relay), both CSA C22.2 No. 106-05 and the appropriate power device standard may apply. Verify the scope for each component separately.
2. Technical Requirements – Construction and Performance
2.1 Construction
All control and auxiliary devices must be constructed to provide adequate protection against electric shock, fire, and mechanical hazards. Requirements include:
- Enclosures: Shall be of suitable material and thickness, offering at least the protection required for the intended environment (e.g., NEMA/CSA enclosure types).
- Spacing: Minimum clearance and creepage distances per impulse withstand voltage levels, as defined in CSA C22.2 No. 0 (General Requirements).
- Terminals: Must accommodate the conductor sizes specified in the Canadian Electrical Code and be marked accordingly.
- Interlocking: Where movable parts can cause hazards, mechanical or electrical interlocks are required.
2.2 Performance
Devices are subjected to a series of type tests to verify performance under normal and abnormal conditions. Key tests include:
| Test | Parameters | Acceptance Criteria |
|---|---|---|
| Dielectric Voltage Withstand | 1,500 V–2,200 V for 60 s (depending on rated insulation voltage) | No breakdown or flashover |
| Temperature Rise | At rated continuous current in free air | Temperature rise ≤ 65 °C (copper conductors) |
| Overload & Endurance | Load cycling at 1.25 × rated current for defined number of operations | No electrical or mechanical failure |
| Short-Circuit Withstand | Short-time withstand current (if applicable) or fusing limits | No rupture or ignition |
Warning: Temperature rise tests must be performed in a still-air environment unless the device is intended for forced-air ventilation. Incorrect test configuration can lead to non-compliance.
2.3 Marking and Documentation
Each device must be permanently marked with:
- Manufacturer’s name or trademark
- Catalog number or equivalent identifier
- Rated voltage, current, and frequency
- Enclosure type rating (if provided)
- Date code or traceability information
Instructions for installation, operation, and maintenance must be supplied with the device or referenced in readily available documentation.
3. Compliance and Certification Considerations
While CSA C22.2 No. 106-05 is a safety standard, compliance with its requirements is mandatory for products sold or installed in Canada. Certification marks from recognized organizations (e.g., CSA, cUL, QPS) verify that a product has been evaluated to this standard.
3.1 Relation to UL 508
CSA C22.2 No. 106-05 is technically harmonized with UL 508, “Standard for Industrial Control Equipment.” Differences are limited to Canadian deviations, primarily regarding supply voltages, conductor sizes, and specific marking requirements. A product certified to both standards can carry a dual CSA/UL mark.
Good practice: When designing for both Canadian and US markets, design to the more stringent requirement of the two standards or use the harmonized values. This simplifies certification and reduces testing costs.
3.2 Field Installations
Installations must also comply with the Canadian Electrical Code, Part I (CSA C22.1). The use of certified control and auxiliary devices simplifies inspection and ensures compliance with Sections 28 and 42 of the CE Code for motor control circuits and auxiliary devices.
3.3 Updates from Earlier Editions
The 2014 edition of CSA C22.2 No. 106-05 includes clarifications on spacing requirements, revised marking provisions for short-circuit current ratings (SCCR), and alignment with new IEC harmonization trends in impulse voltage levels. It also introduced updated test sequences for electronic control devices.
Critical: The SCCR of a control device must be coordinated with the available fault current at the point of installation. Using devices without proper SCCR marking may violate CE Code requirements and create fire hazards.
Frequently Asked Questions
Q: Does CSA C22.2 No. 106-05 apply to programmable logic controllers (PLCs)?
A: No. PLCs are covered by other product standards (e.g., CSA C22.2 No. 0.11 or IEC 61131-2). However, discrete relays, pushbuttons, and similar I/O components within a PLC system are within scope of No. 106-05.
A: No. PLCs are covered by other product standards (e.g., CSA C22.2 No. 0.11 or IEC 61131-2). However, discrete relays, pushbuttons, and similar I/O components within a PLC system are within scope of No. 106-05.
Q: What is the difference between “control device” and “auxiliary device” under this standard?
A: Control devices are those intended to directly control the operation of motor controllers (e.g., pushbuttons, selector switches). Auxiliary devices provide indication, interlocking, or logic functions (e.g., pilot lights, limit switches). Both categories are covered, but performance requirements may vary depending on the duty cycle.
A: Control devices are those intended to directly control the operation of motor controllers (e.g., pushbuttons, selector switches). Auxiliary devices provide indication, interlocking, or logic functions (e.g., pilot lights, limit switches). Both categories are covered, but performance requirements may vary depending on the duty cycle.
Q: Can a device certified to UL 508 be accepted in Canada without additional testing?
A: Not automatically. The product must also be evaluated to the Canadian deviations of CSA C22.2 No. 106-05, or the manufacturer may request a dual certification. Many NRTLs (e.g., CSA, UL) offer combined certification programs based on the harmonized requirements.
A: Not automatically. The product must also be evaluated to the Canadian deviations of CSA C22.2 No. 106-05, or the manufacturer may request a dual certification. Many NRTLs (e.g., CSA, UL) offer combined certification programs based on the harmonized requirements.
Q: Are there specific marking requirements for ambient temperature ranges?
A: Yes. If the device is rated for other than a 40 °C ambient, the marked ambient temperature rating must be indicated. This is often found on devices used in high-temperature applications such as foundries or boiler rooms.
A: Yes. If the device is rated for other than a 40 °C ambient, the marked ambient temperature rating must be indicated. This is often found on devices used in high-temperature applications such as foundries or boiler rooms.
— Published for technical reference in 2026. Always verify the latest edition of CSA C22.2 No. 106-05 in effect as standards are periodically updated.