Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
CSA C22.2 No. 83.1-07 (R2017) Standard for Electrical Non-Metallic Tubing (ENT) and Fittings: Technical Overview and Compliance Guide
Understanding the Canadian requirements for ENT systems in electrical installations
CSA C22.2 No. 83.1-07 (R2017) is a critical standard under the Canadian Electrical Code framework, specifying the requirements for Electrical Non-Metallic Tubing (ENT) and its associated fittings. As a pliable, corrugated raceway system, ENT offers a lightweight, corrosion-resistant alternative for protecting electrical conductors in various building infrastructure applications. This article provides a technical analysis of the standard’s scope, key requirements, testing protocols, and essential compliance considerations for manufacturers, specifiers, and installers.
1. Scope and Application
CSA C22.2 No. 83.1-07 (R2017) applies to electrical non-metallic tubing (ENT) and ENT fittings constructed of non-metallic materials such as polyvinyl chloride (PVC) or polyethylene (PE). The tubing is corrugated, circular in cross-section, and intended for use as a raceway for electrical conductors and cables in accordance with the Canadian Electrical Code, Part I (C22.1).
The standard covers ENT systems rated for voltages up to 600 V and conductor operating temperatures up to 90 °C, with ambient temperature limits up to 75 °C. It includes requirements for both tubing and fittings to ensure a complete raceway system that provides mechanical protection, electrical insulation, and fire performance characteristics suitable for installation in buildings and industrial locations.
ENT is classified by its crush resistance, impact resistance, and temperature rating. The standard defines several types based on these properties, including standard and reinforced constructions. Fittings include couplings, connectors, adapters, and end bells, all designed to mechanically join and secure the tubing.
Exclusions: The standard does not cover metal tubings, rigid PVC conduit, flexible metallic tubing, or raceways for communication cables unless specifically referenced in the CEC.
2. Technical Requirements and Performance Criteria
The standard establishes detailed requirements for materials, dimensions, mechanical strength, thermal aging, flame propagation, and electrical insulation. The following table summarizes key performance requirements for ENT systems:
| Requirement | Test Method | Acceptance Criterion |
|---|---|---|
| Crush Resistance | Compression at specified load | Diameter reduction ≤ 30% |
| Impact Resistance | Drop weight test at −20 °C | No cracking or splitting |
| Flame Propagation | CSA FT4 vertical tray test | Flame travel ≤ 1.5 m |
| Heat Aging | 168 h at 100 °C | No cracks after mandrel bend |
| Dielectric Strength | Withstand 2500 V for 1 min | No breakdown |
| Cold Bend | Bend at −20 °C | No visible cracks |
Material Requirements: The tubing must be made from thermoplastic compounds that are resistant to ultraviolet (UV) radiation if labeled for sunlight exposure, and shall have a minimum temperature rating of 90 °C for conductor operating temperature.
Dimensional Requirements: Tube diameters, wall thicknesses, and corrugation spacing are specified to ensure compatibility with fittings and to meet mechanical performance. Standard trade sizes range from 1/2″ (16 mm) to 4″ (103 mm) nominal diameter. The standard includes detailed tolerance tables to guarantee interchangeability between different manufacturers’ products when certified as a system.
Flame Propagation and Smoke: ENT must meet the requirements of CSA C22.2 No. 0.3 for flame propagation and smoke generation. The standard specifies the FT4 vertical flame test as the method to limit flame spread. Products meeting a lower smoke generation may be classified as “FT4-25” or similar.
3. Testing and Certification Highlights
Certification to CSA C22.2 No. 83.1 is typically performed by the Canadian Standards Association (CSA Group) or recognized third-party organizations. The certification process includes design review, prototype testing, and factory production line testing.
Design and Prototype Evaluation: Initial testing of tubing and fittings for all performance requirements, including mechanical, thermal, electrical, and fire performance. Samples are conditioned at specified temperatures and humidity.
Production Line Testing: Routine tests on each production batch to verify critical parameters such as dimensions, crush resistance, and marking durability.
Marking Requirements: Each length of tubing and each fitting must be permanently marked with the manufacturer’s name or trademark, trade size, type designation, and certification mark. Typical marking: “CSA C22.2 No. 83.1 ENT 90 °C 600 V”.
Retesting: If materials or processes change, the product must be retested to maintain certification.
Tip: Ensure that both the tubing and the fittings are certified as a complete system under the same certification file. Mixing components from different manufacturers may void compliance and reduce raceway performance.
Warning: ENT is not listed for direct earth burial unless specifically marked as “Sunlight Resistant” and rated for direct burial. Always consult the manufacturer’s instructions and the Canadian Electrical Code Part I for proper installation conditions.
4. Compliance Notes for Manufacturers and Installers
For Manufacturers:
- Develop a rigorous quality control program to ensure consistent material and dimensional properties.
- Maintain certification by showing ongoing compliance via annual factory inspections and follow-up testing.
- Keep abreast of amendments; the 2017 reaffirmation updates references to other CSA standards and may introduce new requirements.
For Specifiers and Installers:
- Always use certified ENT and fittings that bear the CSA mark or equivalent certification from an accredited body.
- Follow the installation requirements of the Canadian Electrical Code (Section 12, Raceways) for support spacing, bending radius, and burial depth.
- For installations in plenum spaces, confirm that the ENT carries a low-smoke rating, often designated as CMP (Canadian Plenum). Standard ENT is not suitable for plenum use due to smoke generation.
- Ensure that the tubing is not installed in concrete unless specifically approved for direct embedment.
Success: Using CSA certified ENT and fittings simplifies inspection approvals and ensures the installation meets the safety requirements of the Canadian Electrical Code.
Danger: Do not install ENT in areas subject to physical abuse without additional protection, such as rigid conduit or metallic raceway. ENT is designed for general-purpose raceway use and may not withstand severe impact.
Frequently Asked Questions
Q: What is the difference between CSA C22.2 No. 83.1 ENT and flexible metal conduit (FMC)?
A: ENT is non-metallic, lighter, and offers corrosion resistance, while FMC is metallic and provides better electromagnetic shielding and physical protection. ENT is allowed in most dry and damp locations but has limitations in plenums and where exposure to physical damage is high.
A: ENT is non-metallic, lighter, and offers corrosion resistance, while FMC is metallic and provides better electromagnetic shielding and physical protection. ENT is allowed in most dry and damp locations but has limitations in plenums and where exposure to physical damage is high.
Q: Can CSA C22.2 No. 83.1 ENT be used in wet locations?
A: Yes, but only if the tubing and fittings are explicitly listed for wet locations and marked accordingly. Standard ENT is suitable for damp locations; for wet locations (e.g., outdoors, conduits exposed to moisture), ensure the product is marked as “Wet Location” and has UV resistance if exposed to sunlight.
A: Yes, but only if the tubing and fittings are explicitly listed for wet locations and marked accordingly. Standard ENT is suitable for damp locations; for wet locations (e.g., outdoors, conduits exposed to moisture), ensure the product is marked as “Wet Location” and has UV resistance if exposed to sunlight.
Q: What markings are required on a compliant ENT product?
A: At minimum: manufacturer’s name or trademark, trade size, standard number (C22.2 No. 83.1), temperature rating (e.g., 90 °C), voltage rating (600 V), and the certification mark (CSA or other accredited body). Additional markings may include “Sunlight Resistant”, “Wet Location”, or “FT4”.
A: At minimum: manufacturer’s name or trademark, trade size, standard number (C22.2 No. 83.1), temperature rating (e.g., 90 °C), voltage rating (600 V), and the certification mark (CSA or other accredited body). Additional markings may include “Sunlight Resistant”, “Wet Location”, or “FT4”.
Q: Is ENT allowed in concealed spaces (e.g., within walls or above ceilings)?
A: Yes, ENT is permitted in concealed spaces in accordance with the CEC, as long as it is installed according to the code rules and is not subject to physical damage. However, for plenum spaces above drop ceilings, you must use plenum-rated ENT (with low smoke generation) or an alternative raceway that complies with the local building code.
A: Yes, ENT is permitted in concealed spaces in accordance with the CEC, as long as it is installed according to the code rules and is not subject to physical damage. However, for plenum spaces above drop ceilings, you must use plenum-rated ENT (with low smoke generation) or an alternative raceway that complies with the local building code.
Last updated: 2026