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CSA C22.2 No. 48-15 (2017): Electrical Nonmetallic Tubing and Fittings – A Technical Overview
Comprehensive analysis of the Canadian standard governing the construction, performance, and safe installation of electrical nonmetallic tubing (ENT) and associated fittings.
Scope and Purpose
CSA C22.2 No. 48-15 (2017) is a mandatory safety standard developed under the auspices of the Canadian Standards Association (CSA) as part of the C22.2 series for electrical equipment. It specifies the construction, performance, testing, and marking requirements for electrical nonmetallic tubing (ENT) and associated fittings intended for use in accordance with the Canadian Electrical Code (CE Code) Part I. This standard applies to corrugated, smooth-wall, or other nonmetallic tubing systems designed for the protection of electrical conductors and cables in dry, damp, or wet locations, including concealed or exposed installations, where ambient temperatures do not exceed the rated temperature of the system.
The purpose of CSA C22.2 No. 48-15 is to provide a consistent baseline for product safety, reliability, and interchangeability. It addresses potential hazards such as fire propagation, electric shock, mechanical damage, and environmental degradation. Compliance with this standard is typically required for products to bear the CSA mark and be accepted by Canadian inspection authorities under the CE Code.
Tip: Although CSA C22.2 No. 48-15 is a Canadian standard, it is closely harmonized with UL 1653 (Standard for Electrical Nonmetallic Tubing and Fittings). Manufacturers seeking dual certification often test to both simultaneously.
Technical Requirements
General Construction
The standard mandates that ENT and fittings be constructed from materials resistant to moisture, corrosion, and impact. Key construction aspects include:
- Material Composition: Must be a polymeric compound (e.g., PVC, PE, nylon) with suitable flame retardance and thermal stability. The material shall not sustain combustion when tested in accordance with the standard’s flammability requirements.
- Wall Thickness and Dimensions: Tubing must meet minimum wall thicknesses and internal/external diameters for the nominal trade sizes (typically 16 mm, 21 mm, 27 mm, 35 mm, 41 mm, and 53 mm). Dimensional tolerances comply with a dedicated table.
- Corrugation / Profile: The corrugation pattern, if present, shall allow flexibility while maintaining mechanical integrity under bending and compression.
Performance Testing
| Property | Requirement | Test Method |
|---|---|---|
| Flame Propagation (Vertical Tray) | Fire shall not propagate beyond the test area; flaming droplets shall not ignite underlying cotton. | CSA C22.2 No. 48 Clause 6.2 / UL 1653 similar test |
| Crush Resistance | After applying a specified load (e.g., 445 N for 5 min), the reduction in internal diameter shall not exceed 25%. | Clause 6.4 |
| Impact Resistance | No cracking visible through an eyepiece after a 1.36 kg striker dropped from 0.61 m at standard conditions. | Clause 6.5 |
| Cold Bending | No cracking or collapse after bending 180° around a mandrel at -10 °C. | Clause 6.6 |
| Heat Aging | Tensile strength and elongation after 168 h at 80 °C (or 110 °C for certain materials) must retain ≥ 80% of original values. | Clause 6.7 |
| Deflection under Heat | Deflection at 90 °C under bending load shall not exceed specified limits. | Clause 6.8 |
| Temperature Rating | System rated 60 °C (dry) / 60 °C (wet) unless otherwise marked; higher ratings (75 °C, 90 °C) permitted with appropriate testing. | Table 2 and Clause 8 |
Fittings and Adapters
Fittings (connectors, couplings, adapters, boxes) must be compatible with the tubing in terms of mechanical security, pullout strength, and sealing. For wet locations, the standard requires a watertight seal confirmed by a low‑pressure water spray test. All fittings must also withstand a pullout force of at least 89 N without separation.
Important: Use only fittings listed by a recognized certification body (e.g., CSA) for use with the specific ENT type. Mixing connectors from different manufacturers can compromise the integrity of the wiring system.
Implementation Highlights
Installation per the Canadian Electrical Code
CSA C22.2 No. 48-15 is referenced in CE Code Part I (Section 12 – Wiring Methods) for ENT systems. Key installation rules include:
- Support Intervals: ENT must be secured within 300 mm of each outlet box, junction box, or fitting, and at intervals of not more than 1.5 m.
- Bending Radius: Minimum bending radius of 5 times the tubing diameter (for hand bending) or 4 times (for factory‑formed bends).
- Temperature Derating: When used in ambient temperatures above the tubing’s rated temperature, the conductor ampacity must be derated according to C22.1 Table 5A.
- Firestopping: Penetrations through fire‑rated assemblies must be sealed using approved methods that maintain the fire‑resistance rating.
Best Practice: Always verify the temperature rating of the ENT against the expected ambient temperature at the installation site. For instance, in attic spaces where summer temperatures can exceed 60 °C, a 90 °C rated system is recommended.
Compliance and Certification Notes
CSA Marking and Certificates
Products that comply with CSA C22.2 No. 48-15 are eligible to bear the CSA Mark (or other recognized mark such as cCSAus). Marks indicate:
- Standard number and year (e.g., “CSA C22.2 No. 48-15”)
- Trade size (e.g., “16 mm”)
- Temperature rating if exceeding the default (e.g., “90°C”)
- Wet location suitability (indicated by “Wet” or “W”)
- Resistance to sunlight (if marked, e.g., “UV Resistant”)
Testing and Follow-up
Certification bodies conduct initial type testing and periodic follow‑up inspections (usually annually) to verify continued compliance. Deviations discovered during follow‑up can lead to de‑listing if not corrected within a specified timeframe.
Field Compliance and Inspection
Canadian electrical inspectors recognize CSA approved ENT as meeting the CE Code. Non‑compliance items commonly flagged include:
- Use of non‑listed fittings (e.g., generic plastic connectors from unknown sources).
- Missing or illegible marking on tubing or fittings.
- Installation in ambient temperatures above the rated value without appropriate ampacity corrections.
Warning: Using ENT that is not labeled as CSA C22.2 No. 48-15 compliant may result in an inspection failure, insurance void, and safety hazard. Always source products from reputable suppliers with valid certification.
Conclusion
CSA C22.2 No. 48-15 (2017) establishes evidence‑based requirements essential to the safe performance of electrical nonmetallic tubing in Canadian installations. From material‑specific construction rules to rigorous testing for flame propagation, crush, impact, and moisture resistance, the standard ensures that ENT systems can withstand the rigors of typical building environments. By adhering to the marking, installation, and certification guidelines outlined in this standard, designers, contractors, and electrical inspectors contribute to safer and more reliable electrical infrastructure.
Frequently Asked Questions
Q: What is the difference between CSA C22.2 No. 48-15 and the previously published No. 48‑10?
A: The 2015 edition (published in 2017 as a re‑affirmation) introduced updated requirements for cold‑bend testing, harmonized dimensional tolerances with UL 1653, and clarified marking rules for mixed‑material fittings. It also incorporated new temperature ratings for high‑ambient applications.
A: The 2015 edition (published in 2017 as a re‑affirmation) introduced updated requirements for cold‑bend testing, harmonized dimensional tolerances with UL 1653, and clarified marking rules for mixed‑material fittings. It also incorporated new temperature ratings for high‑ambient applications.
Q: Can CSA C22.2 No. 48-15 compliant ENT be used for direct burial underground?
A: Not unless the product is specifically listed for direct burial (look for additional markings such as “DB” or a wet‑location rating with supplementary test requirements). Standard ENT is intended primarily for use in walls, ceilings, and aboveground services unless otherwise marked.
A: Not unless the product is specifically listed for direct burial (look for additional markings such as “DB” or a wet‑location rating with supplementary test requirements). Standard ENT is intended primarily for use in walls, ceilings, and aboveground services unless otherwise marked.
Q: Is the standard applicable to both corrugated and smooth‑wall nonmetallic tubing?
A: Yes, the standard covers all nonmetallic tubing intended for electrical use, including corrugated (ENT), smooth‑wall (such as polyethylene raceways), and hybrid profiles, provided they meet the construction and performance criteria of the standard.
A: Yes, the standard covers all nonmetallic tubing intended for electrical use, including corrugated (ENT), smooth‑wall (such as polyethylene raceways), and hybrid profiles, provided they meet the construction and performance criteria of the standard.
Q: How does the standard address fire resistance for plenum applications?
A: CSA C22.2 No. 48-15 does not specifically address plenum ratings. For plenum spaces (used for environmental air), the CE Code requires a listed and marked “FTP” (Fire‑Tested Plenum) rating. These products are tested to CAN/ULC‑S102.2 “Surface Burning Characteristics” and are outside the scope of No. 48-15. Always verify the installation location requirements with the AHJ.
A: CSA C22.2 No. 48-15 does not specifically address plenum ratings. For plenum spaces (used for environmental air), the CE Code requires a listed and marked “FTP” (Fire‑Tested Plenum) rating. These products are tested to CAN/ULC‑S102.2 “Surface Burning Characteristics” and are outside the scope of No. 48-15. Always verify the installation location requirements with the AHJ.
© 2026 — This technical article is provided for informational purposes. For official compliance, refer to the published CSA C22.2 No. 48-15 (2017) document and consult an accredited certification body.