What is CSA HL Rating? A Guide to Hazardous Location Cables

What is CSA HL Rating? 

When sourcing armored cables for refineries, chemical facilities, or processing plants, electrical contractors and engineering estimators frequently encounter the CSA HL marking.

Passing a job site inspection or specifying the correct cable for explosive atmospheres requires understanding what this stamp means, where code mandates it, and why cables like TECK90 are the industry standard for hazardous environments.

1. What Does "HL" Stand For?

HL stands for Hazardous Location.

In Canada and across industrial sectors adhering to Canadian Standards Association guidelines, the CSA HL designation indicates that a cable has been tested and certified under CSA C22.2 No. 174 (Cables and Cable Glands for Use in Hazardous Locations).

When a cable carries the CSA HL rating on its outer jacket print legend, it is certified for safe installation in potentially explosive atmospheres where flammable gases, vapors, or combustible dusts are present.

2. Class I, Division 1 vs. Division 2: Where is HL Required?

Electrical safety codes categorize hazardous areas based on the likelihood of explosive materials being present in the air:

• Class I, Division 1 (Zone 1)

  • Definition: Flammable gases or vapors are present continuously, frequently, or during normal operations.

  • Cable Requirement: CSA HL Rating Mandatory (e.g., TECK90 with approved HL glands).

• Class I, Division 2 (Zone 2)

  • Definition: Explosive gases or vapors are present only during abnormal conditions or equipment failure.

  • Cable Requirement: Standard metal-clad or armored cable permitted under specific code conditions.

Key Rule: If a circuit passes through a Class I, Division 1 area, standard commercial armored cables (like standard indoor MC) are strictly prohibited. You must use a continuous metallic sheath or interlocked armor cable explicitly stamped CSA HL.

3. What Makes a Cable Earn the "HL" Stamp?

A cable doesn't get the HL designation just by adding metal armor. It must pass rigorous mechanical, thermal, and chemical barrier tests:

• Gas & Vapor Migration Prevention: The internal assembly must feature a tight bedding layer (such as TECK90’s inner PVC jacket) to prevent flammable gases or liquids from traveling through the interior voids of the cable into non-hazardous control rooms.

• Flame Resistance (FT4 / IEEE 1202): The cable must resist flame propagation and self-extinguish during catastrophic fire tests.

• Low-Temperature & Impact Resistance: Certified to withstand physical crushing and cold impact down to -40°C without cracking the protective armor or jackets.

• Corrosion & Acid Gas Resistance (AG14): Protective outer jackets must resist chemical degradation, moisture infiltration, and acid gas exposure.

4. Why TECK90 is the Industry Benchmark for HL Applications

While continuously corrugated welded cables (CCW / MC-HL) are frequently specified for continuous-metal-sheath environments, TECK90 Cable remains the most popular choice for 1000V hazardous location power distribution in wet, direct-burial, and tray applications.

Its dual-jacket configuration (an inner PVC bedding layer under the armor and an all-weather outer PVC jacket over the armor) provides two distinct levels of gas-tight isolation and environmental protection.

5. Critical Installation Rule: Hazardous Location Glands

Having a CSA HL-rated cable is only half the battle. The cable rating is voided if terminated with incorrect fittings.

To maintain code compliance and seal the enclosure interface:

1. Approved HL Glands: Installers must use CSA HL-certified cable glands (such as Thomas & Betts Star Teck® STH/STEX series or Crouse-Hinds TMC/TMC2X series).

2. Explosion-Proof Seals: In Division 1 areas, sealing compound or elastomeric seals inside the gland prevent gas transmission through the fitting.

3. Armor Bonding: The gland must securely grip the Aluminum Interlocked Armor (AIA) to guarantee continuous ground bonding throughout the raceway.

Sourcing CSA HL-Rated Cable for Your Next Submittal

At Wire America, our complete catalog of hazardous location wiring—including heavy TECK90 Cable (8 AWG to 750 MCM) and continuous-sheath MC-HL / CCW cables—carries official CSA HL, FT4, and AG14 compliance markings printed directly on the jacket legend. 

• Custom Cut-to-Length: We custom cut these high-performance cables by the foot, ensuring you buy only what your trench layout or cable tray requires.

• Bulk Master Reels: Available in master spool quantities for major industrial buildouts.

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Not sure which cable is right for your project? Our team is here to help!

Call us today at (833) 268-8644 or email sales@wireamerica.com.

At Wire America, we believe in genuine conversation. You'll always talk with real people who understand that every project requires careful product selection. We are a premier supplier of several different types of Industrial & Armored Cable including TECK90, Type TC-ER Tray Cable, DLO Cable, VFD Cable, Type P Cable, Type W Cable, and Generator Cables. We're here to ensure you feel educated, confident, and great about your final purchase. Feel free to give us a call to discuss your project! You can reach us at: 833-268-8644 or email sales@wireamerica.com

⚠️ Important Disclaimer: Safety and Compliance

Wire America provides this information as a guide only. Electrical installations must strictly adhere to the National Electrical Code (NEC) and all state, local, and jurisdictional requirements, which vary widely. Always consult a licensed electrician, electrical engineer, or the local inspecting authority before purchasing material or starting any electrical project. Wire America assumes no liability for the installation, use, or interpretation of these guides.