Cables are critical components of modern electrical and communication systems, and their fire rating plays a vital role in ensuring safety. In Canada, the FT (Flame Test) series defines the fire resistance of cables, ranging from FT1 to FT6. Understanding these ratings is essential for architects, engineers, and electricians to ensure safe and code-compliant installations.
What Are FT Ratings?
FT ratings, established by the Canadian Standards Association (CSA), indicate a cable’s ability to resist flame propagation and minimize smoke and toxic gas release during a fire. Each number corresponds to a specific type of fire test:
FT1: Basic vertical flame test for individual wires or small cables
FT2: Horizontal tray test, suitable for open cable trays
FT4: Vertical riser test for cables running between floors
FT6: Plenum-rated, tested for flame spread and smoke in air-handling spaces
These tests help determine the safest application for each cable type in a building.
Detailed FT Series Ratings
FT1 Cable
Definition: Entry-level flame rating for single wires or small cables
Applications: Typically used in residential wiring where fire spread risk is minimal
Key Features: Basic flame resistance, suitable for dry and indoor environments
FT2 Cable
Definition: Flame rating for horizontal tray or conduit applications
Applications: Horizontal runs in open spaces or ceilings
Key Features: Moderate fire resistance, prevents flame propagation in horizontal trays
FT4 Cable
Definition: Riser-rated cable tested for vertical flame propagation
Applications: Cables that run between floors, including communication and network wiring
Key Features: High vertical flame resistance, commonly used in commercial and multi-story residential buildings
FT6 Cable
Definition: Plenum-rated cable for air-handling spaces
Applications: Ducts, drop ceilings, and other plenum spaces
Key Features: Maximum fire and smoke resistance, suitable for HVAC spaces
What is FT4 Cable Used For?
FT4 cables are one of the most widely used CSA-rated cables due to their versatility in vertical installations. Common applications include:
Riser Wiring: Connecting floors in commercial or multi-story residential buildings
Data and Communication Networks: Ethernet, fiber, and low-voltage control systems
Security Systems: Fire alarms, CCTV, and access control systems
Key Benefits of FT4:
Prevents vertical flame propagation
Meets building code requirements for riser installations
Reduces smoke and toxic gas spread between floors
Comparing FT Ratings with North American Standards (UL/NEC)
Many users are familiar with UL/NEC standards like CM, CMR, and CMP. Here’s how CSA FT ratings align:
| CSA FT Rating | Approx. UL/NEC Equivalent | Application Area |
|---|---|---|
| FT1 | VW-1 | Single wires, residential circuits |
| FT4 | CMR (Riser Rated) | Vertical riser wiring between floors |
| FT6 | CMP (Plenum Rated) | Plenum spaces and air-handling areas |
Understanding these equivalencies helps engineers and installers choose the right cable for both Canadian and North American projects.
Choosing the Right FT Cable
Factors to Consider:
Application Environment: Determine if the cable is for horizontal, vertical, or plenum installation
Building Codes: Ensure compliance with CSA and local fire codes
Cable Type: Consider signal type (data, power, or low-voltage control)
Future Expansion: Plan for additional circuits or capacity
By selecting the correct FT rating, you ensure safety, code compliance, and longevity of your building’s cabling system.
Conclusion
The FT1 to FT6 series provides a structured and reliable system for assessing fire resistance in electrical and communication cables. FT4 cable, in particular, is essential for riser applications in multi-story buildings, offering vertical flame protection and minimizing fire risk between floors.
For projects involving air-handling spaces, FT6 is mandatory, while FT1 and FT2 serve smaller or horizontal installations. Aligning CSA FT ratings with UL/NEC equivalents helps users navigate international standards and select cables safely.
Proper installation by qualified professionals is always recommended to maintain compliance and safety.
