FT-4 is a CSA designation for the Vertical Tray Flame Test used to evaluate flame spread performance of cables installed in vertical trays.
FT-4 is a flame performance classification established by the Canadian Standards Association for cables intended for vertical tray installations. The FT-4 test evaluates how a group of cables behaves when exposed to a controlled flame source in a vertical configuration that simulates installation in cable trays or similar support systems.
During the Vertical Tray Flame Test, multiple cable samples are mounted in a ladder style tray and subjected to a standardized ignition source for a defined duration. The objective is to measure flame spread along the cable bundle and determine whether combustion remains within specified limits. To achieve an FT-4 rating, the cable must demonstrate restricted flame propagation and controlled burning behavior under the defined test conditions.
In commercial and industrial facilities, vertical cable trays are commonly used to organize and support large quantities of power, control, and communication cables. Because these trays can extend across multiple levels or through significant building sections, flame spread performance is a critical safety consideration. An FT-4 designation indicates that the cable has been evaluated for use in these grouped vertical installations within Canadian regulatory frameworks.
FT-4 differs from individual conductor flame tests such as FT-1, which evaluate single cable samples. The tray configuration used in FT-4 testing more closely represents real world installation conditions where multiple cables are bundled together. This makes the FT-4 rating particularly relevant for large scale infrastructure projects and industrial environments.
While FT-4 is a Canadian designation, its performance intent is comparable to other vertical tray flame tests recognized in different jurisdictions. When specifying cable for multinational projects, it is important to confirm that flame performance ratings align with the governing code requirements for the installation location.
Overall, FT-4 represents a structured evaluation of flame spread characteristics for cables installed in vertical tray systems, supporting enhanced fire performance in commercial and industrial cable infrastructure.
Canadian Standards Association