VW-1 and FT 2 are flammability ratings used to assess the fire resistance and safety characteristics of electrical and electronic cables. While both ratings are recognized in the industry, there are important differences between them. Let's explore these differences in more detail:
1. VW-1:
VW-1 is a flammability rating established by UL (Underwriters Laboratories), a global independent safety science company. It stands for Vertical Wire Flame Test, and it is a widely used standard for assessing the flammability of cables. The VW-1 rating measures the vertical propagation of flame along a single wire or cable specimen. It is commonly used in North America.
The VW-1 test involves suspending the cable vertically and igniting it at the bottom. The flame is then timed to see how far it propagates vertically along the cable within a specific time frame. For a cable to achieve a VW-1 rating, it must self-extinguish within a certain distance and time interval after the ignition source is removed. This test helps determine the cable's resistance to flame propagation.
2. FT 2:
FT 2 is a flammability rating defined by CSA (Canadian Standards Association), a standards development and certification organization. It stands for Flame Test 2, and it is primarily used in Canada. The FT 2 rating measures the performance of cables in resisting flame spread along their length.
The FT 2 test is similar to the VW-1 test, as it also involves vertically suspending the cable and applying a flame at the bottom. However, the main difference is that FT 2 does not have specific distance and time requirements like the VW-1 rating. Instead, it focuses on whether the cable self-extinguishes within a reasonable time and does not propagate the flame excessively.
3. Differences:
- Test Parameters: The VW-1 rating specifies specific distance and time requirements for flame propagation, while the FT 2 rating focuses more on self-extinguishing characteristics without strict distance and time limits.
- Regional Application: VW-1 is predominantly used in North America, while FT 2 is specific to Canada. These ratings are recognized and required by different regulatory bodies in each region.
- Certifications: Cables meeting the VW-1 rating are certified by UL, while those meeting the FT 2 rating are certified by CSA. These certifications indicate compliance with the respective flammability standards.
When selecting cables for specific applications, it is important to consider regional requirements and regulations. For example, in North America, manufacturers may need to comply with VW-1 for products sold in the United States, or FT 2 for products sold in Canada. It is essential to verify which standards apply to the target market and ensure that the cables used meet the required flammability ratings.
It's worth noting that there may be additional flammability ratings used in different regions and industries. Manufacturers and buyers should consult the relevant standards, guidelines, and local regulations to ensure compliance and safety.