There are 2 common wire flamability retardant spec in the industry： VW-1 and FT-1.
The VW-1 test evaluates the wire's resistance to vertical fire spread, while the FT-1 test evaluates the wire's resistance to fire spread along the horizontal axis. The tests are carried out according to the UL standards.
During VW-1 testing, wires are subjected to a flame for a specified period and observed for their ability to resist flame spread. In contrast, FT-1 testing involves a wire being subjected to a flame for a short period, and then the flame is removed to observe the wire's recovery.
VW-1 and FT-1 wires are suitable for different installations. VW-1 wires are typically used in vertical installations, such as walls or conduits, where fire can spread rapidly and cause significant damage. Therefore, the VW-1 standard requires wires to resist vertical flame propagation, minimize afterglow, and not drip during the burning process.
On the other hand, FT-1 wires are designed for use in horizontal installations, such as floors and ceilings. The FT-1 standard requires wires to resist flame spread along the cable's length and self-extinguish within a specified time after the removal of the flame.
In summary, both VW-1 and FT-1 wires are essential for electrical safety, and their use depends on the installation's orientation. These wires are designed to delay the spread of fire and reduce the risk of property damage, injury, and loss of life. Therefore, we should always prioritize the use of fire-resistant wires and adhere to the specified standards to ensure maximum safety.
