What is the temperature rating of Type THW insulation for wiring through fixtures?

Type THW insulation is designed to have a temperature rating of 90°C. This rating indicates the maximum temperature that the insulation can safely withstand while maintaining its electrical properties and ensuring safety in electrical applications.

Using Type THW insulation in environments like wiring through fixtures, where heat can be generated, ensures that the insulation remains effective and reduces the risk of potential failures or fire hazards. This is particularly important in residential and commercial wiring scenarios where fixtures may generate heat during operation.

The other temperature ratings, such as 60°C and 75°C, correspond to different insulation types, such as TW or THHN, which are not suitable for the same applications as THW when higher temperature ratings are required. The 100°C rating is not standard for this type and exceeds the typical operational capability for THW, making it inappropriate for this context. Thus, Type THW stands out distinctly for its suitability for fixtures due to the 90°C rating, aligning with safety and performance standards in electrical installations.