Question: is thhn wire rated for cable tray?
Answer: THHN/THWN is approved for up to 600V and is dual rated. This means it can be used in dry locations not exceeding 90 degrees Celsius and 75 degrees Celsius in wet locations, as listed by the Underwriters Laboratory (UL). It is VW-1 rated, and AWG sizes 1/0 and larger are cable tray (CT) rated.