Which conductor type is suitable for carrying a continuous load at elevated temperatures up to 75°C?

The conductor type suitable for carrying a continuous load at elevated temperatures up to 75°C is XHHW. This designation indicates that the wire is designed to withstand higher temperatures and is typically used in applications where it may be exposed to elevated heat. XHHW conductors are made with a cross-linked polyethylene (XLPE) insulation, which allows them to operate at temperatures that exceed standard ratings, making them ideal for environments where heat is a factor.

In contrast, other options may not provide the same level of heat resistance or suitability for continuous loads at elevated temperatures. For instance, THWN is rated for wet locations and is designed to handle up to 90°C in dry applications but only 75°C in wet conditions, making it less ideal for continuous loads at 75°C. TW conductors are generally rated for lower temperatures and specific applications, while UF (Underground Feeder) conductors are primarily designed for underground installation and have limitations regarding their temperature ratings and continuous load capacity. Hence, XHHW stands out as the most appropriate choice for the specified conditions.