True or False: Single insulated conductors have a higher ampacity when installed open in free air compared to being installed in a raceway at the same ambient temperature.

The statement is true. Single insulated conductors installed open in free air do indeed have a higher ampacity than when they are installed in a raceway under the same ambient temperature conditions. This difference is primarily due to the way heat dissipation occurs in each scenario.

In free air, the conductor is exposed to ambient air, allowing for effective heat dissipation. The air around the conductor acts as a cooling medium, which helps maintain a lower operating temperature and thereby allows the conductor to carry higher currents without overheating. The airflow surrounding the conductor increases convective heat transfer, enhancing its overall thermal performance.

Conversely, when conductors are placed in a raceway, especially if it is not well-ventilated, there is limited air circulation around the conductors. This enclosure can trap heat, which can lead to elevated temperatures and subsequently lower ampacity. The inability for the conductor to adequately dissipate heat when installed in a raceway results in a reduced capacity to carry current without exceeding temperature limits.

This fundamental understanding of how different installation conditions affect thermal performance is crucial for ensuring safe and efficient electrical system design.