How is the ampacity affected for conductors located in a conduit alongside other conductors?

The ampacity, or the maximum amount of electrical current a conductor can carry before sustaining immediate or progressive deterioration, is influenced when conductors are grouped together in a conduit. Specifically, when multiple conductors are located in close proximity, such as inside a conduit, they can generate additional heat due to the combined heat produced by the current flowing through each conductor.

As a result, the ability of each conductor to dissipate heat effectively is reduced. The heat generated cannot escape as efficiently as it would if the conductors were spaced apart or installed separately. This thermal buildup can lead to an overheating situation, potentially resulting in insulation damage or conductor failure.

To accommodate for this, standards typically require a reduction in the allowable ampacity to ensure safe operation under these conditions. This is why the correct answer reflects a decrease in ampacity for conductors located in a conduit with other conductors, ensuring that safety and performance standards are maintained.