What is the allowable ampacity of each conductor where 4 current-carrying 10 AWG, THW copper conductors are installed in a raceway at an ambient temperature of 70 degrees Fahrenheit?

To determine the allowable ampacity of 10 AWG THW copper conductors, it is crucial to consult the National Electrical Code (NEC) as well as relevant tables for conductor ampacities based on the number of conductors and their installation conditions.

For 10 AWG copper conductors, the base ampacity in a raceway at an ambient temperature of 70 degrees Fahrenheit is typically referenced from NEC Table 310.16. According to this table, a single 10 AWG copper conductor can normally handle 30 amps under standard conditions. However, when multiple conductors are in the same raceway — in this case, four current-carrying conductors — it's necessary to apply a correction factor due to increased heating from the additional wires.

The NEC specifies that when three to six conductors are bundled together, the ampacity must be reduced by applying a 10% adjustment factor. Therefore, starting from the 30 amps, if we reduce this by 10%, we arrive at 27 amps. Since there can be some rounding, this generally can be interpreted within the context of allowable amps, where 28 amps is a suitable answer when accounting for the conditions stated.

Thus, this particular answer emphasizes understanding the