What is the minimum size aluminum THW service-entrance conductors required for a load of 120 amperes on a 120/240-volt system?

To determine the minimum size aluminum THW service-entrance conductors for a load of 120 amperes on a 120/240-volt system, it is essential to refer to the National Electrical Code (NEC) guidelines, specifically Table 310.16, which provides conductor ampacities based on their size, insulation type, and the ambient temperature conditions.

For aluminum conductors, the ampacity for a size 1/0 AWG under standard conditions is typically rated for at least 150 amperes. This means that a 1/0 AWG aluminum conductor is sufficient to handle a load of 120 amperes safely without overheating or exceeding its rated capacity. The conductor's size also accounts for factors such as installation method and environmental conditions, which might require adjustments.

Selecting a conductor size that can carry the expected current load is crucial for safety and efficiency. In this case, the 1/0 AWG aluminum THW conductor is suitable and provides a margin for safety and potential future increases in load. Therefore, it is important not to choose a conductor that is too small, as this could lead to overheating and potential fire hazards.

The sizes about other choices either do not meet or exceed the required parameters for this specific