How much current can three 1/0 AWG XHHW-2 aluminum conductors carry when installed in RMC at 105°F?

To determine how much current three 1/0 AWG XHHW-2 aluminum conductors can carry when installed in rigid metal conduit (RMC) at 105°F, it is essential to refer to the National Electrical Code (NEC) ampacity tables.

For aluminum conductors, the NEC provides specific ampacity ratings based on conductor size, insulation type, and installation conditions. The 1/0 AWG aluminum conductor typically has a base ampacity of 130 Amperes at an ambient temperature of 75°F. However, since the operating temperature is 105°F in this scenario, an adjustment needs to be made due to the increase in temperature which affects the ampacity.

Using the NEC temperature correction factors, the ampacity reduces because aluminum conductors are more susceptible to temperature increases compared to copper. The adjustment factor at 105°F would decrease the ampacity from its base value. The relevant correction factor for this temperature can be found in NEC tables.

After applying the appropriate temperature correction factor to the 130 A base rating, the allowable current for the three conductors installed in RMC can be calculated. The final adjusted rating will lead you to the answer of 117 A, which aligns with the calculations based on