What size RHW aluminum conductors are required for a calculated load of 196 amperes?

To determine the appropriate size of RHW aluminum conductors for a calculated load, it’s important to refer to the National Electrical Code (NEC) ampacity tables. For aluminum conductors, the ampacity can vary significantly based on the conductor size and how it is installed (e.g., in conduits, in open air, etc.).

Given a calculated load of 196 amperes, the NEC tables must be consulted to find the minimum aluminum conductor size that can handle this load under normal conditions. For instance, looking at the typical ampacity charts, a 250 kcmil aluminum conductor has an ampacity that exceeds 196 amperes, making it an appropriate choice.

Conductor sizes smaller than 250 kcmil, such as 2/0 AWG or 4/0 AWG, do not provide the necessary ampacity for a 196-amp load based on the NEC guidelines. Furthermore, while 500 kcmil would also be adequate for this load, it exceeds what is necessary, leading to oversized conductors that may not be economically justified for this application.

Choosing 250 kcmil ensures that the conductors meet the load requirement without being excessively large, adhering to good electrical practice and code compliance.