Which NEC table should be used to size the grounded conductor for a 5-kilovolt service?

The correct choice for sizing the grounded conductor for a 5-kilovolt service is based on the applicable tables in the National Electrical Code (NEC). Table 250.102(C)(1) specifically addresses the requirements for sizing the grounded conductors that are permitted to be used in conjunction with systems operating at 1000 volts or less and acknowledges conditions for higher voltages, making it suitable for the 5-kilovolt service in question.

This table provides appropriate multipliers related to the size of the ungrounded conductors, which is essential for determining the appropriate size of the grounded conductor in high-voltage applications. Using this table ensures compliance with NEC standards regarding safety and functionality in electrical installations.

Other options, while relevant to grounding requirements, do not specifically address the sizing of the grounded conductor for a 5-kilovolt service. For example, Table 250.102(B)(1) is used for sizing grounded conductors based on the larger conductor size and is not specific to high-voltage systems, and Table 250.122 addresses equipment grounding conductors based on overcurrent protection. Thus, they do not serve the needs of sizing the grounded conductor in this specific high-voltage context.