Main bonding jumpers must be sized in accordance with which table in the National Electrical Code?

Main bonding jumpers are critical components in ensuring the grounding and bonding system of electrical installations meets safety requirements. The National Electrical Code (NEC) specifies the sizing of these jumpers to ensure they are adequate to carry fault current without excessive heating or damage.

Table 250.102(C)(1) of the NEC provides the necessary sizing specifications for main bonding jumpers. This table outlines the minimum sizes based on the size of the service conductors or grounded conductors being used in the installation. The purpose of sizing the main bonding jumper correctly is to ensure a low-resistance path for fault currents, which is essential for the safe operation of the electrical system. This helps to maintain a stable neutral-ground reference and minimizes the potential for electric shock hazards.

The other tables mentioned do not relate specifically to the sizing of main bonding jumpers. Table 300.5 deals with the burial depth of conductors, Table 310.16 pertains to the ampacity of conductors based on their installation conditions, and Table 400.5 addresses flexible cords and cables. Each of these tables serves its own purpose in the NEC, but they do not provide the specific sizing information required for main bonding jumpers.