What is the minimum size copper supply-side bonding jumper required for conductors sized at 500 kcmil copper in flexible metal conduit?

The minimum size copper supply-side bonding jumper for conductors sized at 500 kcmil copper is determined based on the requirements in the National Electrical Code (NEC) that specify the proper sizing based on the largest ungrounded conductors present in the system.

For conductors sized at 500 kcmil, the bonding jumper must be sized according to NEC Table 250.122, which outlines the ampacity and corresponding bonding jumper sizes based on the overcurrent protection device's rating. The 1/0 AWG copper supply-side bonding jumper is the size that meets the NEC requirements for bonding when using conductors of this size.

This choice reflects the appropriate size needed to ensure safety and compliance with electrical regulations, confirming that the bonding jumper is capable of handling potential fault currents. The other options would not meet the necessary specifications outlined in the code for this application, as they either fall below the minimum required size for safe operation or do not correspond adequately to the standard practices for such installations.