For installations exceeding 600 volts, which size bonding jumper is required according to NEC?

For installations exceeding 600 volts, the National Electrical Code (NEC) specifies that a minimum size of 6 AWG bonding jumper is required. This requirement ensures that the bonding jumper is adequately sized to conduct any fault current that may occur, thus providing a low-resistance path back to the source. The primary function of a bonding jumper is to ensure that all metallic parts of electrical equipment and structures are at the same electrical potential, minimizing the risk of electrical shock and enhancing the safety of the electrical system.

The sizing of conductors for bonding is crucial because if the jumper is too small, it may not be capable of carrying the fault current, leading to overheating and potentially causing the electrical system to fail. In systems that operate at higher voltages, like those exceeding 600 volts, the risks associated with inadequate bonding size are heightened. Therefore, the NEC establishes a minimum size of 6 AWG for these applications to maintain reliability and safety standards in electrical installations.