What is a requirement for assemblies listed as service equipment regarding grounded conductors?

For assemblies listed as service equipment, the requirement that they shall include a main bonding jumper is crucial for safety and proper grounding practices. A main bonding jumper serves to connect the grounded (neutral) conductor to the grounding electrode system. This connection is essential because it helps to ensure that there is a clear, low-resistance path for fault currents to flow into the ground, enhancing the overall safety of the electrical system.

Additionally, the main bonding jumper facilitates the proper functioning of overcurrent protective devices and reduces the risk of potential differences that could pose a shock hazard. It is a critical part of maintaining the integrity of the electrical system, ensuring that all parts of the assembly are effectively grounded.

The importance of the main bonding jumper is reinforced by the National Electrical Code (NEC), which outlines specific requirements for bonding and grounding to improve electrical safety. This contrasts with other options that do not align with the essential function of grounding and bonding in service equipment.