What must be connected together at the service entrance according to specific NEC sections?

At the service entrance, it's essential to connect the grounded conductor, the main bonding jumper (MBJ), and the grounding electrode conductor (GEC) to ensure proper grounding and bonding of the electrical system. This practice aligns with the National Electrical Code (NEC) requirements, which aim to enhance safety and reduce the risk of electric shock or fire.

The grounded conductor plays a critical role in completing the return path for electrical current and is typically identified by a specific color code. The MBJ is used to establish a connection between the grounded conductor and the grounding system, thereby ensuring that any fault current will be safely directed to the earth. The GEC connects the grounding system to the grounding electrodes, which safely dissipates fault currents into the ground.

By combining these three components at the service entrance, the electrical system gains enhanced stability and safety, reducing the risks associated with electrical faults. This integrated approach also facilitates effective operation of protective devices and compliance with electrical codes, which are developed to maintain safe operating conditions within electrical installations.