Where must the grounding electrode conductor be connected according to NEC Article 250?

The grounding electrode conductor must be connected to the service equipment because this connection establishes a fundamental ground for the electrical system. The service equipment is the point where the utility supply connects to a building's electrical system, which makes it essential for safety and system integrity. By connecting the grounding electrode conductor here, it ensures that any fault current has a low-resistance path to the ground, minimizing the risk of electric shock and equipment damage.

Furthermore, this connection is critical for meeting the National Electrical Code (NEC) requirements, which dictate that grounding systems must be properly bonded to the service equipment for effective grounding. This prevents ground potential rise and careless grounding practices, thus ensuring safety for both people and property.