Is only one service permitted to supply a building or structure?

A single service supplying a building or structure is typical and often specified by national and local electrical codes, including the National Electrical Code (NEC) as adopted by Ohio. The reason for this requirement is primarily to ensure the safety, reliability, and practicality of electrical distribution within the building. Limiting a building to one service helps to facilitate simpler design, reduces the potential for confusion when managing the electrical system, and minimizes the risk of overloading the service.

In many scenarios, a single service adequately meets the needs of both residential and commercial structures. While there may be exceptions where multiple services are allowed—in large commercial installations or unique cases where the load exceeds the capacity of a single service—these situations typically require specific justification and compliance with additional regulations. It's essential to consult local codes and regulations to confirm the applicability in specific scenarios, but generally, the permission for a single service aligns with the goal of maintaining a streamlined, efficient electrical system within a building.