What is allowed with a single set of service entrance conductors connected to the supply side of the normal service disconnecting means?

Using a single set of service entrance conductors connected to the supply side of the normal service disconnecting means to supply standby power systems is compliant with the National Electrical Code requirements. This configuration allows for a seamless transfer of power in the event of an outage, as the standby power system can take over without the need for additional disconnects or complex wiring. Standby power systems, such as generators, are intended to start automatically when there is a power loss, providing an essential function of maintaining power to critical loads.

The focus on this particular use is due to the inherent safety and operational efficiency that comes with supplying power directly from the service entrance conductors. It ensures that the necessary load can be managed properly without overloading the system, which is vital in maintaining safety standards outlined in the NEC. This practice is advantageous for residential and commercial settings where continuity of power supply is essential.

Feeding residential lighting, powering only appliances, or connecting to auxiliary generators usually involve different configurations or additional considerations in terms of load management and compliance with NEC provisions. These scenarios must meet specific requirements that could necessitate additional conductors or disconnects, making the direct connection for standby power systems the most appropriate and compliant use of a single set of service entrance conductors in this context