When can additional disconnects be added to a service?

The correct choice is based on the idea that the addition of disconnects to a service can be permissible when the original design has been configured to allow for such modifications. When a service is installed, the original design typically considers factors such as load capacity, available spaces, and safety regulations, which can dictate whether additional disconnects can be integrated without compromising the safety or functionality of the electrical system.

If the initial design includes provisions for future expandability, then adding disconnects becomes a viable option as long as these additions align with the original parameters. This implies that considerations like proper sizing, location, and access to the disconnects must be maintained according to the standards set forth in the NEC.

While other choices address different scenarios, they don't present a foundational guideline. The requirement of utility specifications, overall load calculations, or special circumstances does not universally apply to all situations regarding the addition of disconnects. Therefore, adhering to the original design allows for standardized modifications while ensuring compliance with safety standards and efficient system operation.