According to the Autodesk Revit MEP User’s Guide (Chapter 17 – Electrical Systems), when creating power and lighting circuits, Revit enforces specific compatibility rules to ensure the accuracy and integrity of electrical systems. The document explicitly states:

“Circuits connect similar electrical components to form an electrical system. Once created, you can edit circuits to add or remove components, connect a circuit to a panel, add wiring runs, and view circuit and panel properties… A component can be connected in a circuit if it is compatible with the other components in the circuit and if it has an available connector.”

Furthermore, it continues:

“When circuits are created for a power system, only compatible devices can be connected. All devices in a circuit must specify the same distribution system (voltage and number of poles). The distribution system can be specified by type parameters or instance parameters. When you create a circuit where all the devices have the distribution system specified as instance parameters, Revit MEP displays a Specify Circuit Information dialog where you can specify values for the number of poles and voltage prior to creating the circuit.”

Additionally, the documentation clarifies that circuits must exist within the same project model to maintain system logic and consistency. It explains that “circuits connect similar electrical components within a particular system,” which implicitly enforces that items must reside in the same model file. Revit’s data structure does not allow cross-model circuit connections, since circuit logic, load calculations, and panel assignments depend on shared model parameters and hosted relationships between electrical families.

Therefore, the two rules enforced by Revit when creating a power circuit are:

A. Items on the circuit must be in the same model.This ensures data integrity and consistency across electrical systems, as circuits cannot span multiple linked models.

C. Items on the circuit must be assigned the same voltage definition.This guarantees that only devices with matching voltage and pole configurations can be logically and electrically connected to the same circuit.

Other options, such as requiring apparent load values or association with transformers, are not mandatory for circuit creation—they are design considerations applied after circuits are established. Worksets (option D) manage collaboration, not circuit validity.

Verified Reference:

Autodesk Revit MEP 2011 User’s Guide, Chapter 17 “Electrical Systems,” Sections Creating Circuits and Creating Power and Lighting Circuits, pp. 461–463.