Refer to exhibit.

In Autodesk Revit Electrical Design, the Circuit Number for a branch circuit in a panelboard is automatically generated based on the Circuit Naming Scheme specified in the project’s Electrical Settings. This naming scheme defines how each circuit is labeled by combining predefined fields such as Panel Name, Slot Index, and Phase Label.

From the exhibit, the Circuit Naming Parameter setup is configured as:

Name

Prefix

Sample Value

Suffix

Separator

Panel

Panel

Panel

—

“-”

Slot Index

Slot Index

Slot Index

—

“/”

Phase Label

Phase Label

Phase Label

—

—

The panelboard properties show that its Circuit Naming method is set to PanelSlotPhase, which means that Revit will generate circuit numbers using the following structure:

[Panel Name] – [Slot Index] / [Phase Label]

From the exhibit:

Panel Name: P1

Slot Index (Breaker Position): 1 (since the question refers to the first breaker position)

Phase Label: A (default value for the first phase in a three-phase 120/208V Wye system)

Therefore, the Circuit Number for a single-pole circuit in the first breaker slot will be:

✅ P1-1/A

This follows Revit’s documented logic for circuit naming. According to the Autodesk Revit MEP User’s Guide (Chapter 17 “Electrical Systems”):

“The circuit numbering format is controlled by the Electrical Settings > Circuit Naming template. The default scheme combines panel name, circuit number, and phase label, using the separators defined by the user.”

Furthermore, the Smithsonian Facilities Revit Template User’s Guide confirms:

“In the default electrical configuration, circuit numbers use the format [Panel Name]-[Circuit Number]/[Phase], such as ‘P1-1/A’ for the first single-pole circuit on phase A.”

Hence, based on the provided configuration and standard electrical setup, the correct circuit number for the first single-pole breaker position in panelboard P1 is P1-1/A.