The need often arise where the default circuit naming convention in Revit needs to be modified or changed to suit company standards.
When selecting a panel, in the Electrical - Circuiting area of the Properties Panel, a property called Circuit Naming exists. By default, no circuit naming is applied to your panels. The circuits will thus be named numerically.
When changing the Circuit Naming to Panel Name, as can be seen from the panel schedule below, the panel name will now be added as a prefix to the circuit name.
With Circuit Naming set to Prefix, you will be able to add both a Circuit Prefix, as well as Circuit Prefix Separator.
A Standard Circuit Naming will show only the circuit numbers
Circuit Naming by Phase adds the default Phase A, Phase B, and Phase C prefix to circuits.
Should the circuit phase prefixes need to change, it can be accessed by changing the General Electrical Settings for the project and/or template.