How Phase Constraints Are Interpreted
The “Phase of conductors and devices” option on the Electric Traces tab of the Tracing Options form offers a comprehensive list of phasing choices. It is important to understand the precise way in which the electric tracing functions interpret each of those choices.
An edge is included in trace results if and only if the set of phases that pass through the edge, coming from one or more circuit sources, is compatible with the Phases constraint specified in the tracing options form. For example, if the “Phase of conductors and devices” field is set to At Least AB, only edges that have both A and B phases will be included in the trace results (this means edges that have AB or ABC phases). Note that if the Feeder Manager Setting to use conductor phasing is turned on, any phases that are not included in an edge’s phase designation will not pass through the edge.
Junctions Representing Transformers and Switching Devices
Junctions may represent transformers, switching devices, or any device that can block power flow on one or more electrical phases (e.g., switches, fuses, reclosers, etc.). These junctions are included in trace results only if the set of phases that reach the junction can pass into the device, according to the device’s phase designation.
All Other Junctions
A junction representing anything other than a transformer or a switching device (e.g. streetlight, lightning arrestor, voltage regulator, capacitor, etc.) is included in trace results only if the set of phases that reach the junction is compatible with the “Phase of conductors and devices” option specified on the Electric Traces tab. The phases reaching the junction may come from one or more circuit sources. The set of phases ignores the phase designation of the device represented by the junction.
Phase constraints, as applied to any junction not representing either a transformer or a switching device, reflect the phases that reach up to the junction from any circuit source -- which may be more than the phases that actually touch or pass into the equipment associated with the junction feature.