A key component of transformers is that they can tap one or more of the available phases of a primary to provide service voltage. To correctly determine the status of the secondary and service wire when a single phase transformer taps a three-phase line, Feeder Manager uses the phase assignment of the transformer and voltage level attributes on conductor features to control tracing through the transformer.
If the voltage level of the arriving conductor is the same as that for another conductor connected at that junction, then Feeder Manager treats the same-voltage wire as a primary and will continue to trace it regardless of the phasing of the transformer. If, on the other hand, the voltage level of a wire is different than that of the arriving conductor, then it is considered to be a wire that goes through the transformer. Feeder Manager will only trace those wires that go through the transformer when it is tracing for the phase(s) assigned to the transformer.
This means that conductors require a field with the model name OPERATINGVOLTAGE. Minerville uses subsets of the Master Operating Voltage domain to assign a code representing the voltage. However, Feeder Manager requires that an additional domain called FdrMgrVoltageCode be defined but NOT assigned to this operating voltage field. The FdrMgrVoltageCode domain is logically independent of the other voltage domains (in the Minerville database these include Electric Line Voltage and Electric Device Operating Voltage, both subsets of the Master Operating Voltage domain). The "assignment" of the FdrMgrVoltageCode domain to the field with model name OPERATINGVOLTAGE happens in the Feeder Manager software and isn't established through ArcCatalog.
In spite of its logical independence from other voltage domains, the FdrMgrVoltageCode domain shares "code" values with these domains. In Minerville, the Master Operating Voltage domain stores a series of integer Code values, each of which represents one of the possible operating voltages that could be assigned to a conductor. To each such Code value, the domain assigns a textual Description value (e.g. 4.2kV wye). Both the nominal and operating voltage domains that are assigned to the appropriate fields of devices and conductors all contain the same integer code for each voltage. These domains are assigned to data to support entry and validation by mapping the values of the operating and nominal voltage field onto strings that make sense to people.
The job of the FdrMgrVoltageCode domain is to map the values in the domain to distinct integers from 0 to 127, inclusive. The description for each code in the domain must be an integer from 0 to 127, and should be (for full tracing functionality) assigned to the code in order of increasing voltage (i.e., higher voltages map onto higher integers). Feeder Manager uses the integer values to store the voltage levels in the bits of the weight field to support tracing.