Version: 10.2.1c and 10.2.1.c SP3 |
Appendix > Secondary Circuit Analysis Calculations |
Secondary Circuit Analysis relies on several calculations to perform 'what if' scenarios. These calculations are based on the following assumptions:
If the transformer is 3-phase, each service load is assumed to be a 3-phase balanced load, and its total value is divided by three. In this case it is also assumed that load current flows in one direction only (i.e., it doesn't need to return via a neutral conductor).
If the transformer is 1-phase, each service load is assumed to be on the same phase as every other service load, and the load current is assumed to flow in both a phase and a neutral (return) conductor.
Given these interpretations, one can generally expect voltage drops in a circuit headed by a 1-phase transformer to be about six times greater than voltage drops in a similarly configured and loaded circuit headed by a 3-phase transformer.
This section describes the following secondary circuit analysis calculations: