Transformer Properties

Use Transformer Properties to edit electrical properties of the transformer that affect the Voltage Drop and Fault Calculation. This dialog allows you to select a transformer and automatically populate the kVA rating, phases, and impedance from a lookup table.

To access the Transformer Properties menu, right click a transformer in the Secondary Circuit Analysis window and select Properties from the resulting menu.

The Code field is an abbreviation for the transformer currently selected, and the Description field provides an extended description of it. When a transformer from the lookup table is selected, the fields for phasing, rated kVA, and impedance cannot be edited. You can manually specify any of these properties by checking the Custom checkbox, which will enable editing in those fields (press the Select Transformer Type... button to return to the transformer from the lookup table).

The Sending voltage field can be used to specify a voltage at the primary side of the transformer that differs from the nominal circuit voltage. This value must be given in Per Unit; the default value is 1.0.

The Secondary circuit base voltage indicates the nominal, or base, voltage for the secondary circuit. When voltage drop results are displayed, the drop is defined as a deviation from this nominal value.

The Voltage (secondary bus) reflects the amount of voltage drop (sometimes called regulation) that occurs as power flows through the transformer.

Load kVA and Load power factor show the total load calculated for the transformer. At present this is simply the sum of the complex loads for all of the service points in the model. Line losses are not included, and no diversity formula has been applied.

Fault amps shows the fault current calculated at the transformer secondary.

Note: Secondary Circuit Analysis does not carry or recognize phase information on conductors. The number of phases on a conductor is determined by its transformer. This is true even if the conductor is imported from GIS and has GIS attributes indicating phase information or if conductor phasing information is present in the description field of the conductor lookup tables. Secondary Circuit Analysis ignores ALL phase information on a conductor and allows the transformer phases to imply the phases for the circuit.