A _______________ transformer has the x1 bushing on the right side

• A. Additive
• B. Subtractive
• C. Isolated
• D. Auto

Answer: (A)

Polarity of winding connections determines where phase terminals appear and whether voltages add or subtract. When a transformer is described as additive, the windings are oriented so their voltages point in the same direction, which places corresponding phase terminals in the same relative position. In this case, the X1 terminal on the secondary end aligns so that the X1 bushing ends up on the right side in a typical schematic view. This right-side placement reflects that the windings contribute in phase with each other, producing additive behavior.

If the polarity were subtractive, the X1 terminal would appear on the opposite side because the windings oppose each other, leading to subtractive behavior. Isolated transformers emphasize galvanic isolation rather than a particular winding polarity for additive vs subtractive, and autotransformers use a single winding with taps, so the X1-right convention isn’t the defining feature there.