There are factors:
- Bushing Locations
- Phasing
Bushing Locations
The American National Standards Institute (ANSI) provides a universal designation for labeling transformer sides: ANSI Side 1 is the “front” of the transformer—the side of the unit that hosts the drain valve and nameplate. The other sides are designated moving clockwise around the unit: Facing the front of the transformer (Side 1), Side 2 is the left side, Side 3 is the back side, and Side 4 is the right side.
Sometimes substation bushings can be on the top of the unit, but in that case, they’ll be lined up along the edge of one side (not in the middle). The transformer’s nameplate will have a full description of its bushing layout.
Phasing
As you can see in the substation pictured above, the low-voltage bushings move from left to right: X0 (the neutral bushing), X1, X2, and X3.
However, if the phasing were the opposite of the previous example, the layout would be reversed: X0, X3, X2, and X1, moving from left to right.
The neutral bushing, pictured here on the left side, can also be located on the right side. The neutral bushing may also be located beneath the other bushings or on the lid of the transformer, but this location is less common.
Post time: Aug-26-2024