This post contains Schematics for Open Delta connected Voltage Boosting Transformers.
Transformers used are normal Isolated Power Transformers with Split Primary and Secondary coils.
Primaries are connected for "Higher Voltage", such as "240 VAC" for "120/240 VAC" ratings.
To make these Transformers "Voltage Bucking" (Voltage Reducing), simply swap Input and Output connections.
Schematics set #1; 240 VAC in, 252 VAC out 3 phase 3 wire Open Delta:
Pictorial Diagram
1 Line Diagram
Schematics set #2; 240 VAC in, 264 VAC out 3 phase 3 wire Open Delta:
Pictorial Diagram
1 Line Diagram
[This message has been edited by Scott35 (edited 09-26-2002).]