Underground transformers typically come in ____ configurations.

• A. 4
• B. 2
• C. 3
• D. 5

Answer: (C)

Underground transformers are typically built in three configurations because that covers the main ways power is delivered underground. You have single-phase units for serving individual customers or single-phase drops, three-phase units for feeding a three-phase underground feeder, and banked configurations where multiple transformers are used together to form a three-phase bank for larger or modular underground networks. This standard trio matches common distribution layouts and is why three configurations are considered the typical count.