Utilities make up the connections on the line side and load side of their transformers according to the NESC requirements.
What are these requirements
Utilities typically make connections on the line side and load side of their transformers according to the National Electrical Code (NEC) requirements or standards established by relevant regulatory bodies.
The National Electrical Code (NEC) provides guidelines, rules, and safety standards for electrical installations in the United States.
It outlines specific requirements and best practices for electrical wiring, equipment, and installations, including guidelines for connections on the line side (primary side) and load side (secondary side) of transformers.