A Hammond wiring diagram shows primary and secondary winding configurations, tap leads, grounding points, and recommended connection schemes for different input and output voltages. It indicates terminal markings, phase relationships, and sometimes vector groups, enabling installers to configure series or parallel connections correctly. The diagram also highlights shielding, dual or multiple primaries/secondaries, and any connection precautions. This ensures safe installation, correct voltage outputs, and proper phasing in industrial panels or equipment.