Final answer:
Transformers are marked with their voltage ratings to ensure safety and compatibility with electrical systems, as they are key in reducing high transmission voltages to safer levels for local use.
Step-by-step explanation:
Transformers that may be installed on systems of differing voltages are clearly marked with their input and output voltage ratings and other electrical characteristics. This information is crucial for ensuring compatibility with the electrical system they will be joining, and for maintaining electrical safety by preventing mismatches that could lead to overheating, fires, or other hazards.
Transformers play a key role in electrical safety systems by changing voltages to appropriate levels for different stages of power distribution. Electric power is generated and transmitted over long distances at high voltages to limit energy losses. Transformers are then used to step down the high voltages to safer, lower levels for local distribution and user sites. For example, in a power distribution system, voltages might be reduced from over 200 kV to 5-13 kV for neighborhoods or industrial areas, and then again to 120, 240, or 480 V for safety at individual user locations.