Ham Radio General Class Practice Test

Which situation requires that the main power be disconnected when using an emergency generator?

1. When connecting additional loads

2. When performing routine maintenance

3. When connecting to a parallel grid

4. When powering devices that use the same feed as utility lines

The correct answer is: When powering devices that use the same feed as utility lines

In situations where the main power must be disconnected while using an emergency generator, it is essential to prevent backfeeding into the utility lines. This occurs when powering devices that are tied to the same electrical feed as the utility lines. If the generator is connected to the system without disconnecting the main power, it can send electricity back into the grid, posing a significant hazard to utility workers who may be repairing downed lines, as well as creating potential damage to the generator and other equipment. This safety measure is critical to ensure a safe operation environment and to adhere to proper protocols. Disconnecting the main power before engaging the generator ensures that the emergency power source operates independently, completely isolating it from the utility supply. This understanding of power transfer and safety is fundamental for amateur radio operators and anyone working with emergency generators.