For interconnected electric power production sources, where the power source output connection is made to a feeder, the ampacity of the feeder must be greater than or equal to ___ the power source output circuit current.

For interconnected electric power production sources, where the power source output connection is made to a feeder, the ampacity of the feeder must be greater than or equal to ___ the power source output circuit current.

• A. 25%
• B. 100%
• C. 125%
• D. 175%

Answer: (C)

When a power production source is interconnected to a feeder, treat the source’s output as a continuous current that can flow into the feeder for long periods. To prevent overheating and provide a margin for backfeed and protection coordination, the feeder’s ampacity must be sized larger than the source current. The standard practice is to set the feeder ampacity to at least 125% of the power source’s output current. This extra 25% accounts for continuous operation and potential backfeed conditions, ensuring the conductor remains within its temperature rating. So the required sizing is 125% of the source output current.

When a power production source is interconnected to a feeder, treat the source’s output as a continuous current that can flow into the feeder for long periods. To prevent overheating and provide a margin for backfeed and protection coordination, the feeder’s ampacity must be sized larger than the source current. The standard practice is to set the feeder ampacity to at least 125% of the power source’s output current. This extra 25% accounts for continuous operation and potential backfeed conditions, ensuring the conductor remains within its temperature rating. So the required sizing is 125% of the source output current.