For interconnected electric power production sources, when a phase opens, the output shall be automatically disconnected from all ungrounded conductors. Which side of the protection equipment should the output connect to?

For interconnected electric power production sources, when a phase opens, the output shall be automatically disconnected from all ungrounded conductors. Which side of the protection equipment should the output connect to?

• A. Input side
• B. Supply side
• C. Load side
• D. Neutral side

Answer: (B)

The key idea is that protective devices in interconnected power sources must isolate the source from the rest of the system when something goes wrong. When a phase opens, the output of the power production source should be connected to the protection equipment on the supply side. This placement means that if the protection device trips, it interrupts the path from the generator to the ungrounded conductors, effectively disconnecting the source from the grid and preventing backfeeding. The neutral isn’t switched in this scenario, and the protection action is focused on stopping the flow from the supply side to the lines. That’s why the output is connected to the supply side.

The key idea is that protective devices in interconnected power sources must isolate the source from the rest of the system when something goes wrong. When a phase opens, the output of the power production source should be connected to the protection equipment on the supply side. This placement means that if the protection device trips, it interrupts the path from the generator to the ungrounded conductors, effectively disconnecting the source from the grid and preventing backfeeding. The neutral isn’t switched in this scenario, and the protection action is focused on stopping the flow from the supply side to the lines. That’s why the output is connected to the supply side.