The VP-1000 pumps in the Healy EVR Phase system run at full speed only when?

The correct response relates directly to the operational design of the Healy EVR Phase system, particularly how the VP-1000 pumps are engineered to maximize efficiency and safety during vapor recovery. The pumps are activated to run at full speed only when nozzles on both sides of the dispenser are authorized and off the dispensers. This configuration indicates that the system is ready to handle fuel delivery while ensuring that vapor recovery is optimized from both sides, effectively managing any vapor displaced in the fuel delivery process.

By having both nozzles off the dispensers, it allows the system to manage the potential vapor release that occurs when fuel is dispensed. This design helps in effectively preventing any unnecessary emissions while maintaining an efficient flow rate of the pumping system. Running the pumps at full speed under these conditions ensures that vapor recovery is maximized when both nozzles are in operation and allows the system to respond to demand without delays caused by vapor management measures.

In contrast, the other choices involve scenarios where either one side is authorized, or when dispensers are authorized but not dispensing gas, which does not necessitate the pumps running at full speed. These situations do not meet the operational criteria for maximizing vapor recovery and efficiency.