What happens if the master stream nozzle is not shut down before charging?

When the master stream nozzle is not shut down before charging, water wastage may occur. This is primarily due to the fact that charging the system with the nozzle open allows water to flow out continuously without being directed towards a fire or target. Essentially, the firefighting system is being pressurized while the water is not effectively used, leading to unnecessary water loss.

In operational scenarios, it is crucial to ensure that all nozzles are properly secured before charging the fire suppression system. By doing so, water is conserved, and the pressurization process can be controlled to ensure timeliness and effectiveness in delivering water to the fire scene.

The other options, while related to system operation, do not accurately describe the immediate consequence of failing to shut down the nozzle before charging. For instance, while pressure dynamics and potential backflow may play roles in other situations, the primary concern in this context revolves around the wastage of water.