What occurs when an electrical or hydraulic release is activated in a preaction system?

When an electrical or hydraulic release is activated in a preaction system, water is allowed to enter the standpipe system. A preaction system is a type of sprinkler system that requires two events to occur before water is discharged, which enhances the system's reliability and minimizes accidental activations.

In this context, the activation serves as a signal that the fire protection system is ready to respond to a detected hazard. Once the release is activated, a valve opens to allow water to flow into the pipes of the standpipe system. This water is then available for immediate use by firefighters or occupants in the event of a fire.

This method helps ensure that the system is filled and ready to deliver water to the areas where it is needed while also preventing water damage that could occur if the system were to discharge unnecessarily. Other options do not reflect the primary function of the system at this activation stage.