Which type of flow alarm is designed to function without electricity?

The water motor alarm is specifically designed to operate without the need for electrical power, making it an essential component in certain plumbing systems where reliable operation is critical even during power outages. This alarm mechanism uses the flow of water to activate an internal motor, which then generates an audible alarm sound.

When water flows through the system, it actuates the motor within the alarm, which can be designed to operate solely based on the hydraulic force of the moving water. This ensures that even in scenarios where electrical systems may fail, the alarm can still function to alert occupants or operators about water flow conditions, such as leaks or overflows.

In contrast, options like the electrical alarm require a power source to operate, and the vane type and pressure type alarms, while they may have some mechanisms that do not rely entirely on electricity, typically incorporate electronic components or electric actuators in their functioning. Therefore, understanding the operation of each type of alarm highlights why the water motor alarm is the correct choice for a system requiring functional reliability independent of electricity.