At what point does a fire pump activate?

A fire pump activates when the pressure in the system drops below a predetermined threshold. This threshold is essential as it indicates that there is a demand for water flow, often due to the activation of fire sprinklers or other suppression systems. The pump provides the necessary boost in pressure to ensure that the water can effectively reach all parts of the system during a fire event, maintaining the efficiency and effectiveness of fire suppression efforts.

When the pressure falls below this set point, typically due to water being drawn by the system, the fire pump is designed to start automatically to restore system pressure and flow. This is a critical aspect of fire protection systems, as it ensures that adequate water supply is available when needed most.

Activation based solely on fire alarms or other components, such as the jockey pump disengaging, does not account for the dynamic pressure changes that occur during an incident, making pressure thresholds a more reliable activation criterion for fire pumps.