When does a jockey pump activate in a sprinkler system?

A jockey pump is a small pump within a sprinkler system that serves a vital role in maintaining system pressure. It activates when there is a slight drop in pressure in the sprinkler system, ensuring that the system remains pressurized and ready for use. This helps to prevent the main pump from cycling too frequently, which can lead to wear and tear.

In many designs, a jockey pump is set to kick in when the system pressure falls below a certain threshold, which might occur due to minor leaks, evaporation, or normal operation of sprinklers. By quickly restoring pressure, the jockey pump helps to avoid false alarms that can occur when the pressure drops slightly.

On the other hand, significant leaks would typically require the main fire pump to engage, while scenarios such as the system being inoperable or alarms being triggered indicate larger issues that would not involve the jockey pump's function directly. Thus, the correct activation condition for a jockey pump is indeed a slight drop in pressure, allowing it to maintain the system's operational readiness effectively.