What Is Short Cycling?

Possible causes include a narrow level range, bad sensor, leaking check valve, high inflow, blocked pump, oversized pump, poor control settings, or a small usable wet-well volume. The motor and starter may not have enough time to cool.

Record the starts per hour, run time, level range, and inflow condition. Watch whether the wet well rises again immediately after shutdown. A leaking check valve may allow pumped water to flow backward and restart the cycle.

Do not widen level settings without checking the approved operating range. Higher levels can reduce storage for an emergency. Lower levels can create vortices or expose equipment. Find the cause before changing control points.

Track starts after the correction. A new setting may appear to help during low inflow but fail during the morning peak. Reviewing a full day or wet-weather cycle gives a better picture than watching one start and stop.