A wastewater lift station lives or dies by its pump controls. Get the configuration right and the station runs for years with minimal intervention; get it wrong and you risk short-cycling pumps, uneven wear, nuisance alarms, or — worst case — a sanitary sewer overflow (SSO). This guide walks through how to size and configure a lift station pump controller.
Start with the number of pumps
The "-plex" in duplex, triplex, and quadplex simply refers to how many pumps the station runs:
- Duplex (2 pumps) — the most common small-station setup: one lead, one lag/standby.
- Triplex (3 pumps) — adds capacity and redundancy for medium flows.
- Quadplex (4 pumps) — high-capacity stations where staged pumping matches variable inflow.
Alternation keeps wear even
Pump alternation rotates which pump starts first on each cycle so run-time is shared evenly across the station. Even wear means pumps and seals last longer and fewer fail unexpectedly. A good controller logs run-time per pump and can alternate on a fixed schedule or by accumulated hours.
Level sensing and set points
Most stations use a submersible level transducer (with float switches as backup) to drive lead, lag, and high/low-level set points. The controller starts the lead pump at the lead set point, brings on lag pumps as the wet-well continues to fill, and shuts down at the off set point — with a high-level alarm above all of them.
Alarms and remote notification
Local alarms protect the station; remote alarms (via cellular, radio, or SCADA) protect the operator’s weekend. Notifying staff the moment a fault occurs is the single most effective way to prevent an SSO.
- High and low wet-well level
- Pump fault / thermal / seal-fail
- Power loss and phase monitoring
- Communication or telemetry loss
Right-size the controller, not just the pumps
Radiant Control Systems builds flexible I/O–based lift station controllers that deliver lead-lag alternation, run-time logging, condition monitoring, and local/remote alarms — for duplex, triplex, or quadplex stations — at the cost of hundreds, not thousands. We serve municipal water and wastewater clients across Georgia and the Southeast.