Lift Station Runtime & Backup Power Calculator - Pump Cycles, Backup Power & Overflow Time
Size generators and calculate time to overflow for any lift station
Check pump cycles per day, lead pump runtime, backup-power load, local generator kW calculator, fuel runtime, and wet-well overflow time for wastewater lift-station planning. Enter daily flow, active wet-well volume, pump rate, motor HP, fuel tank size, and auxiliary load to see the simple arithmetic and the source gaps that must be reconciled before design, equipment, safety, or compliance use.
Check pump energy prompts before comparing backup-power and maintenance options
Pump Energy Cost Calculator →Check downstream sludge assumptions after collection-system flow facts are checked
Sludge Production & Disposal Cost Calculator →Check force-main friction before comparing the app pump rate to actual TDH
Pipe Pressure Drop Calculator →Run a separate generator load screen before supplier and electrical review
Generator Sizing Calculator →How It Works
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Enter Station Configuration
Input average daily flow (GPD), wet well active volume (gallons between lead-on and lead-off levels), pump flow rate (GPM), and number of pumps.
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Enter Pump and Motor Data
Input pump HP for the local load calculator. Then verify motor nameplate, starting method, pump curve, and actual TDH separately.
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Configure Backup Power
Enter fuel tank size, auxiliary load, motor efficiency, and either a manual generator rating or the local auto-screen option.
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Review Overflow and Source Gaps
Compare average and peak overflow time, then reconcile alarms, response, bypass pumping, fuel logistics, permit, and qualified-review requirements.
Built For
- Collection system operators screening outage storage and alarm-response assumptions
- Public works teams comparing local backup-power load and fuel-runtime inputs before supplier review
- Engineers preparing preliminary lift-station planning checks before full hydraulic and electrical design
- Emergency planners reconciling response-time, bypass-pumping, and reporting assumptions
- Operators tracking pump cycles as a maintenance and investigation flag
Assumptions
- Average daily flow is assumed constant and evenly distributed over 24 hours for baseline pump cycle calculations
- Wet well active volume is the usable volume between lead-on and lead-off level setpoints
- Pump capacity is at the rated duty point and does not account for impeller wear, clogging, or system curve shifts
- Generator load screen uses a local 6x starting multiplier and a 1.25 running-load comparison
- Fuel consumption auto-estimate uses a local 0.07 gallons per hour per effective generator kW diesel calculator
- Overflow time is calculated from entered active wet-well volume only, not rim elevation, invert elevation, or upstream storage
Limitations
- Does not model inflow and infiltration (I/I), diurnal peaks, upstream storage, or current wet-well level at outage start
- Pump cycling calculations assume constant inflow and simple on/off control
- Generator load analysis is simplified and does not account for soft starters, VFDs, reduced-voltage starting methods, voltage dip, ATS sequence, or generator transient capability
- Does not evaluate force main hydraulics (friction loss, air release, surge protection) that affect actual pump discharge rate
- Overflow screen does not account for emergency bypass pumping, tanker response, alarms, notification cascade, or spill reporting rules
- Does not calculate SCADA alarm setpoints, telemetry requirements, NEC/AHJ requirements, NFPA 110 classification, or fuel-quality maintenance
References
- TEN-STATES-WASTEWATER-2014-SOURCE - Recommended Standards for Wastewater Facilities source pointer
- WEF-MOP8-7TH-SOURCE - WEF MOP 8 design-reference pointer
- NFPA-110-2025-EPSS-SOURCE - Emergency and standby power systems source pointer
- NEMA-MOTORS-GENERATORS-SOURCE - Motors and generators source pointer
- CRANE-TP410-2022-SOURCE - Pump, pipe, valve, and fitting flow-reference pointer
- NIST-SP811-B8 - Unit conversion source pointer