A typical 1/2 to 3/4 HP submersible well pump draws about 1,000 watts while running (roughly 670-1,600 W from 1/2 to 1 HP). It needs a big starting surge, about 2,100 W for 1/2 HP and more for larger pumps.
- Running watts
- 1,000 WTypical; 670–1,600 W across models
- Starting watts
- 2,100 WGenerac lists about 2,100 W to start a 1/2 HP well pump; 3/4-1 HP…
- Per day
- 1.5 kWh1.5 h of use
- Current
- 4.2 AAt 240 V while running
Figures checked against DOE, ENERGY STAR and manufacturer data on . Your model's label is the final word.
Watts by model and setting
Most well pump models draw between 670 and 1,600 W while running; a typical one draws about 1,000 W. Assumes the pump runs about 1.5 hours a day in total to supply a household; 1,000 W x 1.5 h = 1.5 kWh. Actual run time depends on water use, well depth and pressure tank size.
- Horsepower: Franklin Electric's data shows about 670 W (1/2 HP) to 1,210 W (1 HP) at full load, rising to 960-1,600 W at service-factor load
- Well depth and pressure setting determine how hard the motor works
- 2-wire motors (no control box) have higher locked-rotor current than 3-wire motors
- Pressure tank size affects how often the pump cycles on and off
- Most US submersible pumps are wired for 240 V; some 1/2 HP models are 115 V
Running a well pump on backup power
This is a 240 V appliance. It needs a generator with a 240 V outlet or a transfer switch or interlock installed by a licensed electrician; most portable power stations only supply 120 V.
- Well pumps have one of the hardest starts in a home: Franklin Electric's minimum generator sizes are 2 kW (1/2 HP), 3 kW (3/4 HP) and 4 kW (1 HP) for externally regulated generators, 50% higher for 2-wire motors
- Most well pumps are 240 V and hardwired, so you need a generator with a 240 V outlet and a transfer switch or interlock installed by an electrician; never backfeed
- Only large power stations with 240 V output and high surge ratings can start a well pump; check surge watts and voltage before buying
- Run a gas generator outdoors only, at least 20 feet from doors, windows and vents; carbon monoxide from generators kills. Use heavy-duty extension cords or a professionally installed transfer switch, never backfeed a home outlet.
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Questions people ask
What size generator do I need to run a well pump?
Franklin Electric, a major submersible motor maker, lists minimum generator ratings of about 2 kW for a 1/2 HP pump, 3 kW for 3/4 HP and 4 kW for 1 HP (50% more for 2-wire motors). Add your other loads on top.
Can a portable power station run a well pump?
Usually only a large one with 240 V output and a high surge rating. Many 120 V power stations cannot start a 240 V submersible pump at all.
How many watts does a 1 HP well pump use?
Franklin Electric's data for 1 HP 230 V single-phase motors shows about 1,210 W at full load and up to about 1,600 W at service-factor load.