Generators for Well Pumps and Sump Pumps

Why these two loads matter more than their size suggests

A well pump and a sump pump don't draw much power while running, but both have a real quirk that trips up sizing if it's ignored: motors like these need a surge of power, often several times their running wattage, for a moment when they first start. A generator sized only for the pump's steady running wattage can stall or fail to start it. This is a standard part of a proper load calculation, not a reason to avoid electric pumps.

Why sump pumps specifically matter for storm prep

A sump pump is often most critical during the exact kind of severe weather that also causes power outages, heavy rain and flooding risk rising at the same time the grid is more likely to go down. If a sump pump failing during an outage would mean real water damage, it belongs on the explicit list of circuits you tell your installer must be backed up, not assumed as automatically included.

What to tell your installer

• That you have a well pump and/or sump pump, and their horsepower or nameplate rating if you know it.
• Whether losing either one during an outage is a minor inconvenience or a real risk (flooding, no water pressure for a household that relies on well water).
• Any other major motor-driven loads, similar surge behavior applies to things like a central air compressor.

This kind of detail is exactly what a load calculation is for, and it's why the sizing calculator on this site treats these as loads to flag, not something to guess at.