Can the EcoFlow DELTA Pro 3 start a 1/2 hp well pump?

Yes. The EcoFlow DELTA Pro 3 delivers 4,000 W continuous and 8,000 W peak; Well pump, 1/2 HP 115 V submersible (Franklin Electric 4-inch 2-wire motor 244504…G) draws about 1,000 W running and about 7,056 W when its motor starts. With everything else unplugged, one full charge runs it for roughly 3.5 h at that draw — about 1.7 days at 2 h a day.

Appliance running draw	1,000 W source (Maximum service-factor load 12.0 A / 1,000 W at 115 V; full-load rating is 10.0 A / 660 W. The higher figure is used.)
Appliance starting draw	7,056 W source
Continuous output ≥ running draw	Yes 4,000 W source
Peak output ≥ starting draw	Yes 8,000 W source
Usable energy	4,096 Wh × 0.85 = 3,482 Wh factor: see methodology
Runtime at running draw	3.5 h

Appliance running draw

1,000 W source (Maximum service-factor load 12.0 A / 1,000 W at 115 V; full-load rating is 10.0 A / 660 W. The higher figure is used.)

Appliance starting draw

7,056 W source

Continuous output ≥ running draw

Yes 4,000 W source

Peak output ≥ starting draw

Yes 8,000 W source

Usable energy

4,096 Wh × 0.85 = 3,482 Wh factor: see methodology

Runtime at running draw

3.5 h

Why the start, not the running load, decides it

This is the tightest yes on the site. The motor's running draw, 1,000 W at its maximum service-factor load, is 25 % of the DELTA Pro 3's 4,000 W continuous rating. Starting is a different matter. Franklin Electric's AIM manual lists 58.8 A locked-rotor current for the 115 V 1/2 hp two-wire motor. At 120 V that is 7,056 W, 88 % of EcoFlow's 8,000 W surge rating. Unlike most starting figures on this site, this one comes from the motor maker, not a generic chart. The margin is 944 W, and EcoFlow's page does not say how long the station can hold its surge. A motor draws locked-rotor current until it gets up to speed, typically a fraction of a second.

Everything else running counts against the margin

Sizing assumes the largest motor starts while everything else keeps running. With a top-freezer fridge running, the peak when the well pump starts is about 7,416 W, under the rating. Add a furnace blower and a 1/2 hp sump pump, and that peak becomes about 8,393 W, over it. In practice the fridge can share the station with the well pump, but a full set of household motors cannot.

Hours of pumping

EcoFlow publishes no runtime factor for this model, so the 0.85 default from the methodology applies:

hours = 4,096 Wh × 0.85 ÷ 1,000 W ≈ 3.5 h of motor running time.

At the motor's 660 W full-load rating, the same formula gives about 5.3 h. The pump runs only when the pressure switch calls for water, so how long a charge lasts on the calendar depends on household use. Divide 3,482 Wh by 1,000 W × the pump's daily running hours.

Wiring, voltage and conditions

A submersible well pump is normally wired through its pressure switch rather than plugged into an outlet. Connecting one to any portable source needs an inlet or transfer switch installed by an electrician. Franklin also builds this motor for 230 V (244505), which cannot run from a 120 V outlet. The DELTA Pro 3 does have 240 V outlets, but this page's figures cover only the 115 V motor, so check the nameplate. EcoFlow lists discharge from 14 to 113 °F and charging from 32 to 113 °F. It rates the cells for 4,000 cycles to 80 % of original capacity, at 77 °F per EcoFlow's FAQ.

Recharging

EcoFlow gives 0 to 80 % in 50 minutes on the wall (its page prints no AC input wattage) and up to 2,600 W of solar across two inputs. At 113.54 lb, this is a station you install, not one you carry.