WEN GN400i (open-frame inverter, no CO sensor)

The GN400i is WEN's open-frame 4,000 W gasoline inverter. WEN's product page does not name a use case beyond its RV-ready TT-30R receptacle, and it never prints the model number in the text: “GN400i” appears in the page title and the 2019 manual. WEN also lists a GN400iM at a different price; it is not covered here. Compared with WEN's DF680iX, it runs on gasoline only, starts by recoil only, has no 240 V outlet and no CO sensor.

Running vs starting watts

WEN rates it at 3,500 running (“rated”) and 4,000 surge watts. The 4,000 W in the name is the surge figure, available only while a motor starts; continuous loads must fit under 3,500 W. On its own it can start a 7-1/4 in circular saw, a 1/2 HP sump pump or a French-door refrigerator. It cannot start our 1/2 HP well pump, whose starting figure is 7,056 W.

Run time

WEN publishes 7 hours at 50 % load on the 1.85-gallon tank (the product page says “over 7 hours of half-load run time”). That is the only published point; we do not extrapolate to other loads. It is an inverter generator, and WEN states total harmonic distortion under 0.3 % at no load and under 1.2 % at full load, the figure that matters for laptops, TVs and chargers.

Safety

Neither the product page nor the 2019 manual mentions a CO sensor, so nothing on this generator shuts it down if exhaust builds up. Placement is the only protection: CPSC says outdoors only, away from the house, never on a porch or in a carport, with the exhaust pointed away from buildings. Our CPSC recall search found no WEN generator recall.

Add your appliances to the calculator to check your own load against these figures.