WEN GN400i Open Frame Inverter Generator 4000W
- 4000 surge / 3500 rated watts
- 212cc 4-stroke OHV engine, CARB compliant
- 1.85 gallon tank, over 7 hours at half load
- Two 120V NEMA 5-20R, one TT-30R RV, two 5V USB
- Parallel ready with a kit sold separately
- 66.1 lb, 19.8 x 13.8 x 18.9 inches
- Two-year warranty
Last refreshed Sep 7, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
WEN built this open frame inverter for camping, RV hookups and home backup where clean power for electronics matters. The open frame leaves the engine exposed, and the listing gives no noise level.
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ASIN: B07XZVLC9HModel: GN400iCategory: Generators
Overview
WEN pairs a gas engine with an inverter that mimics a pure sine wave, so laptops, phones and TVs can run safely from it. An RV ready outlet joins standard household receptacles and USB ports on the panel.
Clean, steady power for sensitive electronics plus a direct RV plug make it versatile for campsites and outages. An eco mode trims fuel use at light loads.
Who it's for
Weekend campers, RV travelers and households wanting backup for fridges, lights and electronics get a portable inverter that plugs straight into a trailer. People needing heavy whole home output should look at a larger standby system.
Pros and cons
- Clean power safe for sensitive electronics
- RV ready TT-30R outlet
- USB ports on the panel
- Eco mode adjusts fuel use
- Parallel kit sold separately
- Open frame leaves the engine exposed
- Electric start not listed
- Noise level not listed
Performance notes
The inverter rebuilds the engine's output into a smooth wave, which is why harmonic distortion stays low enough for electronics. Eco mode lets engine speed follow the load, so run time depends heavily on how much is plugged in.
Specifications
| Brand | WEN |
|---|---|
| Model | GN400i |
| Dimensions & fit | |
| Item weight | 66.1 lb |
| Item Dimensions L x W x H | 19.8 x 13.8 x 18.9 inches |
| Capacity & performance | |
| Tank volume | 1.85 gallons |
| Power & efficiency | |
| Running Wattage | 3500 watts |
| Starting Wattage | 4000 watts |
| Fuel Type | Gasoline |
| Voltage | 120 volts |
| Total Power Outlets | 5 |
| Warranty & support | |
| Warranty Description | Two-year warranty |
| Other details | |
| Runtime | Over 7 hours at half load |
| Engine Type | 4-stroke OHV |
| Ignition System Type | Electronic |
| Number of Outlets | Two 120V NEMA 5-20R, one 120V TT-30R |
| Number Of Ports | Two 5V USB |
| Additional Features | Eco mode, parallel ready, low oil and low fuel shutdown, overload protection |
| Engine Displacement | 212 cc |
| Current Rating | 26.6 amps |
| Total harmonic distortion | Under 0.3 percent no load, under 1.2 percent full load |
Frequently asked questions
How do you maintain the WEN GN400i between uses?
The listing covers built-in safeguards: low oil and low fuel automatic shutdown, overload protection and indicator lights. It does not give a maintenance schedule, so follow the manual for oil changes and storage.
Can the WEN GN400i plug directly into an RV?
Yes. It has one 120V RV ready TT-30R receptacle.
Is the WEN GN400i safe for laptops and phones?
It is designed to mirror a pure sine wave, with harmonic distortion under 0.3 percent at no load and under 1.2 percent at full load.
Can two WEN GN400i generators be linked?
Yes, it is parallel ready with any WEN inverter generator, but the WEN Parallel Connection Kit is sold separately.
How long does the WEN GN400i run on a tank?
The 1.85 gallon tank gives over 7 hours at half load.