The Wen GN400i is an open frame inverter generator with a peak power output of 4000W and 3500W running power. As one of the cheapest 4000W inverter generators, this review plans to reveal whether the Wen GN400i is worth buying. In doing so, we will provide a comparison between the Wen GN400i and similar inverter generators from other brands.
The Three generators we’ll be reviewing:
►Best Value Open Frame Generator / WEN GN400i
WEN GN400i : Exceptional value from WEN, who seems to continually find new ways to provide more value for less. It’s relatively quiet (67dB) and reliable. Go direct to article review.
- 4000W starting / 3500W running
- Outlets: 2X 120V NEMA 5-20R; 2X 5V USB; 1X 120V NEMA L5-30R (transfer switch ready)
- 50% quieter than standard gas models
- 2 year warranty
- Read customer reviews
FACTS : WEN sold more than 50-million consumer products during their first 50-years of operation. WEN was founded by Nick Anton in 1951.
►Contender / Generac GP3500iO
Generac GP3500iO : Marketed with terms like PowerRush and TruePower giving an impression that it’s unique, but in truth, it’s on par with the other two open frame generators we review. Overall, it’s a solid choice from a brand that’s been in business since 1959. Direct to review.
- 3500W starting / 3000W running
- Read customer reviews
FACT : Generac is currently owned by Briggs & Stratton.
►Best Quality / Westinghouse iGen4200
Westinghouse iGen4200 : More starting power, very well-made, and provides exceptional efficiency with 15 hours of run-time at 50% load. Wow! Overall, the best quality. Go direct to article review.
- 4200W starting / 3500W running
- 50% quieter than standard gas models
- 3 year warranty
- Read customer reviews
Quick Generator Comparison
The Wen GN400i is the cheapest of the three inverter generators that we’re reviewing here and compares well to the others in terms of spec level. It is, however, the only model that cannot be sold in California, this obviously means the Wen generator does not have the best emission levels.
The Generac provides the lowest running wattage of 3000W. The Wen and Westinghouse have a more impressive 3500 running watts. Peak or starting watts differ for all three generators. The Westinghouse iGen4200 has the highest peak power (4200W) and the Generac GP3500iO, the lowest (3500W). With the Wen GN400i in between at 4000W peak capacity.
As the most expensive of the three, the Westinghouse offers some extra specifications that may make it worth the higher price. It is the only generator in this review to offer GFCI protection for the 120V 20A outlets, making it the only OSHA compliant jobsite generator in this review. It is also the most fuel efficient, which may make up for the higher purchase price over time.
These are all inverter generators, with an economy mode and the option to use more than one generator in parallel. The Wen GN400i has a 2-year warranty, whereas the other two generators have a 3-year warranty. This may suggest a higher quality standard for the Generac and Westinghouse generators. Considering that the Wen generator should cost around 30 – 50% less than the others, it offers good value for money and is, by no means, a substandard product.
These are all American companies, which should put many buyers at ease. However, we can’t be certain how many components are manufactured in other countries. At least, you know quality control and final accountability, in terms of warranty and service, lies in the US.
WEN GN400i / Best Value Open Frame
- Power : 4000 starting watts / 3500 rated watts
- 50% quieter and 30% lighter than a typical 4000W generator
- 212cc 4-stroke OHV engine
- Can safely run sensitive devices : smartphones, tablets, televisions & computers
- Parallel ready panel : Double your power. Connect two models.
- OUTLETS : 2X 120V NEMA 5-20R receptacles, 2X 5V USB ports, 120V transfer-switch-ready NEMA L5-30R twist lock receptacle,
- Two-year warranty
Wen is based in Illinois. Since 1951, Wen has been producing affordable power equipment and has earned a reputation for great value and sound quality. This makes the Wen GN400i one of the best options if you’re looking for a cheap inverter generator. The reassurance of a reputable US brand behind you, should offer immense peace of mind.
Being an open, metal frame generator, one gets a sense of a more industrial-grade machine, opposed to the plastic enclosed inverter generators that have become the norm. While the open frame doesn’t offer the same sound insulation as enclosed inverter generators, the Wen GN400i isn’t a particularly noisy machine. At low power output (less than 25%), the Wen has a noise level reading of 67dBA.
Although the Wen engine does not meet California emission standards, it can compare well to the other generators in this review in most other aspects. This is a 212cc OHV, 4-stroke engine with a manual choke. It has an economy switch which allows the engine to run at lower RMP when the electricity demand is less than 25% of the rated output (<875W). I find it surprising that, despite being one of the cheapest inverter generators, the Wen GN400i has one of the lowest Total Harmonic Distortion (THD) Specifications – less than 1.2% at full load. Generally, inverter generators are rated at <3%THD. For a cheap machine, this is quite a remarkable inverter.
The 1.85-gallon gas tank holds sufficient fuel to keep the generator running for 7-hours at 50% rated load. This is a remarkable 6.6 kilowatt-hours per gallon. With one of the best fuel consumption rates, and an extremely reasonable purchase price, the Wen GN400i is a real winner when it comes to economy. The weight is also reasonable, at 66.1 pounds. Even though it has no wheel kit, the Wen isn’t too much hassle when it comes to portability. The wrap-around metal frame provides plenty of convenient positions to hold the generator, making it easy enough to carry.
The Wen GN400i has a very basic control panel. The choke and engine on/off switch are both mounted on the panel for easy access. It has 2 X 20A 120V outlets, a transfer switch ready 120V 30A outlet, and 2 X USB ports. No there is no digital (or analog) display for voltage and other system information. Only the standard LED warning lights are provided (low oil, fault, and system okay). It has all the basic safety features: a single 20A circuit breaker protects the 20A outlets from current overload. If the total load exceeds the rated 33.3 peak amps, or a longer overload situation more than the peak running capacity of 29A, the generator will shut down and will need to be restarted. Not the most convenient way of doing things but, at least the generator won’t sustain any damage from an overload or short circuit. It also has low oil shutdown and a spark arrestor.
Instead offering a bunch of bells and whistles, the Wen GN400i offers the basics at a wonderfully affordable price. Costs have been cut on extras, like a digital display and electric starter. Though a main circuit breaker would be nice for more convenience, this does save a few dollars without compromising on the quality of essential components. The guys at Wen have clearly applied common sense when trying to reduce costs without sacrificing on the general integrity of the machine. They’ve ended up with a fine product that probably offers the best value for money.
Top Contender : Open Frame Model : 3500W start / 3000W run
- PowerRush Advanced Technology = 50% more starting capacity
- 50% Quieter than traditional gas models
- 8 hour Run Time at 50% Rated Load
- 11 hour Run Time at 25% of Rated Load
- 25% Lighter reduces fatigue and improves portability*
- True Power is their term for clean, stable power
- PowerDial Choke, Run, Off : Three operation settings
- Economy Mode automatically adjusts engine speeds
- USB Ports charge mobile devices including smart phones and tablets
- Double the power by running two in Parallel
Generac started producing generators in 1959 and has remained solely dedicated to this market. They only make generators, ranging from small portable units, up to large industrial scale standby generators, up to 9 megawatts. Generac products are generally considered to be of a high quality standard, whilst also being an affordable option for home and recreational generator buyers.
The Generac GP3500iO is an open frame, inverter generator with a peak power capacity (starting watts) of 3500W and a rated running load of 3000W. Whilst more expensive than Wen GN400i, this is probably the closest rival to the Wen model, alongside the Champion equivalent. These three generators rank amongst the most affordable 4KW inverter generators.
Generac has trademarked a host of fancy titles, like PowerRush technology, TruePower, and more. It is, however, no different to any other inverter generator in the same class. In fact, it has a lower peak output (by 500W) when compared to the Wen GN400i. It has the expected economy mode, operated by a switch on the user panel.
The 212cc OHV engine seems to be on a par, when compared to the other two generators in this review. Fuel economy is nowhere nearly as impressive as the Wen generator. The Generac GP3500iO has a larger gas tank, holding 2.37 gallons. This provides 8-hours runtime at 50% load, an hour more than the Wen GN400i. However, this does not mean improved fuel consumption, this is purely a result of the larger gas tank. The Generac produces 5 kilowatt-hours per gallon, making it about 25% less fuel efficient compared to the Wen GN400i.
Generac have done a great job when designing the user panel. It has, what they call a PowerDial, which is simply a dial that allows you to switch the generator on, open the fuel supply, and engage the choke with a single dial. This does make things simpler and they’ve place the recoil starter on the panel next to this dial. It’s a hassle-free machine to start. Like the Wen generator, this one has no electric starter.
It has the expected array of outlets, 2 X 120V 20A household outlets, and a twist lock 30A 120V outlet. A 20A circuit breaker protects both 20A outlets and the 30A outlet has an independent 30A breaker. However, this 30A breaker is only of importance when using two generators in parallel, as a single GP3500iO has a peak power output of 25A. The main breaker fitted to the generator is rated at 25A so, when using a single generator, the main breaker will trip before the dedicated 30A breaker will. You also get 2 X USB ports, a digital hour meter and all the normal warning lights.
- 4,200 Peak Watts, 3,500 Running Watts
- RV and Camper Ready with 120V 30A Outlet (TT-30R)
- Fuel Efficient – Up to 18 Hour Run Time (2.6 gal)
- Super Quiet – Less Noise than Traditional Portable Generator
- Safe for Sensitive Electronics – Inverter Technology (<3% THD)
- Very Portable – Only 82 lbs
- 3-Year Warranty and Lifetime Technical Support
Although the Westinghouse iGen4200 can end up costing about $200 more than the Wen GN400i, I prefer the Westinghouse generator. Though many may not feel the higher price is justified. Westinghouse has only been in the portable generator business since 2011. But the company is far older than either Wen or Generac. Westinghouse Electric company was responsible for building some of the first industrial and commercial power plants in the US, dating back to the late 1800s.
One of the reasons I rate Westinghouse generators so highly is the incredible engines that they use. The iGen4200 may be more expensive than the Wen GN400i but, in the general scheme of things, this is not a particularly expensive generator. Yet it can rank alongside some the very best, most expensive inverter generators. The 212cc OHV Westinghouse engine appears to be very similar to the others. That is until you look at the almost unbelievable fuel economy.
The iGen4200 is fitted with a 2.6 gallon metal gas tank. The slightly larger gas tank, combined with an incredible 10 kilowatt-hour per gallon fuel consumption, offers an astounding 15-hours runtime at 50% load. Being able to run the generator for such a long time between refills is really convenient. Furthermore, you’ll end up saving around 40% on fuel bills, when compared to the Wen GN400i. In the long run, the Westinghouse will probably be the most economical. It shouldn’t take long to make up the ± $200 price difference in gas savings. I think the Westinghouse iGen4200 may be the most fuel efficient gas generator ever built. This is also a robust engine with top emission standards and is CARB compliant.
The control panel and user functions offer a little more than the other two generators. For RV use, this is the most convenient, as it has a TT-30R 120V 30A RV outlet. It’s also the best 4KW inverter generator for contractors, thanks to GFCI protection for the two 120V 20A (5-20R) outlets. The 20A and 30A circuits are have push to reset circuit breakers for each circuit. The Westinghouse iGen4200 has a comprehensive VFT digital meter, displaying voltage, frequency, and total runtime.
The Westinghouse iGen4200 is a truly accomplished inverter generator, easily capable of competing in the big leagues. This makes the price tag very reasonable, for the caliber of generator that you’re buying. Of the generators reviewed here, it is the most powerful in terms of peak power output, which gives it a slight advantage. The most advantageous aspect to this generator has to be the mighty impressive fuel economy, which will easily offset the slightly higher purchase price.
- WEN pioneered random orbital technology, now commonly used for polishers and random orbital sanders.
- Generac was founded by Robert Kern in 1959 and is now a Fortune 1000 US manufacturer
- From 1992 – 1996, Generac engaged in a private labeling agreement with Caterpillar (CAT).
- George Westinghouse founded the Westinghouse Electric Corporation in 1886 and was renamed the Westinghouse Electric Company in 1945
- Westinghouse built the first steam turbine electric plant in the US at Hartford Electric Light Co in 1901.
- Westinghouse was a major contributor to the development of nuclear power generation