- Wattage (Gas): 4,500 W / 3,650 W
- THD: < 3%
- Noise Level: 69 dBA
- Fuel Type: Gasoline
- RV Ready: No
- Run Time@ 25% load: 25 h
- Run Time@ 50% load: Unspecified
- Weight: 106 lbs
Table Of Contents
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Description
The Firman W03661OF has a 208cc OHV 4-stroke engine that runs on gasoline and puts out 120V and 3,650W while running and 4,500W at its most powerful. Also, since the generator can work in parallel (but doesn’t come with a parallel kit), it can be linked to a second unit to make more power. The inverter generator has a noise level of 69 dBA, which is less than an office. It is started with a pull-start mechanism. The W03661OF can run for up to 25 hours on a full tank of fuel, which is 6 gallons (fuel consumption is approximately 0.24 GPH). As the W03661OF makes a clean sine wave with a Total Harmonic Distortion (THD) of less than 3%, you can safely plug sensitive electronics into the AC outlets.
Outlets
On the control panel, there are 4 AC outlets for: Duplex 120V 20A (5-20R); 120V 30A (L5-30R) receptacle; 120V 50A (14-50R) receptacle. It also has 3 DC outlets: two 5V USB ports (USB-A) that make it easy to charge devices like cell phones or tablets, and a 12V 8A receptacle that looks like a cigarette lighter that makes it easy to charge your batteries. Since it has a 14-50R outlet, this Firman unit is ready for an RV with a 50-amp service if you have an RV with 50-amp service. With the L5-30P to TT-30R adaptor that comes with it, the L5-30R plug can also be used to connect a simple RV. Note that the 14-50R outlet usually works with 120/240V. But this unit doesn’t give off 240V. This outlet is here for your convenience, but only 120V appliances should be plugged into it. Also, since the generator can only run at a maximum of 3650 watts, you won’t be able to use all 50 amps from the outlet.
Features
The status and activity of the W03661OF can be easily checked on the control panel, which has a meter that shows voltage, frequency, and lifetime hours. In addition to this information, the lights will let you know when the oil level is too low, the generator is overloaded, and the generator is ready. The inverter generator has a built-in fuel gauge that makes it quick, easy, and convenient to check how much gas it has. For safety, the generator has an automatic low oil shut-off and an overload protection (circuit breaker), so you can use it without worrying. The W03661OF also has Firman’s CO Alert carbon monoxide shutdown, which turns off the engine automatically when harmful levels of carbon monoxide build up around the generator or when a CO Alert fault happens. It’s a nice extra safety measure, but don’t forget to take your generator outside at all times. The Firman W03661OF comes with basic instructions and an owner’s manual to help you start the generator quickly. It also comes with a funnel, battery charging cables, a tool kit, oil, and an RV adapter.
Mobility
The Firman W03661OF is a standard, open-frame generator with dimensions of L24.5 x W24.1 x H23 in, This gives the generator stability and lets it be raised above ground level. The device was made to work well in harsh conditions and in the great outdoors. Even though this generator is technically “portable” in the sense that it can be moved, it is very hard to move by hand because it weighs 106 pounds. Still, once it’s on the ground, its 9″ wheels and foldable handle make it easy to move.
Product Videos
We could find any videos of the product at the time of writing. Please search YouTube for any update.
The following charts show how some of the most important features of the Firman-W03661OF compare to other generators with the same power output.
**Fuel efficiency is give in relative percentage, 0 being the lowest and 1 being the highest value. Please see below specification table for actual value.
Specifications
Generic
| Inverter | Yes |
| Fuel efficiency | 0.188 gal/kWh |
| Parallel capable | Yes, cable not included |
| RV ready | No |
| Fuel | Gasoline |
| Engine | 208 cc OHV 4-stroke |
| Starting system | Recoil |
| Voltage | AC: 120V 60 Hz, DC: 12V |
Power
| Gasoline | Propane | |
| Running watts | 3,650 W | n/a |
| Starting watts | 4,500 W | n/a |
| Running amps (@120/240V) | 30.4 amps | n/a |
| Peak amps (@120/240V) | 37.5 amps | n/a |
| Run time @50% load | Unspecified | n/a |
| Run time @25% load | 25 h | n/a |
Control Panel
| GFCI outlets | No |
| Covered outlets | Yes |
| Automatic Voltage Regulator | Inverter |
| AC outlets | 1x Duplex 120V 20A (5-20R); 1x 120V 30A (L5-30R); 1x 120V 50A (14-50R) |
| DC outlets | 2x 5V USB port (USB-A); 1x 12V 8A (cigarette lighter style) |
| Data center | VFT |
| Indicators | Low oil, overload and output ready |
| Fuel tank | Steel, 6 gal |
| Fuel gauge | Yes |
Mixed
| Weight | 106 lbs |
| Approx. dimen. (L x W x H) | 24.5 x 24.1 x 23 in |
| Noise (lower limit) | 69 dBA |
| THD | < 3% |
| Compliance | CARB, EPA |
| Security | Low oil and overload protection, CO monitoring |
| Spark arrestor | Yes |
| Accessories included | Oil, funnel, tool kit, RV adapter, battery charging cables, and wheel kit |
| Warranty | 3 years |
- We compared more than 500 portable generators at 50% load. We found that there is “skewed right” distribution for the difference between 50% load and 25% load and the median comes at 1.43. With this number we converter all the 25% load runtime to 50% load. Same with the propane efficiency, where median is 1.38.
- For some generators where propane runtime was not given, we used NIST 1994 GGE (Gasoline Gallon Equivalent) formula: 5.66 lbs. of propane = 1 gal of gasoline. All propane runtime is for 20 lbs. propane tank (4.7 gallons).
- Unlike many other sites, we actually tried to find out information about each of the above requirements. However, we are human and are therefore capable of the odd oversight or mistake. Please let us know if you spot any missing or erroneous values so that we can fix them.
About the Manufacturer
Firman Power Equipment is a business with a recent but reputable history in the power equipment sector. It was founded in 1999. The Arizona-based business provides a vast array of goods, including power tools, automotive equipment, storage items, work clothing, but its assortment of generators of different shapes, sizes, and outputs stands out above the rest. Interestingly, Firman serves as a de facto distributor of China National Machinery Industry Corporation’s goods in the US and is a fully owned subsidiary of that business.
Warranty Information
A warranty covers the Firman W03661OF for up to 3 years. This warranty may not cover all parts of the generator or may only cover certain parts. Check out Firman’s warranty policies if you want to know more about the warranty on a Firman generator. You can also call their customer service line at 1-844-FIRMAN1 (844-347-6261). Check Firman Website for more information.
