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| Specification | Cummins Onan P9500df | Firman WT05571 |
|---|---|---|
| General | ||
| Product type | Generator | Generator |
| Fuel | Dual-Fuel | Tri-Fuel |
| Inverter | No | Yes |
| Parallel capable | No | Yes |
| RV ready | No | Yes |
| Running watts | Winner: Winner: 7500 W | 5500 W |
| Starting watts | Winner: Winner: 9500 W | 6850 W |
| Noise (lower limit) | 74 dB | Winner: Winner: 67 dB |
| Weight | 194 lbs | Winner: Winner: 131.4 lbs |
| Run time @50% load | Winner: Winner: 11 h | Not available |
| Run time @25% load | 16 h | 14.5 h |
| Fuel tank | 6.6 gal | 5.3 gal |
| Fuel gauge | Yes | Yes |
| Approx. dimensions (L × W × H) | 27.3 x 26.3 x 26.3 | 27.6 x 21.3 x 22.6 |
| Electrical | ||
| Voltage (AC) | 120/240 | 120/240 |
| Voltage (DC) | Not available | 12 |
| GFCI outlets | Yes | Yes |
| Covered outlets | Yes | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | 23 % | 3 % |
| Engine | ||
| Engine | 420 cc Ducar OHV 4-stroke | 322 cc OHV 4-stroke, cast iron sleeve. |
| Alternator | Not available | Not available |
| Starting system | Recoil, Electric, Remote | Recoil, Electric |
| Warranty | ||
| Warranty | 3 years | 3 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 7500 W | 5500 W |
| Starting watts | 9500 W | 6850 W |
| Running amps (120V) | Not available | Not available |
| Running amps (240V) | Not available | Not available |
| Peak amps (120V) | Not available | Not available |
| Peak amps (240V) | Not available | Not available |
| Run time @50% load | 11 h | Not available |
| Run time @25% load | 16 h | 14.5 h |
| Propane | Not available | Not available |
| Running watts | 6750 W | 5000 W |
| Starting watts | 8550 W | 6250 W |
| Running amps (120V) | Not available | Not available |
| Running amps (240V) | Not available | Not available |
| Peak amps (120V) | Not available | Not available |
| Peak amps (240V) | Not available | Not available |
| Run time @50% load | Not available | Not available |
| Run time @25% load | 8 h | 9.5 h |
| Natural gas | Not available | Not available |
| Running watts | Not available | 4500 W |
| Starting watts | Not available | 5500 W |
| Running amps (120V) | Not available | Not available |
| Running amps (240V) | Not available | Not available |
| Peak amps (120V) | Not available | Not available |
| Peak amps (240V) | Not available | Not available |
| Run time @50% load | Not available | Not available |
| Run time @25% load | Not available | Not available |
| Other | ||
| Data center | Not available | Not available |
| Indicators | false | Not available |
| Compliance | EPA | EPA, ANSI/PGMA G300-2023 |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | true | Bonded to frame |
| UPC | 690781007932 | 840876155714 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 7500 | 5500 |
| Running Watts (Propane) | 6750 | 5000 |
| Running Watts (Natural Gas) | Not available | 4500 |
| Starting Watts (Gasoline) | 9500 | 6850 |
| Starting Watts (Propane) | 8550 | 6250 |
| Starting Watts (Natural Gas) | Not available | 5500 |
| Runtime @ 50% Load (Gasoline) | 11 | Not available |
| Runtime @ 25% Load (Gasoline) | 16 | 14.5 |
| Runtime @ 25% Load (Propane) | 8 | 9.5 |
| AC Outlet Types | 2x Duplex 120V 20A (5-20R); 1x 120/240V 30A (L14-30R) | 1x Duplex 120V 20A (5-20R) GFCI; 1x 120V 30A (TT-30R); 1x 120/240V 30A (L14-30R); 1x 120/240V 50A (14-50R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | Ducar OHV 4-stroke | OHV 4-stroke |
| Engine Displacement | 420 | 322 |
| Cylinder Sleeve | Not available | cast iron sleeve |
| Engine Oil Type | SAE 10W-30 | Not available |
| Runtime & fuel system | ||
| Runtime @ 25% Load (Gasoline) | 16 | 14.5 |
| Runtime @ 50% Load (Gasoline) | 11 | Not available |
| Safety & compliance | ||
| Overload Protection System | Low oil and overload protection | Low oil and overload protection, CO monitoring |
| Low Oil Protection | Yes | Yes |
| Carbon Monoxide Monitoring | Yes | Yes |
| Included equipment | ||
| Starting Components | Not available | Oil, funnel, tool kit, propane hose, and battery |
| Included Accessories | Oil, funnel, tool kit, key fob, battery charger, propane hose, battery, and wheel kit | Oil, funnel, tool kit, propane hose, and battery |
| Warranty & identification | ||
| Commercial Warranty | 3 | 3 |
| Part Number | A074Z438 | Not available |
| Additional specs | ||
| Summary | The Cummins Onan P9500df is a 7500-watt dual-fuel generator built for users who need sustained power across multiple scenarios. Running on either gasoline or propane, it delivers 9500 peak watts, enough to start large air conditioning units or power multiple job site tools simultaneously. The dual-fuel architecture means users can switch between fuel sources based on availability and storage constraints. Propane tanks store longer without degradation, while gasoline offers wider accessibility. This flexibility makes the unit valuable for both seasonal backup power and year-round work environments.
The 194-pound weight and 27.3 x 26.3 x 26.3 inch footprint define this as a semi-portable unit. The included wheel kit enables movement across job sites or between storage locations, but this is not a grab-and-go machine. Users planning frequent relocation should factor in the logistical demands. The three-year commercial warranty covers manufacturing defects, giving buyers defined ownership support across the critical early-use period. | The Firman WT05571 is a 5,500-watt tri-fuel generator that runs on gasoline, propane, or natural gas. On gasoline, it delivers 6,850 starting watts and 5,500 running watts, enough to power a full home electrical panel during an outage or run multiple job site tools simultaneously. On propane, output drops to 6,250 starting and 5,000 running watts. On natural gas, it falls to 5,500 starting and 4,500 running watts. This fuel flexibility means users can switch between sources based on availability, cost, or storage preference without buying multiple generators.
The tri-fuel capability makes this unit valuable for homeowners in regions with natural gas infrastructure, RV owners who can refill propane at any campground, and contractors who need to adapt to job site fuel availability. The 3 percent THD rating protects laptops, televisions, and other sensitive electronics from voltage spikes that damage circuits. At 67 decibels, the noise level sits between a typical conversation and heavy traffic, making it suitable for residential neighborhoods but audible enough that neighbors will know it is running. |
