Buying a portable generator: the features that matter
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Quick answer
Champion says most 2,000 square foot homes need 5,000 to 7,500 watts, so open-frame portables in the 7,500 to 9,200 running watt class leave headroom for home backup. Look for electric start, a 120/240V 30A locking outlet (L14-30R), a wheel kit and a carbon monoxide shut-off. Champion's 7,500 and 9,200 watt electric start models run up to 10 hours at half load on a 7.7 gallon tank. They weigh about 200 pounds and rate 74 dBA at 23 feet. Run any portable outdoors at least 20 feet from the house.
Open-frame portable or inverter
Portable generators come in two builds. Open-frame units give more watts for home backup. Inverters are quieter and lighter, with clean power for electronics. Champion's 7,500 watt open-frame model is rated 74 dBA at 23 feet, which it compares to a vacuum cleaner. Its 2,500 watt inverter is 53 dBA. If quiet matters more than watts, see our portable inverter generator guide.
Compare two common home-backup sizes
| Champion 7500W (201547) | Champion 9200W (201494) | |
|---|---|---|
| Starting / running watts | 9,375 / 7,500 | 11,500 / 9,200 |
| Run time | Up to 10 h at 50% load | Up to 10 h at 50% load |
| Tank | 7.7 gal | 7.7 gal |
| 30A locking outlet (L14-30R) | Yes | Yes |
| Noise at 23 ft | 74 dBA | 74 dBA |
| Weight | 204 lb | 203 lb |
| Start | Electric, battery included | Electric, battery included |
| CO shut-off | CO Shield | CO Shield |
The 9,200 watt unit adds 1,700 running watts for about the same weight and run time. That headroom helps if your list includes a well pump or several motor loads. Size from your own list: running watts plus the biggest starting load. Our generator for your house guide shows how.
The outlet that makes a transfer switch possible
A 120/240V 30A locking outlet, labeled L14-30R, puts the generator's 120/240V output on one twist-lock plug. Both Champion units above have one. They also carry two 120V 20A GFCI household duplex outlets for cords. The 7,500 watt model adds a 14-50R outlet. If you plan to feed house circuits, have a qualified electrician install a properly rated transfer switch and inlet, and confirm it matches this outlet. NFPA's generator safety sheet says that connection must follow the National Electrical Code and local codes.
Features worth paying attention to
- Electric start. Champion includes the battery on both units above. Pull-starting a large engine in a storm can be hard.
- Wheel kit. At about 200 pounds, wheels are not optional. Champion's 201547 includes solid 9.5 inch wheels.
- CO shut-off. The U.S. Consumer Product Safety Commission tells buyers to look for one. Champion notes its CO Shield is not a substitute for an indoor CO alarm.
- Run time. Compare run times at the same load. Many listings use 50% load, while some inverters quote 25%.
- Dual fuel. If you want propane as a backup fuel, see our dual fuel generator guide.
Where and how to run it
CPSC says an average of about 100 people die in the U.S. each year from carbon monoxide poisoning from portable generators. Run the generator outside only, at least 20 feet from the house, and never in a garage, basement, crawlspace or shed. Do not run it on a porch or in a carport, and point the exhaust away from doors, windows and vents. NFPA adds:
- Install carbon monoxide alarms in the home.
- Let the generator cool before refueling.
- Use heavy-duty outdoor-rated cords with an intact grounding pin.
What to look for when you buy
7,500 running watt electric start generator with CO shut-off (example: Champion 201547)
Best for: Fridge, sump pump, furnace fan and lights in a typical home
Champion lists 9,375 starting and 7,500 running watts, up to 10 hours at 50% load, an L14-30R outlet, electric start with battery, a wheel kit and CO Shield.
Watch out: It weighs 204 pounds and is 74 dBA at 23 feet.
See options on Amazon (opens Amazon in a new tab)9,200 running watt electric start generator with CO shut-off (example: Champion 201494)
Best for: Homes adding a well pump or more motor loads
Champion lists 11,500 starting and 9,200 running watts, up to 10 hours at 50% load on 7.7 gallons, an L14-30R outlet and CO Shield.
Watch out: It weighs 203 pounds and runs as loud as the 7,500 watt unit.
See options on Amazon (opens Amazon in a new tab)L14-30 generator power cord
Best for: Connecting the generator's L14-30R outlet to a transfer switch inlet
A cord with the matching L14-30 plug carries the generator's 120/240V output to an inlet box wired to the transfer switch.
Watch out: Have your electrician confirm the inlet and cord type before you buy.
See options on Amazon (opens Amazon in a new tab)Generator cover for running in wet weather
Best for: Running the generator safely in rain or snow
CPSC says to follow the maker's shock-hazard instructions in bad weather, which may include an NFPA-rated noncombustible generator tent.
Watch out: Use only a cover or tent your generator's maker allows while it runs.
See options on Amazon (opens Amazon in a new tab)Questions people ask
- What size portable generator do I need for a house?
- Add your running watts plus the largest starting load. Champion says most 2,000 square foot homes need 5,000 to 7,500 watts.
- What is an L14-30R outlet for?
- It is a 120/240V 30A locking outlet. If you add a transfer switch, your electrician will confirm the matching inlet and cord.
- How long does a portable generator run on a tank?
- Champion's 7,500 and 9,200 watt models run up to 10 hours at 50% load on a 7.7 gallon tank. More load means less time.
- Do I still need a CO alarm if the generator has a CO shut-off?
- Yes. Champion says its CO Shield is not a substitute for an indoor CO alarm, and NFPA says to install CO alarms in the home.
Sources
- 7500W Electric Start Generator with CO Shield (201547), Champion Power Equipment
- 9200W Electric Start Generator (201494), Champion Power Equipment
- 2500W Inverter with CO Shield (201317), Champion Power Equipment
- What Size Generator Do I Need?, Champion Power Equipment
- Generator Safety tip sheet, National Fire Protection Association
- As Winter Storms Threaten Millions in the U.S., CPSC Issues Safety Tips, U.S. Consumer Product Safety Commission