What size generator for a 30 amp camper?
A 30 amp camper can draw at most 3,600 W. With one 13,500 BTU air conditioner (2,000 W running, 3,500 W starting at the top of Champion’s range) and about 600 W of other loads, plan on a generator with 3,250 W running and 4,100 W starting watts.
How to work it out
- 1 × 2,000 W AC + 600 W other = 2,600 W running × (1 + 25%) = 3,250 W
- Starting: 2,600 W + one AC start (3,500 − 2,000 W) = 4,100 W
- 30 A service: 120 V × 30 A = 3,600 W
Many travel trailers and smaller motorhomes have 30 amp service and one roof air conditioner. That single AC is the load that decides between a small, light generator and a larger one.
Adjust for your project
More options: Headroom
- Running watts
- 3,250 W
- Starting watts
- 4,100 W
- Running watts, all together
- 2,600 W
- Most your RV service can draw
- 3,600 W
- Share of the service in use
- 72%
- Look for a generator with a TT-30R outlet (120 V, 30 A), or use the correct adapter from a 120/240 V outlet. Plug in through a surge protector.
Generator size by number of air conditioners
| Air conditioners running | Running watts | Starting watts | Share of the service in use |
|---|---|---|---|
| 0 | 750 W | 750 W | 17% |
| 1 | 3,250 W | 4,100 W | 72% |
| 2 | 5,750 W | 6,100 W | 128% |
| 3 | 8,250 W | 8,250 W | 183% |
What to know about generators for 30 amp rigs
- Without the AC, about 2,000 W. Lights, the fridge on electric, the converter, a TV and the water pump run comfortably on a 2,000 W-class inverter generator.
- With the AC, 3,500 W-class. Champion’s 3500 W dual-fuel generator, for example, is rated 3,500 running and 4,000 starting watts on gasoline, with a TT-30R RV outlet. The top-of-range AC start used here is a little over that; a smaller AC or a soft-start device brings it within reach.
- Don’t run the microwave with the AC on. 1,200 W more on top of the AC puts you near the 3,600 W limit of the rig itself.
- Fuel. That Champion model is rated 14 hours at half load on 4.7 gallons — see how long a generator runs on 5 gallons of gas.
The bigger rigs are on what size generator for a 50 amp RV with 2 AC units. For boondocking without the generator running all day, see how much solar for an RV.
Different size? Use the full RV Generator Size Calculator.
What you’ll need
- Inverter generator (about 2,000–3,500 W)Premium price
Quieter and more fuel-thrifty at light loads than an open-frame generator, with clean power for electronics. Many have a 30 A RV outlet.
See options on Amazon (opens in a new tab) - 30 A RV surge protectorMid-range price
Plugs in between the pedestal or generator and your RV cord to catch wiring faults and voltage spikes before they reach the rig.
See options on Amazon (opens in a new tab) - Battery-operated carbon monoxide alarmBudget price
CPSC advises battery or battery-backup CO alarms whenever a generator is in use. Look for UL 2034 certification and test monthly.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
What size generator for a 30 amp camper without air conditioning?
About 1,875 W running for 1,500 W of other loads — a 2,000 W-class generator.
What size generator for a 30 amp camper with a 15,000 BTU AC?
About 3,875 W running and 5,100 W starting watts.
What size generator for a 30 amp RV with the AC and microwave together?
About 4,750 W running — and 106% of the 3,600 W service, so the rig’s breaker is the limit.
Other common sizes
- What size generator for a 50 amp RV with 2 AC units — 8,125 W running / 8,500 W starting
Sources
- Champion Power Equipment — Generator Wattage Chart (opens in a new tab) — Typical running and starting watts for household, RV and job-site appliances (a manufacturer’s planning chart — your nameplate wins).
- Champion Power Equipment — 3500-Watt Dual Fuel Generator (model 201213) specifications (opens in a new tab) — 3,500 running / 4,000 starting watts on gasoline; 14 h at 50% load on 4.7 gal; 10.5 h at 50% load on a 20 lb propane tank; 120 V 30 A TT-30R RV outlet.
- Champion Power Equipment — 8500-Watt Dual Fuel Inverter (model 201175) specifications (opens in a new tab) — 120/240 V 14-50R outlet — the plug shape a 50 A RV uses.
- U.S. Consumer Product Safety Commission — Portable Generator Hazards (Safety Alert 5123, 2021) (opens in a new tab) — Never run a generator indoors or in a garage, even with doors open; place it outside far from doors, windows and vents; CO alarms; never “backfeed” by plugging into a wall outlet.
- U.S. Consumer Product Safety Commission — CPSC Warns Consumers in Path of Storms to Take Precautions When Using Portable Generators (July 24, 2020) (opens in a new tab) — “Use your generator OUTSIDE your house ONLY, at least 20 feet from your home”; make sure you have working CO alarms.