RV generator sizing, connections and safe operation
Choose an RV generator from its continuous output, compatible connection and ability to start the actual loads while supplying what is already running. Check fuel and altitude conditions as well as the air-conditioner manual. A model name, peak wattage or locked-rotor amps multiplied by voltage cannot settle the match alone.
A 2200 model does not provide 2200 watts continuously
Honda lists EU2200i output as 2,200 W maximum and 1,800 W rated. With an assumed 1,500-W running load and 400-W charger load, the total is 1,900 W, or 100 W above the rated output, before any startup requirement.
This example is not a tested air-conditioner pairing. Use the actual demand, outlet and cord ratings. Parallel operation requires manufacturer-approved compatible models and equipment; do not assume two model-name wattages simply become usable output at every receptacle.
Read Dometic’s guidance with its qualification
The September 2016 Dometic manual lists general generator guidance of 3.5 kW for one specified roof unit and 5 kW for two, with total RV usage, altitude and maintenance still relevant. Identify the exact model and controls before transferring that guidance.
Compressor locked-rotor current is not a complete startup waveform. Current times voltage gives apparent power without a power-factor qualification, not automatically real watts; it also does not describe the duration and voltage response of a start. Check the generator and appliance guidance or an approved verified pairing.
Altitude and fuel can change the usable output
The Onan KY operator manual gives 3,720 W at 2,500 feet and 3,300 W at 5,500 feet for its 4.0-kW example. That is 420 W less at the higher altitude. It is that manual’s example, not a derating table for every portable or another fuel configuration.
| Question | Evidence to obtain |
|---|---|
| Running and startup demand | Actual appliances and manufacturer matching guidance |
| Fuel and elevation | Exact generator’s rating and operating instructions |
| Connection and transfer | Approved inlet, transfer and grounding/protection arrangement |
| Site use | Current generator permission, hours and noise rules |
| Storage and service | Model-specific hour and calendar intervals |
Portable exhaust and installed exhaust need their correct instructions
CPSC’s portable-generator guidance requires outdoor operation away from openings and warns against enclosed use. Never run a portable in an RV bay, garage or partly enclosed space. A permanent onboard unit instead requires its approved installation, maintained exhaust and own operating instructions.
A working CO alarm does not make exhaust exposure acceptable. Use portable generator care, Onan care and battery power stations versus portable generators for the actual equipment and operating decision.